/**
 * FORTH Theme - Clean CSS Rebuild
 * 統一されたクラス名とシンプルな構造
 */

/* ==========================================================================
   理論注釈スタイル
   ========================================================================== */
.forth-theory-disclaimer {
    margin-top: 50px;
    padding: 15px 20px;
    background: #f8f9fa;
    border-left: 3px solid #dee2e6;
    border-radius: 5px;
}

.forth-theory-disclaimer p {
    margin: 0 !important;
    color: #6c757d;
    font-size: 0.85rem;
    line-height: 1.6;
}

.forth-theory-disclaimer small {
    margin: 0;
    padding: 0;
}

/* forth要素内の最後のpタグのマージンを削除 */
[class*="forth-"] p:last-child {
    margin-bottom: 0 !important;
}

/* ==========================================================================
   リセット & ベース
   ========================================================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: #1a1a1a;
    background: #ffffff;
}

a {
    color: #2563eb;
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: #1d4ed8;
}

/* ==========================================================================
   共通コンテナ
   ========================================================================== */
.forth-container,
.forth-header-container,
.forth-nav-container,
.forth-footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 40px;
}

/* スマホ版調整 */
@media (max-width: 768px) {
    /* 基本コンテナ */
    .forth-container,
    .forth-header-container,
    .forth-nav-container,
    .forth-footer-container {
        padding: 0 15px;
        max-width: 100%;
    }

    /* セクションのパディング調整 */
    .forth-section {
        padding: 40px 0 !important;
    }

    .forth-section-content {
        max-width: 100% !important;
        padding: 0 15px !important;
    }

    /* ヒーローセクション調整 */
    .forth-hero,
    .forth-profile-hero,
    .forth-overview-hero {
        padding: 60px 0 !important;
        min-height: auto !important;
    }

    .forth-hero-content,
    .forth-profile-hero-content,
    .forth-overview-hero-content {
        padding: 0 15px !important;
        max-width: 100% !important;
    }

    /* 無駄な余白削除 */
    .forth-researcher-profile,
    .forth-overview,
    .forth-page {
        padding: 0 !important;
    }

    /* コンテナ内のコンテナを調整 */
    .forth-container .forth-container,
    .forth-section .forth-section-content .forth-container {
        padding: 0 !important;
    }

    /* ボックス要素の調整 */
    .forth-shock-card,
    .forth-intro-card,
    .forth-participate-card,
    .forth-role,
    .forth-quest-stage,
    .forth-philo-card {
        padding: 20px !important;
    }

    /* 記事コンテンツのパディングを削減 */
    .forth-article-content {
        padding: 15px !important;
    }

    /* 記事フッター・ナビゲーションのモバイル対応 */
    .forth-post-navigation {
        grid-template-columns: 1fr !important;
        gap: 20px !important;
        padding: 25px 15px !important;
        margin: 40px 0 30px !important;
    }

    .forth-post-navigation::before {
        display: none !important;
    }

    .forth-nav-prev,
    .forth-nav-next {
        grid-column: 1 !important;
        width: 100% !important;
    }

    .forth-nav-prev a,
    .forth-nav-next a {
        padding: 20px !important;
        gap: 15px !important;
    }

    .forth-nav-prev a:hover {
        transform: translateX(0) scale(1.02) !important;
    }

    .forth-nav-next a:hover {
        transform: translateX(0) scale(1.02) !important;
    }

    .forth-nav-arrow {
        font-size: 1.5rem !important;
    }

    .forth-nav-label {
        font-size: 0.75rem !important;
    }

    .forth-nav-title {
        font-size: 0.95rem !important;
        -webkit-line-clamp: 3 !important;
    }

    /* 言語切り替えボタン - モバイル */
    .forth-translation-switcher {
        padding: 20px 0 !important;
        margin: 30px 0 !important;
    }

    .forth-lang-switch {
        padding: 12px 24px !important;
        font-size: 0.9rem !important;
    }

    /* タグクラウド - モバイル */
    .forth-tag-cloud {
        padding: 20px !important;
        gap: 8px !important;
        margin: 20px 0 !important;
        justify-content: center !important;
    }

    .forth-tag-cloud::before {
        font-size: 80px !important;
        top: -15px !important;
        right: -15px !important;
    }

    .forth-tag {
        padding: 8px 16px !important;
        font-size: 0.85rem !important;
    }

    /* アーカイブページ - モバイル */
    .forth-archive-hero {
        padding: 50px 0 40px !important;
    }

    .forth-archive-icon {
        font-size: 45px !important;
    }

    .forth-archive-title {
        font-size: 32px !important;
    }

    .forth-archive-subtitle {
        font-size: 16px !important;
        letter-spacing: 1px !important;
    }

    .forth-archive-description {
        font-size: 16px !important;
        padding: 0 20px !important;
    }

    .forth-filter-bar {
        flex-direction: column !important;
        gap: 15px !important;
        padding: 20px 0 !important;
    }

    .forth-filter-info,
    .forth-filter-sort {
        width: 100% !important;
    }

    .forth-sort-select {
        width: 100% !important;
    }

    .forth-posts-grid {
        grid-template-columns: 1fr !important;
        gap: 25px !important;
    }

    .forth-post-card {
        border-radius: 12px !important;
    }

    .forth-post-thumbnail {
        height: 180px !important;
    }

    .forth-thumb-placeholder {
        font-size: 50px !important;
    }

    .forth-post-content {
        padding: 20px !important;
    }

    .forth-post-title {
        font-size: 18px !important;
    }

    .forth-post-excerpt {
        font-size: 14px !important;
    }

    /* コメントセクション - モバイル */
    .forth-comments-area {
        margin-top: 40px !important;
        padding-top: 30px !important;
    }

    .forth-comment-form {
        padding: 20px !important;
    }

    .forth-comment .children {
        margin-left: 20px !important;
    }

    .forth-comment-body {
        padding: 15px !important;
    }

    .forth-comment-author {
        flex-direction: row !important;
        gap: 10px !important;
    }

    .forth-comment-avatar {
        width: 40px !important;
        height: 40px !important;
    }

    .forth-lang-switch {
        padding: 10px 20px !important;
        font-size: 0.9rem !important;
    }

    /* タイトルサイズ調整 */
    h1 { font-size: 1.8rem !important; }
    h2 { font-size: 1.5rem !important; }
    h3 { font-size: 1.2rem !important; }

    /* リストの余白調整 */
    ul, ol {
        padding-left: 20px !important;
    }
}

/* ==========================================================================
   ヘッダー
   ========================================================================== */
.forth-header {
    background: #ffffff;
    border-bottom: 2px solid #e5e7eb;
    position: relative;
    z-index: 9999; /* 常に最前面に表示 */
}

.forth-header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

/* モバイル時のヘッダー調整 */
@media (max-width: 768px) {
    /* ヘッダーのアクションを非表示 */
    .forth-header-actions {
        display: none;
    }

    .forth-header-brand .forth-tagline {
        display: none;
    }
}

.forth-header-brand {
    display: flex;
    align-items: baseline;
    gap: 15px;
}

.forth-logo {
    font-size: 24px;
    font-weight: 700;
    color: #0f172a;
}

.forth-logo:hover {
    color: #0f172a;
}

.forth-tagline {
    font-size: 14px;
    color: #64748b;
}

.forth-header-actions {
    display: flex;
    align-items: center;
    gap: 20px;
}

.forth-lang {
    display: flex;
    gap: 5px;
}

.forth-lang-btn {
    padding: 5px 12px;
    background: #f3f4f6;
    color: #475569;
    border-radius: 6px;
    font-size: 14px;
    transition: all 0.2s;
}

.forth-lang-btn:hover,
.forth-lang-btn.active {
    background: #2563eb;
    color: #ffffff;
}

.forth-btn-login {
    padding: 6px 16px;
    background: #0f172a;
    color: #ffffff;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 500;
    transition: background 0.2s;
}

.forth-btn-login:hover {
    background: #1e293b;
    color: #ffffff;
}

/* ==========================================================================
   ナビゲーション
   ========================================================================== */
.forth-nav {
    background: #f8f9fa;
    border-bottom: 1px solid #e5e7eb;
}

.forth-nav-menu {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
}

.forth-nav-menu li {
    margin: 0;
}

.forth-nav-menu a {
    display: block;
    padding: 12px 20px;
    color: #475569;
    font-weight: 500;
    border-bottom: 3px solid transparent;
    transition: all 0.2s;
}

.forth-nav-menu a:hover {
    background: #ffffff;
    color: #0f172a;
    border-bottom-color: #2563eb;
}


/* ==========================================================================
   ヒーローセクション
   ========================================================================== */
.forth-hero {
    padding: 80px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
    color: white;
    min-height: 90vh;
    display: flex;
    align-items: center;
    background: #0a0a0a;
}

/* Canvas アニメーション背景 */
.forth-hero-canvas {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.forth-hero-content {
    position: relative;
    z-index: 3;
}

.forth-hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    /* 半透明の暗い背景 + 細かいメッシュパターン */
    background:
        /* メッシュパターン（最前面） */
        repeating-linear-gradient(
            0deg,
            transparent,
            transparent 3px,
            rgba(0, 0, 0, 0.08) 3px,
            rgba(0, 0, 0, 0.08) 4px
        ),
        repeating-linear-gradient(
            90deg,
            transparent,
            transparent 3px,
            rgba(0, 0, 0, 0.08) 3px,
            rgba(0, 0, 0, 0.08) 4px
        ),
        /* 暗いグラデーション背景（背面） */
        linear-gradient(135deg, rgba(15, 23, 42, 0.7) 0%, rgba(30, 41, 59, 0.75) 100%);
    z-index: 2;
}

.forth-hero-hook {
    margin-bottom: 30px;
}

.forth-hero-question {
    display: inline-block;
    font-size: 1.3rem;
    font-weight: 300;
    color: #fbbf24;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
    animation: float-text 3s ease-in-out infinite;
}

@keyframes float-text {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.forth-hero-simple {
    font-size: 1.5rem;
    line-height: 2;
    font-weight: 400;
}

.forth-hero-participate {
    margin: 40px 0;
}

.forth-countdown {
    display: inline-block;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 20px 40px;
    border-radius: 50px;
    border: 2px solid rgba(251, 191, 36, 0.5);
}

.forth-countdown-label {
    display: block;
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 5px;
}

.forth-countdown-time {
    display: block;
    font-size: 2rem;
    font-weight: bold;
    color: #fbbf24;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.forth-hero-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    color: #fbbf24;
    padding: 8px 20px;
    border-radius: 25px;
    font-weight: bold;
    font-size: 0.9rem;
    margin-bottom: 20px;
    border: 2px solid #fbbf24;
    animation: glow 2s ease-in-out infinite alternate;
}

@keyframes glow {
    from { box-shadow: 0 0 5px rgba(251, 191, 36, 0.5); }
    to { box-shadow: 0 0 20px rgba(251, 191, 36, 0.8), 0 0 30px rgba(251, 191, 36, 0.6); }
}

.forth-hero-title {
    font-size: 56px;
    font-weight: 700;
    color: white;
    margin-bottom: 10px;
    letter-spacing: -1px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.forth-hero-subtitle {
    font-size: 24px;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 30px;
    font-weight: 300;
}

.forth-hero-statement {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 30px;
    margin: 30px auto;
    max-width: 800px;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.forth-hero-statement p {
    font-size: 20px;
    line-height: 1.8;
    margin: 0;
    color: white;
}

.forth-hero-actions {
    margin-top: 40px;
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

.forth-btn-primary, .forth-btn-secondary {
    display: inline-block;
    padding: 15px 30px;
    border-radius: 50px;
    font-weight: bold;
    text-decoration: none;
    transition: all 0.3s;
    font-size: 16px;
}

.forth-btn-primary {
    background: #fbbf24;
    color: #1e293b;
    border: 2px solid #fbbf24;
}

.forth-btn-primary:hover {
    background: white;
    color: #0ea5e9;
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
}

.forth-btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.forth-btn-secondary:hover {
    background: white;
    color: #0ea5e9;
    transform: translateY(-2px);
}

/* ==========================================================================
   セクション共通
   ========================================================================== */
.forth-section {
    padding: 40px 0;
}

.forth-section:nth-child(even) {
    background: #f8f9fa;
}

.forth-section-title {
    font-size: 36px;
    font-weight: 600;
    color: #0f172a;
    text-align: center;
    margin-bottom: 40px;
}

/* ==========================================================================
   カード（Key Points）
   ========================================================================== */
.forth-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.forth-card {
    background: #ffffff;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    text-align: center;
}

.forth-card-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.forth-card-title {
    font-size: 20px;
    font-weight: 600;
    color: #0f172a;
    margin-bottom: 15px;
}

.forth-card-text {
    font-size: 15px;
    color: #475569;
    line-height: 1.6;
}

/* ==========================================================================
   最新記事
   ========================================================================== */
.forth-posts {
    max-width: 900px;
    margin: 0 auto;
}

.forth-post-item {
    display: flex;
    align-items: center;
    padding: 20px 0;
    border-bottom: 1px solid #e5e7eb;
}

.forth-post-item:last-child {
    border-bottom: none;
}

.forth-post-date {
    flex: 0 0 100px;
    font-size: 14px;
    color: #6b7280;
}

.forth-post-title {
    flex: 1;
    margin: 0 20px;
    font-size: 18px;
}

.forth-post-title a {
    color: #0f172a;
    font-weight: 500;
}

.forth-post-title a:hover {
    color: #2563eb;
}

.forth-post-type {
    flex: 0 0 auto;
    padding: 4px 12px;
    background: #eff6ff;
    color: #3b82f6;
    font-size: 12px;
    border-radius: 6px;
    text-transform: uppercase;
    font-weight: 500;
}

/* ==========================================================================
   リンクカード
   ========================================================================== */
.forth-link-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    max-width: 900px;
    margin: 0 auto;
}

.forth-link-card {
    background: #ffffff;
    padding: 30px;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    transition: all 0.2s;
}

.forth-link-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
}

.forth-link-icon {
    display: block;
    font-size: 36px;
    margin-bottom: 15px;
}

.forth-link-card h3 {
    font-size: 18px;
    font-weight: 600;
    color: #0f172a;
}

/* ==========================================================================
   フッター
   ========================================================================== */
.forth-footer {
    background: #0f172a;
    color: #cbd5e1;
    padding: 40px 0;
    margin-top: 60px;
}

.forth-footer-content {
    text-align: center;
}

.forth-footer p {
    margin: 5px 0;
}

.forth-footer-note {
    font-size: 14px;
    color: #94a3b8;
}

/* ==========================================================================
   記事ページ（Single Post）
   ========================================================================== */
.forth-single {
    background: #f8f9fa;
    min-height: calc(100vh - 200px);
    padding: 40px 0;
}

/* 2カラムレイアウト */
.forth-layout-2col {
    display: grid;
    grid-template-columns: 1fr 320px;
    gap: 40px;
    align-items: start;
}

.forth-main {
    background: #ffffff;
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
    overflow: hidden;
}

.forth-article {
    background: #ffffff;
    border-radius: 12px;
    overflow: hidden;
}

.forth-article-header {
    text-align: center;
    padding: 40px 30px;
    border-bottom: 2px solid #e5e7eb;
}

.forth-article-title {
    font-size: 42px;
    font-weight: 700;
    color: #0f172a;
    margin: 0 0 20px;
    line-height: 1.2;
}

/* 記事メタ情報の階層的レイアウト */
.forth-article-meta-wrapper {
    margin: 20px 0 30px;
}

.forth-meta-row {
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px;
}

/* 第1行：日付と基本情報 */
.forth-meta-primary {
    justify-content: center;
    font-size: 14px;
    color: #64748b;
    padding-bottom: 12px;
    border-bottom: 1px solid #e5e7eb;
}

.forth-meta-date {
    display: flex;
    align-items: center;
    gap: 6px;
    color: #64748b;
}

.forth-meta-date .forth-icon {
    width: 16px;
    height: 16px;
    color: #94a3b8;
}

.forth-meta-separator {
    color: #cbd5e1;
    font-weight: 300;
}

.forth-meta-type {
    background: #eff6ff;
    color: #3b82f6;
    padding: 4px 12px;
    border-radius: 6px;
    font-weight: 500;
    text-transform: uppercase;
    font-size: 12px;
}

/* 第2行：カテゴリー */
.forth-meta-categories {
    justify-content: center;
    padding-top: 8px;
}

.forth-meta-label {
    color: #94a3b8;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.forth-meta-categories .cat-links {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.forth-category-badge {
    display: inline-block;
    padding: 6px 12px;
    background: #f1f5f9;
    color: #475569;
    border-radius: 20px;
    font-size: 13px;
    text-decoration: none;
    transition: all 0.2s;
    border: 1px solid #e2e8f0;
}

.forth-category-badge:hover {
    background: #e2e8f0;
    color: #334155;
    transform: translateY(-1px);
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

/* 言語バッジ */
.language-badge {
    background: #fef3c7;
    color: #92400e;
    padding: 4px 10px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 500;
}

/* モバイル表示の調整 */
@media (max-width: 768px) {
    .forth-article-meta-wrapper {
        margin: 15px 0 20px;
    }

    .forth-meta-row {
        gap: 8px;
        font-size: 13px;
    }

    .forth-meta-primary {
        padding-bottom: 10px;
    }

    .forth-meta-categories {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }

    .forth-category-badge {
        padding: 5px 10px;
        font-size: 12px;
    }
}

/* 記事本文 */
.forth-article-content {
    padding: 40px 30px;
    font-size: 17px;
    line-height: 1.8;
    color: #334155;
}

.forth-article-content h2 {
    font-size: 32px;
    font-weight: 600;
    color: #0f172a;
    margin: 50px 0 25px;
    padding-bottom: 10px;
    border-bottom: 2px solid #e5e7eb;
}

.forth-article-content h3 {
    font-size: 26px;
    font-weight: 600;
    color: #1e293b;
    margin: 40px 0 20px;
}

.forth-article-content h4 {
    font-size: 22px;
    font-weight: 600;
    color: #334155;
    margin: 30px 0 15px;
}

.forth-article-content p {
    margin: 0 0 25px;
}

.forth-article-content ul,
.forth-article-content ol {
    margin: 0 0 25px;
    padding-left: 30px;
}

.forth-article-content li {
    margin-bottom: 10px;
}

.forth-article-content blockquote {
    margin: 30px 0;
    padding: 20px 30px;
    background: #f8f9fa;
    border-left: 4px solid #3b82f6;
    font-style: italic;
    color: #475569;
}

.forth-article-content pre {
    background: #1e293b;
    color: #e2e8f0;
    padding: 25px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 30px 0;
}

.forth-article-content code {
    background: #f1f5f9;
    color: #e11d48;
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 0.9em;
}

.forth-article-content pre code {
    background: transparent;
    color: #e2e8f0;
    padding: 0;
}

.forth-article-content table {
    width: 100%;
    margin: 30px 0;
    border-collapse: collapse;
}

.forth-article-content th,
.forth-article-content td {
    padding: 12px;
    text-align: left;
    border: 1px solid #e5e7eb;
}

.forth-article-content th {
    background: #f8f9fa;
    font-weight: 600;
    color: #0f172a;
}

.forth-article-content img {
    max-width: 100%;
    height: auto;
    margin: 30px 0;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

/* 記事フッター */
.forth-article-footer {
    padding: 40px 0;
    border-top: 1px solid #e5e7eb;
}

/* 言語切り替えボタン */
.forth-translation-switcher {
    margin: 40px 0;
    text-align: center;
    padding: 30px 0;
    position: relative;
}

.forth-translation-switcher::before,
.forth-translation-switcher::after {
    content: '';
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 1px;
    background: linear-gradient(90deg, transparent, #e2e8f0, transparent);
}

.forth-translation-switcher::before {
    top: 0;
}

.forth-translation-switcher::after {
    bottom: 0;
}

.forth-lang-switch {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    padding: 14px 32px;
    background: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    color: white;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.95rem;
    letter-spacing: 0.3px;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.forth-lang-switch:hover {
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.4);
    background: linear-gradient(135deg, #8b5cf6 0%, #6366f1 100%);
    color: white;
}

.forth-lang-icon {
    font-size: 1.3em;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

/* タグクラウド */
.forth-tag-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin: 30px 0;
    padding: 25px;
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    border-radius: 15px;
    position: relative;
    overflow: hidden;
}

.forth-tag-cloud::before {
    content: '#';
    position: absolute;
    top: -20px;
    right: -20px;
    font-size: 120px;
    color: rgba(148, 163, 184, 0.08);
    font-weight: bold;
    transform: rotate(-15deg);
}

.forth-tag {
    display: inline-block;
    padding: 10px 20px;
    background: white;
    color: #475569;
    border: 2px solid transparent;
    background-image: linear-gradient(white, white),
                      linear-gradient(135deg, #60a5fa, #a78bfa);
    background-origin: border-box;
    background-clip: padding-box, border-box;
    border-radius: 25px;
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
    z-index: 1;
}

.forth-tag:hover {
    background-image: linear-gradient(135deg, #60a5fa, #a78bfa),
                      linear-gradient(135deg, #60a5fa, #a78bfa);
    color: white;
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 6px 20px rgba(96, 165, 250, 0.4);
}

/* 前後記事ナビゲーション */
.forth-post-navigation {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin: 60px 0 40px;
    padding: 40px;
    background: linear-gradient(135deg, #fafbfc 0%, #f3f4f6 100%);
    border-radius: 20px;
    position: relative;
}

.forth-post-navigation::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 2px;
    height: 60px;
    background: linear-gradient(180deg, transparent, #e5e7eb, transparent);
}

.forth-nav-prev,
.forth-nav-next {
    min-height: 100px;
}

.forth-nav-prev a,
.forth-nav-next a {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 25px;
    background: white;
    border-radius: 15px;
    text-decoration: none;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    height: 100%;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    border: 2px solid transparent;
    position: relative;
    overflow: hidden;
}

.forth-nav-prev a::before,
.forth-nav-next a::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(45deg, transparent, rgba(99, 102, 241, 0.1), transparent);
    transform: rotate(45deg);
    transition: all 0.6s;
    opacity: 0;
}

.forth-nav-prev a:hover,
.forth-nav-next a:hover {
    border-color: #e0e7ff;
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.15);
    background: linear-gradient(135deg, #ffffff 0%, #f0f9ff 100%);
}

.forth-nav-prev a:hover {
    transform: translateX(-8px);
}

.forth-nav-next a:hover {
    transform: translateX(8px);
}

.forth-nav-prev a:hover::before,
.forth-nav-next a:hover::before {
    opacity: 1;
    animation: shine 0.6s;
}

@keyframes shine {
    to { transform: rotate(45deg) translate(100%, 100%); }
}

.forth-nav-arrow {
    font-size: 1.8rem;
    background: linear-gradient(135deg, #6366f1, #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: bold;
    flex-shrink: 0;
    transition: transform 0.3s;
}

.forth-nav-prev a:hover .forth-nav-arrow {
    transform: translateX(-3px);
}

.forth-nav-next a:hover .forth-nav-arrow {
    transform: translateX(3px);
}

.forth-nav-content {
    display: flex;
    flex-direction: column;
    gap: 8px;
    overflow: hidden;
}

.forth-nav-label {
    font-size: 0.8rem;
    color: #94a3b8;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 600;
}

.forth-nav-title {
    font-size: 1.05rem;
    color: #1e293b;
    font-weight: 600;
    line-height: 1.4;
    overflow: hidden;
    text-overflow: ellipsis;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

.forth-nav-next {
    grid-column: 2;
}

.forth-nav-next a {
    justify-content: flex-end;
    text-align: right;
}

.tag-links {
    margin: 20px 0;
}

.tag-links a {
    display: inline-block;
    padding: 6px 12px;
    background: #f3f4f6;
    color: #475569;
    border-radius: 6px;
    margin: 0 5px 10px 0;
    font-size: 14px;
    transition: all 0.2s;
}

.tag-links a:hover {
    background: #e2e8f0;
    color: #1e293b;
}

/* 詳細データセクション（本文の直後） */
.forth-detailed-data-section {
    margin: 0 40px 40px;
    padding: 30px;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    border-radius: 12px;
    border: 1px solid #bfdbfe;
}

.forth-detailed-data-section h3 {
    font-size: 24px;
    font-weight: 600;
    color: #0f172a;
    margin: 0 0 20px;
}

.forth-data-item {
    margin-bottom: 30px;
}

.forth-data-item h4 {
    font-size: 18px;
    font-weight: 600;
    color: #1e293b;
    margin-bottom: 15px;
}

.forth-data-image img {
    width: 100%;
    max-width: 100%;
    border: 1px solid #e5e7eb;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.json-viewer-container {
    background: #1e293b;
    color: #e2e8f0;
    border-radius: 8px;
    padding: 20px;
    overflow-x: auto;
}

.json-viewer-container pre {
    margin: 0;
    font-family: 'Courier New', monospace;
    font-size: 14px;
    line-height: 1.5;
}

.button {
    display: inline-block;
    padding: 8px 16px;
    background: #3b82f6;
    color: #ffffff;
    border-radius: 6px;
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    transition: background 0.2s;
    cursor: pointer;
    border: none;
}

.button:hover {
    background: #2563eb;
    color: #ffffff;
}

/* ナビゲーション */
.post-navigation {
    padding: 40px 0;
    border-top: 2px solid #e5e7eb;
}

.nav-links {
    display: flex;
    justify-content: space-between;
}

.nav-subtitle {
    display: block;
    font-size: 14px;
    color: #64748b;
    margin-bottom: 5px;
}

.nav-title {
    font-size: 18px;
    color: #0f172a;
    font-weight: 500;
}

/* 著者署名（控えめ） */
.author-signature {
    margin: 40px;
    padding: 30px;
    background: #f8f9fa;
    border-radius: 8px;
    text-align: center;
}

.author-signature .theory-info {
    font-size: 14px;
    color: #6b7280;
    margin: 0 0 10px;
}

.author-signature .copyright-notice {
    font-size: 13px;
    color: #9ca3af;
    margin: 0;
}

/* ==========================================================================
   サイドバー
   ========================================================================== */
.forth-sidebar {
    /* スティッキーを解除（通常のスクロール） */
}

/* サイドバーウィジェット基本スタイル */
.forth-sidebar .widget {
    background: #ffffff;
    border-radius: 8px;
    padding: 25px;
    margin-bottom: 20px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

/* Google AdSense広告ウィジェット - 300px固定・センタリング */
.forth-sidebar .widget_ad {
    background: transparent;
    padding: 0;
    box-shadow: none;
    width: auto;
    text-align: center;
}

.forth-sidebar .widget_ad .forth-ad-container {
    display: inline-block;
    width: 300px;
}

/* DMMアフィリエイトウィジェット - デザイン改善 */
.forth-sidebar .widget_dmm {
    background: linear-gradient(to bottom, #f8f9fa, #ffffff);
    border: 1px solid #e5e7eb;
    padding: 0;
    overflow: hidden;
}

.forth-sidebar .widget_dmm .widget-title {
    background: #ffffff;
    margin: 0;
    padding: 15px 20px;
    font-size: 16px;
    font-weight: 600;
    color: #0f172a;
    border-bottom: 2px solid #3b82f6;
    text-align: center;
}

.forth-sidebar .widget_dmm .forth-dmm-widget-container {
    padding: 20px 10px;
    text-align: center;
}

.forth-sidebar .widget-title {
    font-size: 18px;
    font-weight: 600;
    color: #0f172a;
    margin: 0 0 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #3b82f6;
}

.forth-sidebar ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.forth-sidebar li {
    padding: 8px 0;
    border-bottom: 1px solid #f1f5f9;
}

.forth-sidebar li:last-child {
    border-bottom: none;
}

.forth-sidebar a {
    color: #475569;
    font-size: 15px;
    transition: color 0.2s;
}

.forth-sidebar a:hover {
    color: #2563eb;
}

/* お問い合わせウィジェット */
.widget_contact {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.widget_contact .widget-title {
    color: white;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

.contact-widget-content {
    text-align: center;
    padding: 10px 0;
}

.contact-widget-content p {
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 15px;
}

.contact-widget-btn {
    display: inline-block;
    background: white;
    color: #667eea !important;
    padding: 10px 20px;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s;
}

.contact-widget-btn:hover {
    background: #f8f9fa;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

/* ==========================================================================
   アーカイブページ - モダンデザイン
   ========================================================================== */
.forth-archive {
    background: #ffffff;
    min-height: calc(100vh - 200px);
}

/* ヒーローセクション */
.forth-archive-hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 80px 0 60px;
    position: relative;
    overflow: hidden;
}

.forth-archive-hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 1px, transparent 1px);
    background-size: 20px 20px;
    transform: rotate(45deg);
    animation: float 20s linear infinite;
}

@keyframes float {
    0% { transform: rotate(45deg) translateY(0); }
    100% { transform: rotate(45deg) translateY(50px); }
}

.forth-archive-hero-content {
    text-align: center;
    color: white;
    position: relative;
    z-index: 1;
}

.forth-archive-icon {
    font-size: 60px;
    display: block;
    margin-bottom: 20px;
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.forth-archive-title {
    font-size: 48px;
    font-weight: 700;
    margin: 0 0 10px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
}

.forth-archive-subtitle {
    font-size: 20px;
    opacity: 0.95;
    margin: 0 0 20px;
    font-weight: 300;
    letter-spacing: 2px;
    text-transform: uppercase;
}

.forth-archive-description {
    font-size: 18px;
    opacity: 0.9;
    max-width: 700px;
    margin: 20px auto 0;
    line-height: 1.6;
}

/* フィルターバー */
.forth-filter-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 30px 0;
    border-bottom: 2px solid #f1f5f9;
    margin-bottom: 40px;
}

.forth-post-count {
    font-size: 15px;
    color: #64748b;
    font-weight: 500;
}

.forth-sort-select {
    padding: 10px 16px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    background: white;
    color: #475569;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s;
}

.forth-sort-select:hover,
.forth-sort-select:focus {
    border-color: #667eea;
    outline: none;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

/* ポストグリッド */
.forth-posts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: 35px;
    margin-bottom: 60px;
}

.forth-post-card {
    background: #ffffff;
    border-radius: 16px;
    overflow: hidden;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
}

.forth-post-card-inner {
    height: 100%;
    display: flex;
    flex-direction: column;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    border-radius: 16px;
    overflow: hidden;
}

.forth-post-card:hover {
    transform: translateY(-8px);
}

.forth-post-card:hover .forth-post-card-inner {
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

/* アイキャッチなしカードデザイン */
.forth-post-card-no-thumb {
    border-top: none;
    overflow: visible;
}

.forth-post-card-no-thumb .forth-post-card-inner {
    position: relative;
}

.forth-post-type-indicator {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
}

.forth-type-icon {
    position: absolute;
    top: 20px;
    left: 20px;
    width: 48px;
    height: 48px;
    background: #f3f4f6;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    z-index: 2;
}

.forth-post-card-no-thumb .forth-post-content {
    padding: 20px;
    padding-top: 80px !important;
}

.forth-post-card-no-thumb .forth-lang-badge {
    position: absolute;
    top: 20px;
    right: 20px;
    background: white;
    color: #475569;
    padding: 4px 10px;
    border-radius: 6px;
    font-size: 11px;
    font-weight: 600;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    z-index: 2;
}

/* サムネイル */
.forth-post-thumbnail {
    position: relative;
    overflow: hidden;
    height: 220px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.forth-post-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s ease;
}

.forth-post-card:hover .forth-post-thumbnail img {
    transform: scale(1.1);
}

.forth-no-thumb {
    display: flex;
    align-items: center;
    justify-content: center;
}

.forth-thumb-placeholder {
    font-size: 60px;
    opacity: 0.3;
    color: white;
}

/* 言語バッジ */
.forth-lang-badge {
    position: absolute;
    top: 15px;
    right: 15px;
    background: rgba(255, 255, 255, 0.95);
    color: #667eea;
    padding: 5px 10px;
    border-radius: 20px;
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.5px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    z-index: 2;
}

/* コンテンツエリア */
.forth-post-content {
    padding: 25px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.forth-post-header {
    margin-bottom: 15px;
}

.forth-post-meta {
    display: flex;
    gap: 12px;
    align-items: center;
    font-size: 13px;
    color: #94a3b8;
    margin-bottom: 12px;
}

.forth-icon-calendar::before {
    content: '📅';
    margin-right: 4px;
}

.forth-post-category {
    background: linear-gradient(135deg, #fce7f3 0%, #f3e7fc 100%);
    color: #9333ea;
    padding: 3px 10px;
    border-radius: 12px;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
}

.forth-post-title {
    font-size: 20px;
    font-weight: 700;
    margin: 0;
    line-height: 1.3;
}

.forth-post-title a {
    color: #1e293b;
    text-decoration: none;
    background: linear-gradient(to right, #667eea, #667eea);
    background-size: 0% 2px;
    background-repeat: no-repeat;
    background-position: left bottom;
    transition: background-size 0.3s ease;
}

.forth-post-title a:hover {
    background-size: 100% 2px;
}

.forth-post-excerpt {
    font-size: 15px;
    color: #64748b;
    line-height: 1.6;
    margin-bottom: 20px;
    flex: 1;
}

/* Read Moreボタン */
.forth-post-footer {
    margin-top: auto;
    padding-top: 20px;
    border-top: 1px solid #f1f5f9;
}

.forth-read-more {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: #667eea;
    font-weight: 600;
    text-decoration: none;
    font-size: 14px;
    transition: all 0.3s ease;
    position: relative;
}

.forth-read-more span {
    position: relative;
}

.forth-arrow-icon {
    transition: transform 0.3s ease;
}

.forth-read-more:hover {
    color: #764ba2;
}

.forth-read-more:hover .forth-arrow-icon {
    transform: translateX(4px);
}

/* ==========================================================================
   コメントセクション
   ========================================================================== */
.forth-comments-area {
    margin-top: 60px;
    padding-top: 40px;
    border-top: 2px solid #e2e8f0;
}

.forth-comments-title {
    font-size: 24px;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 30px;
}

/* コメントリスト */
.forth-comment-list {
    list-style: none;
    margin: 0 0 40px;
    padding: 0;
}

.forth-comment {
    margin-bottom: 30px;
}

.forth-comment-body {
    background: #f8fafc;
    border-radius: 12px;
    padding: 20px;
    position: relative;
}

.forth-comment-meta {
    margin-bottom: 15px;
}

.forth-comment-author {
    display: flex;
    align-items: center;
    gap: 15px;
}

.forth-comment-avatar {
    border-radius: 50%;
    border: 2px solid white;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.forth-comment-author-info {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.forth-comment-author-name {
    font-weight: 600;
    color: #0f172a;
    font-style: normal;
}

.forth-comment-author-name a {
    color: inherit;
    text-decoration: none;
}

.forth-comment-date {
    font-size: 13px;
    color: #64748b;
}

.forth-comment-content {
    color: #475569;
    line-height: 1.6;
    margin: 15px 0;
}

.forth-comment-content p {
    margin-bottom: 10px;
}

.forth-comment-content p:last-child {
    margin-bottom: 0;
}

.forth-comment-actions {
    display: flex;
    gap: 15px;
    font-size: 14px;
}

.forth-comment-reply a,
.forth-comment-edit a {
    color: #667eea;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

.forth-comment-reply a:hover,
.forth-comment-edit a:hover {
    color: #764ba2;
}

.forth-comment-awaiting {
    background: #fef3c7;
    color: #92400e;
    padding: 8px 12px;
    border-radius: 6px;
    font-size: 14px;
    margin: 10px 0;
}

/* 子コメント（返信） */
.forth-comment .children {
    list-style: none;
    margin: 20px 0 0 40px;
    padding: 0;
}

/* コメントフォーム */
.forth-comment-form {
    background: white;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    padding: 30px;
    margin-top: 40px;
}

.forth-comment-form h3 {
    font-size: 20px;
    font-weight: 700;
    color: #1e293b;
    margin: 0 0 20px;
}

.forth-comment-notes {
    font-size: 14px;
    color: #64748b;
    margin-bottom: 20px;
}

.forth-comment-notes .required-field-message {
    display: block;
    margin-top: 5px;
}

.forth-logged-in-as {
    font-size: 14px;
    color: #64748b;
    margin-bottom: 20px;
    padding: 12px;
    background: #f1f5f9;
    border-radius: 8px;
}

.forth-logged-in-as a {
    color: #667eea;
    text-decoration: none;
    font-weight: 500;
}

.forth-logged-in-as a:hover {
    color: #764ba2;
}

/* フォームフィールド */
.forth-comment-form-author,
.forth-comment-form-email,
.forth-comment-form-url,
.forth-comment-form-comment {
    margin-bottom: 20px;
}

.forth-comment-form label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    color: #475569;
    margin-bottom: 8px;
}

.forth-comment-form .required {
    color: #ef4444;
}

.forth-comment-form input[type="text"],
.forth-comment-form input[type="email"],
.forth-comment-form input[type="url"],
.forth-comment-form textarea {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid #cbd5e1;
    border-radius: 8px;
    font-size: 15px;
    color: #1e293b;
    background: white;
    transition: all 0.3s;
}

.forth-comment-form input:focus,
.forth-comment-form textarea:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.forth-comment-form textarea {
    min-height: 120px;
    resize: vertical;
    line-height: 1.5;
}

/* 送信ボタン */
.forth-comment-submit {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 12px 28px;
    border: none;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}

.forth-comment-submit:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(102, 126, 234, 0.3);
}

.forth-comment-submit:active {
    transform: translateY(0);
}

/* キャンセルリンク */
#cancel-comment-reply-link {
    color: #ef4444;
    text-decoration: none;
    font-size: 14px;
    margin-left: 15px;
}

#cancel-comment-reply-link:hover {
    text-decoration: underline;
}

/* コメントナビゲーション */
.forth-comment-navigation {
    display: flex;
    justify-content: space-between;
    margin: 30px 0;
    padding: 20px 0;
    border-top: 1px solid #e2e8f0;
}

.forth-comment-navigation a {
    color: #667eea;
    text-decoration: none;
    font-weight: 500;
}

.forth-comment-navigation a:hover {
    color: #764ba2;
}

/* 検索結果ページ */
.forth-search-header {
    margin-bottom: 40px;
}

.forth-search-title {
    font-size: 32px;
    color: #0f172a;
    margin: 0 0 10px;
}

.forth-search-title span {
    color: #2563eb;
    font-weight: 700;
}

.forth-search-count {
    font-size: 16px;
    color: #64748b;
}

.forth-posts-list {
    display: flex;
    flex-direction: column;
    gap: 30px;
    margin-bottom: 40px;
}

.forth-search-result {
    background: #ffffff;
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

.forth-result-header {
    margin-bottom: 15px;
}

.forth-result-title {
    font-size: 24px;
    margin: 0 0 10px;
}

.forth-result-meta {
    display: flex;
    gap: 15px;
    font-size: 14px;
    color: #64748b;
}

.forth-result-type {
    background: #f3f4f6;
    padding: 2px 8px;
    border-radius: 4px;
}

.forth-result-excerpt {
    font-size: 16px;
    color: #475569;
    line-height: 1.6;
    margin-bottom: 15px;
}

/* 404ページ */
.forth-404 {
    /* 404ページでは宇宙背景を使用 */
    background: transparent;
    min-height: calc(100vh - 200px);
    display: flex;
    align-items: center;
}

.forth-main-centered {
    width: 100%;
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
    padding: 40px 20px;
}

.forth-404-content {
    /* 404専用CSSで上書き - 宇宙テーマのため透明背景 */
    background: transparent;
    padding: 40px 25px;
    border-radius: 12px;
    box-shadow: none;
}

.forth-404-title {
    font-size: 120px;
    font-weight: 700;
    color: #e5e7eb;
    margin: 0;
    line-height: 1;
}

.forth-404-subtitle {
    font-size: 32px;
    color: #0f172a;
    margin: 20px 0;
}

.forth-404-message {
    font-size: 18px;
    color: #475569;
    margin-bottom: 30px;
}

.forth-404-actions {
    margin: 30px 0;
}

.forth-btn-primary {
    display: inline-block;
    padding: 12px 30px;
    background: #2563eb;
    color: #ffffff;
    border-radius: 8px;
    font-weight: 500;
    text-decoration: none;
    transition: background 0.2s;
}

.forth-btn-primary:hover {
    background: #1d4ed8;
}

.forth-404-search {
    margin: 40px 0;
}

.forth-404-search h3 {
    font-size: 18px;
    color: #0f172a;
    margin-bottom: 15px;
}

.forth-404-links {
    margin-top: 40px;
}

.forth-404-links h3 {
    font-size: 18px;
    color: #0f172a;
    margin-bottom: 15px;
}

.forth-404-links ul {
    list-style: none;
    padding: 0;
}

.forth-404-links li {
    margin: 10px 0;
}

.forth-404-links a {
    color: #2563eb;
    text-decoration: none;
}

.forth-404-links a:hover {
    text-decoration: underline;
}

/* ==========================================================================
   著者ページ
   ========================================================================== */
.forth-author-page {
    background: #f8f9fa;
    padding: 40px 0;
}

.forth-main-single {
    max-width: 900px;
    margin: 0 auto;
}

.forth-author-article {
    background: #ffffff;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    overflow: hidden;
}

.forth-author-header {
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    color: #ffffff;
    padding: 40px 25px;
    text-align: center;
}

.forth-author-title {
    font-size: 42px;
    font-weight: 700;
    margin: 0;
}

.forth-author-content {
    padding: 25px;
}

.forth-author-content section {
    margin-bottom: 50px;
}

.forth-author-content h2 {
    font-size: 28px;
    color: #0f172a;
    margin: 0 0 25px;
    padding-bottom: 10px;
    border-bottom: 2px solid #e5e7eb;
}

.forth-info-box {
    background: #f8f9fa;
    padding: 25px;
    border-radius: 8px;
}

.forth-info-box dl {
    margin: 0;
}

.forth-info-box dt {
    font-weight: 600;
    color: #475569;
    margin-bottom: 5px;
}

.forth-info-box dd {
    color: #0f172a;
    margin: 0 0 20px 0;
    font-size: 18px;
}

.forth-info-box dd:last-child {
    margin-bottom: 0;
}

.forth-text-content {
    font-size: 17px;
    line-height: 1.8;
    color: #334155;
}

.forth-text-content p {
    margin-bottom: 20px;
}

.forth-text-content ul {
    margin: 20px 0;
    padding-left: 30px;
}

.forth-text-content li {
    margin-bottom: 10px;
}

.forth-policy-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-top: 20px;
}

.forth-policy-card {
    background: #f0f9ff;
    padding: 25px;
    border-radius: 8px;
    border-left: 4px solid #3b82f6;
}

.forth-policy-card h3 {
    font-size: 20px;
    color: #0f172a;
    margin: 0 0 10px;
}

.forth-policy-card p {
    color: #475569;
    margin: 0;
    line-height: 1.6;
}

.forth-disclaimer-box {
    background: #fef3c7;
    border: 1px solid #fbbf24;
    border-radius: 8px;
    padding: 25px;
}

.forth-disclaimer-box p {
    color: #78350f;
    margin: 0 0 15px;
}

.forth-disclaimer-box ul {
    margin: 15px 0;
    padding-left: 25px;
}

.forth-disclaimer-box li {
    color: #92400e;
    margin-bottom: 8px;
}

.forth-contact-info {
    background: #f8f9fa;
    padding: 25px;
    border-radius: 8px;
}

.forth-contact-info ul {
    list-style: none;
    padding: 0;
    margin: 20px 0;
}

.forth-contact-info li {
    margin-bottom: 10px;
    color: #334155;
}

.forth-privacy-note {
    font-size: 14px;
    color: #6b7280;
    font-style: italic;
    margin-top: 20px;
}

/* 広告コンテナのスタイル修正 */
.forth-ad-container {
    width: 100% !important;
    max-width: 100% !important;
    margin: 20px 0;
    display: block;
    overflow: hidden;
}

/* 記事内広告の余白調整 */
.forth-article .forth-ad-wrapper {
    padding: 0 30px;
}

.forth-ad-article-top,
.forth-ad-article-bottom,
.forth-ad-in-article {
    width: 100% !important;
    clear: both;
}

/* レスポンシブ広告のins要素 */
.forth-ad-container ins.adsbygoogle {
    width: 100% !important;
}

/* 記事フッターメタ情報 */
.forth-article-footer {
    margin: 0;
    padding: 30px;
    border-top: 1px solid #e5e7eb;
}

.forth-footer-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    flex-wrap: wrap;
}

/* タグリスト */
.forth-tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.forth-tag-item {
    padding: 4px 10px;
    background: #f3f4f6;
    border-radius: 4px;
    font-size: 13px;
    color: #64748b;
    text-decoration: none;
    transition: all 0.2s;
}

.forth-tag-item:hover {
    background: #e2e8f0;
    color: #334155;
}

/* 言語切り替えリンク */
.forth-lang-link {
    padding: 6px 12px;
    background: #3b82f6;
    color: white;
    border-radius: 6px;
    text-decoration: none;
    font-size: 14px;
    transition: all 0.2s;
    white-space: nowrap;
}

.forth-lang-link:hover {
    background: #2563eb;
    transform: translateY(-1px);
}

/* 前後記事ナビゲーション */
.forth-post-nav {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin: 40px 20px;
    padding: 20px 0;
    border-top: 1px solid #e5e7eb;
}

.forth-nav-item {
    padding: 15px;
    background: #f9fafb;
    border-radius: 8px;
    text-decoration: none;
    color: #475569;
    display: flex;
    align-items: center;
    gap: 10px;
    transition: all 0.2s;
    min-height: 60px;
}

.forth-nav-item:hover {
    background: #f3f4f6;
    transform: translateX(3px);
}

.forth-nav-item.prev {
    justify-content: flex-start;
}

.forth-nav-item.next {
    justify-content: flex-end;
    text-align: right;
}

.forth-nav-item.prev:hover {
    transform: translateX(-3px);
}

.forth-nav-item.empty {
    visibility: hidden;
}

.nav-arrow {
    font-size: 18px;
    color: #94a3b8;
}

.nav-title {
    font-size: 14px;
    line-height: 1.4;
    flex: 1;
}

/* コメントエリア */
.forth-comments-area {
    margin-top: 40px;
    padding: 30px;
    background: #f9fafb;
    border-radius: 12px;
}

.forth-comments-area .comment-respond {
    background: white;
    padding: 20px;
    border-radius: 8px;
    margin-top: 20px;
}

.forth-comments-area .comment-form textarea {
    width: 100%;
    min-height: 120px;
    padding: 12px;
    border: 1px solid #e5e7eb;
    border-radius: 6px;
    font-size: 15px;
}

.forth-comments-area .comment-form input[type="text"],
.forth-comments-area .comment-form input[type="email"],
.forth-comments-area .comment-form input[type="url"] {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid #e5e7eb;
    border-radius: 6px;
    font-size: 15px;
}

.forth-comments-area .comment-form .submit {
    background: #3b82f6;
    color: white;
    padding: 12px 24px;
    border: none;
    border-radius: 6px;
    font-size: 15px;
    cursor: pointer;
    transition: all 0.2s;
}

.forth-comments-area .comment-form .submit:hover {
    background: #2563eb;
    transform: translateY(-1px);
}

/* モバイル対応 */
@media (max-width: 768px) {
    .forth-footer-meta {
        flex-direction: column;
        align-items: flex-start;
    }

    .forth-post-nav {
        grid-template-columns: 1fr;
    }

    .forth-nav-item {
        justify-content: flex-start !important;
    }
}

/* ページネーション */
.pagination {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin: 40px 0;
}

.page-numbers {
    padding: 8px 12px;
    background: #ffffff;
    border: 1px solid #e5e7eb;
    border-radius: 6px;
    color: #475569;
    text-decoration: none;
    transition: all 0.2s;
}

.page-numbers:hover {
    background: #f3f4f6;
    border-color: #cbd5e1;
}

.page-numbers.current {
    background: #2563eb;
    color: #ffffff;
    border-color: #2563eb;
}

/* ==========================================================================
   レスポンシブ
   ========================================================================== */
@media (max-width: 991px) {
    /* 2カラムを1カラムに */
    .forth-layout-2col {
        grid-template-columns: 1fr;
        gap: 20px;
    }
}

@media (max-width: 768px) {
    .forth-header-container {
        flex-direction: column;
        align-items: flex-start;
        gap: 15px;
    }

    .forth-header-brand {
        flex-direction: column;
        gap: 5px;
    }

    .forth-tagline {
        font-size: 12px;
    }

    .forth-nav-menu {
        flex-direction: column;
    }

    .forth-nav-menu a {
        padding: 10px 20px;
    }

    .forth-hero-title {
        font-size: 36px;
    }

    .forth-hero-subtitle {
        font-size: 18px;
    }

    .forth-cards {
        grid-template-columns: 1fr;
    }

    .forth-post-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }

    .forth-link-cards {
        grid-template-columns: 1fr;
    }
}

/* ==========================================================================
   著者ページ（改訂版）
   ========================================================================== */
.forth-researcher-profile {
    background: #ffffff;
}

/* ヒーローセクション */
.forth-profile-hero {
    background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
    color: white;
    padding: 60px 20px 40px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.forth-profile-hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    z-index: 1;
}

.forth-profile-hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    margin: 0 auto;
}

.forth-profile-name {
    font-size: 3rem;
    margin: 0 0 10px;
    font-weight: 700;
}

.forth-profile-title {
    font-size: 1.25rem;
    margin: 0 0 30px;
    opacity: 0.95;
}

.forth-core-concept {
    margin-top: 40px;
}

.forth-core-statement {
    font-size: 1.3rem;
    line-height: 1.8;
    font-weight: 600;
    margin: 0;
    padding: 25px;
    background: rgba(255, 255, 255, 0.15);
    border-radius: 12px;
    backdrop-filter: blur(10px);
    border: 2px solid rgba(255, 255, 255, 0.3);
}

/* セクション共通 */
.forth-section {
    padding: 40px 20px;
    border-bottom: 1px solid #e2e8f0;
}

.forth-section:last-child {
    border-bottom: none;
}

.forth-section-content {
    max-width: 1000px;
    margin: 0 auto;
}

.forth-section h2 {
    font-size: 2rem;
    color: #0ea5e9;
    margin: 0 0 40px;
    text-align: center;
}

.ja-subtitle {
    display: block;
    font-size: 0.875rem;
    color: #64748b;
    font-weight: 400;
    margin-top: 5px;
}

/* 観測パラドックス */
.forth-observation-paradox {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin: 40px 0;
}

.forth-paradox-item {
    background: #f8fafc;
    padding: 25px;
    border-radius: 12px;
    border-left: 4px solid #0ea5e9;
}

.forth-paradox-item h3 {
    color: #0284c7;
    margin: 0 0 15px;
    font-size: 1.2rem;
}

.forth-paradox-item p {
    color: #475569;
    line-height: 1.6;
    margin: 0;
    font-size: 1.05rem;
}

.forth-theory-answer {
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    padding: 30px;
    border-radius: 12px;
    text-align: center;
    margin-top: 30px;
}

.forth-theory-answer p {
    font-size: 1.15rem;
    line-height: 1.8;
    color: #0284c7;
    margin: 0;
    font-weight: 500;
}

/* 理論の核心ポイント */
.forth-core-points {
    display: grid;
    gap: 30px;
}

.forth-point {
    display: flex;
    gap: 25px;
    align-items: flex-start;
    background: white;
    padding: 25px;
    border-radius: 12px;
    border: 1px solid #e0f2fe;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.forth-point-number {
    min-width: 50px;
    height: 50px;
    background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 1.3rem;
}

.forth-point h3 {
    color: #0284c7;
    margin: 0 0 10px;
    font-size: 1.25rem;
}

.forth-point p {
    color: #475569;
    line-height: 1.6;
    margin: 0;
}

/* 個人的理由セクション */
.forth-personal-reason {
    background: #f8fafc;
    padding: 25px;
    border-radius: 12px;
    text-align: center;
}

.forth-personal-reason p {
    font-size: 1.15rem;
    line-height: 2;
    color: #334155;
    margin: 0 0 25px;
}

.forth-personal-reason p:last-child {
    margin-bottom: 0;
}

.forth-personal-commitment {
    margin-top: 40px;
}

.forth-personal-commitment h3 {
    color: #0284c7;
    margin: 0 0 20px;
}

.forth-personal-commitment ul {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 15px;
    list-style: none;
    padding: 0;
    margin: 0;
}

.forth-personal-commitment li {
    background: white;
    padding: 15px 20px;
    border-radius: 8px;
    border-left: 3px solid #0ea5e9;
    color: #475569;
}

/* 検証リスト */
.forth-verification-list {
    display: grid;
    gap: 25px;
}

.forth-verification-item {
    background: #f0f9ff;
    padding: 25px;
    border-radius: 12px;
}

.forth-verification-item h3 {
    color: #0284c7;
    margin: 0 0 12px;
}

.forth-verification-item p {
    color: #475569;
    line-height: 1.6;
    margin: 0;
}

/* 予測 */
.forth-predictions {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
    margin-bottom: 30px;
}

.forth-prediction {
    background: white;
    padding: 25px;
    border-radius: 12px;
    border: 1px solid #e0f2fe;
}

.forth-prediction h3 {
    color: #0ea5e9;
    margin: 0 0 12px;
}

.forth-prediction p {
    color: #475569;
    line-height: 1.5;
    margin: 0;
}

.forth-testability-note {
    text-align: center;
    font-size: 1.1rem;
    line-height: 1.8;
    color: #0284c7;
    background: #f0f9ff;
    padding: 20px;
    border-radius: 12px;
}

/* Q&A */
.forth-qa-list {
    display: grid;
    gap: 25px;
}

.forth-qa-item {
    background: white;
    padding: 25px;
    border-radius: 12px;
    border-left: 4px solid #f59e0b;
}

.forth-qa-item h3 {
    color: #d97706;
    margin: 0 0 12px;
    font-size: 1.15rem;
}

.forth-qa-item p {
    color: #475569;
    line-height: 1.6;
    margin: 0;
}

/* オープンデータ */
.forth-open-data {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.forth-data-item {
    background: #f8fafc;
    padding: 30px;
    border-radius: 12px;
}

.forth-data-item h3 {
    color: #0284c7;
    margin: 0 0 20px;
}

.forth-data-item ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.forth-data-item li {
    color: #475569;
    padding: 8px 0;
    border-bottom: 1px solid #e2e8f0;
}

.forth-data-item li:last-child {
    border-bottom: none;
}

.forth-data-item p {
    color: #334155;
    line-height: 1.8;
    margin: 0;
}

/* コラボレーション新版 */
.forth-collaborate-content {
    text-align: center;
}

.forth-collaborate-content > p {
    font-size: 1.15rem;
    line-height: 1.8;
    color: #334155;
    margin: 0 0 30px;
}

.forth-need-help {
    background: #f0f9ff;
    padding: 30px;
    border-radius: 12px;
    margin: 30px 0;
}

.forth-need-help h3 {
    color: #0284c7;
    margin: 0 0 20px;
}

.forth-need-help ul {
    list-style: none;
    padding: 0;
    margin: 0;
    text-align: left;
    max-width: 600px;
    margin: 0 auto;
}

.forth-need-help li {
    padding: 10px 0;
    border-bottom: 1px solid #cbd5e1;
    color: #475569;
    line-height: 1.6;
}

.forth-need-help li:last-child {
    border-bottom: none;
}

.forth-need-help strong {
    color: #0284c7;
}

/* コンタクトボックス */
.forth-contact-box {
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    padding: 25px;
    border-radius: 20px;
    text-align: center;
}

.forth-contact-box > p {
    font-size: 1.1rem;
    color: #334155;
    margin: 0 0 25px;
}

.forth-contact-info {
    background: white;
    padding: 25px;
    border-radius: 12px;
    margin: 25px 0;
    display: inline-block;
}

.forth-contact-info p {
    color: #475569;
    margin: 5px 0;
}

.forth-contact-info a {
    color: #0ea5e9;
    text-decoration: none;
}

.forth-contact-info a:hover {
    text-decoration: underline;
}

.forth-contact-note {
    font-size: 1.05rem;
    line-height: 1.6;
    color: #64748b;
    font-style: italic;
    margin: 25px 0 0;
}

/* 研究哲学サイクル（旧版互換用に残す） */
.forth-philosophy-cycle {
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 40px 0;
    flex-wrap: wrap;
    gap: 20px;
}

.forth-cycle-item {
    background: #f0f9ff;
    padding: 20px;
    border-radius: 12px;
    width: 180px;
    text-align: center;
    position: relative;
}

.forth-cycle-number {
    width: 40px;
    height: 40px;
    background: #0ea5e9;
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    margin: 0 auto 15px;
}

.forth-cycle-item h3 {
    color: #0284c7;
    margin: 0 0 10px;
    font-size: 1.1rem;
}

.forth-cycle-item h3 span {
    display: block;
    font-size: 0.8rem;
    color: #64748b;
    font-weight: 400;
    margin-top: 5px;
}

.forth-cycle-item p {
    font-size: 0.875rem;
    color: #475569;
    margin: 0;
}

.forth-cycle-arrow {
    color: #0ea5e9;
    font-size: 2rem;
    font-weight: bold;
}

.forth-philosophy-text {
    text-align: center;
    font-size: 1.1rem;
    line-height: 1.8;
    color: #334155;
    max-width: 800px;
    margin: 40px auto 0;
}

/* ミッション */
.forth-mission-box {
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    padding: 25px;
    border-radius: 20px;
    text-align: center;
}

.forth-mission-statement {
    font-size: 1.25rem;
    line-height: 2;
    color: #0284c7;
    margin: 0;
    font-weight: 500;
}

/* ビジョンカード */
.forth-vision-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 30px;
}

.forth-vision-card {
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    border: 1px solid #e0f2fe;
    transition: transform 0.3s;
}

.forth-vision-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 12px rgba(0, 0, 0, 0.1);
}

.forth-vision-card h3 {
    color: #0ea5e9;
    margin: 0 0 15px;
}

.forth-vision-card p {
    color: #475569;
    line-height: 1.6;
    margin: 0;
}

/* タイムライン */
.forth-journey-timeline {
    position: relative;
    padding-left: 40px;
    margin: 40px 0;
}

.forth-journey-timeline::before {
    content: '';
    position: absolute;
    left: 10px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: #e0f2fe;
}

.forth-timeline-item {
    position: relative;
    margin-bottom: 40px;
}

.forth-timeline-item::before {
    content: '';
    position: absolute;
    left: -34px;
    top: 8px;
    width: 16px;
    height: 16px;
    background: #0ea5e9;
    border-radius: 50%;
    border: 3px solid white;
    box-shadow: 0 0 0 2px #e0f2fe;
}

.forth-timeline-date {
    color: #0ea5e9;
    font-weight: bold;
    margin-bottom: 10px;
}

.forth-timeline-item h3 {
    color: #1e293b;
    margin: 0 0 10px;
}

.forth-timeline-item p {
    color: #475569;
    line-height: 1.6;
    margin: 0;
}

.forth-journey-quote {
    background: #f8fafc;
    padding: 30px;
    border-radius: 12px;
    text-align: center;
    margin-top: 40px;
    border-left: 4px solid #0ea5e9;
}

.forth-journey-quote p {
    font-size: 1.1rem;
    line-height: 1.8;
    color: #334155;
    font-style: italic;
    margin: 0;
}

/* 方法論グリッド */
.forth-method-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 30px;
}

.forth-method-card {
    text-align: center;
    padding: 30px 20px;
    background: #f8fafc;
    border-radius: 12px;
    transition: background 0.3s;
}

.forth-method-card:hover {
    background: #f0f9ff;
}

.forth-method-icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.forth-method-card h3 {
    color: #0284c7;
    margin: 0 0 15px;
}

.forth-method-card p {
    color: #475569;
    font-size: 0.95rem;
    line-height: 1.6;
    margin: 0;
}

/* 現在の焦点 */
.forth-focus-list {
    display: grid;
    gap: 20px;
}

.forth-focus-item {
    background: white;
    padding: 25px;
    border-radius: 12px;
    border: 1px solid #e2e8f0;
    display: flex;
    gap: 20px;
    align-items: flex-start;
}

.forth-focus-status {
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: bold;
    text-transform: uppercase;
    white-space: nowrap;
}

.forth-focus-status.active {
    background: #dcfce7;
    color: #16a34a;
}

.forth-focus-status.planning {
    background: #fef3c7;
    color: #d97706;
}

.forth-focus-item h3 {
    color: #1e293b;
    margin: 0 0 8px;
    font-size: 1.1rem;
}

.forth-focus-item p {
    color: #64748b;
    margin: 0;
    line-height: 1.5;
}

/* オープンサイエンス */
.forth-open-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.forth-open-item {
    background: #f0f9ff;
    padding: 30px;
    border-radius: 12px;
}

.forth-open-item h3 {
    color: #0284c7;
    margin: 0 0 20px;
    font-size: 1.25rem;
}

.forth-open-item ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.forth-open-item li {
    color: #475569;
    padding: 8px 0;
    border-bottom: 1px solid rgba(148, 163, 184, 0.2);
}

.forth-open-item li:last-child {
    border-bottom: none;
}

/* リソースと制約 */
.forth-resources-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-bottom: 30px;
}

.forth-resource-box {
    padding: 30px;
    border-radius: 12px;
}

.forth-resource-box.constraints {
    background: #fef2f2;
    border: 1px solid #fecaca;
}

.forth-resource-box.advantages {
    background: #f0fdf4;
    border: 1px solid #bbf7d0;
}

.forth-resource-box h3 {
    margin: 0 0 20px;
    font-size: 1.25rem;
}

.forth-resource-box.constraints h3 {
    color: #dc2626;
}

.forth-resource-box.advantages h3 {
    color: #16a34a;
}

.forth-resource-box ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.forth-resource-box li {
    padding: 8px 0;
    color: #475569;
}

.forth-resources-note {
    text-align: center;
    font-style: italic;
    color: #64748b;
    font-size: 1.05rem;
}

/* コラボレーション */
.forth-collab-cta {
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    padding: 25px;
    border-radius: 20px;
    text-align: center;
}

.forth-collab-cta h3 {
    color: #0284c7;
    margin: 0 0 20px;
    font-size: 1.5rem;
}

.forth-collab-cta > p {
    color: #475569;
    margin: 0 0 30px;
    font-size: 1.05rem;
}

.forth-collab-types {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 25px;
    margin-top: 30px;
}

.forth-collab-type {
    background: white;
    padding: 25px 20px;
    border-radius: 12px;
    border: 1px solid #e0f2fe;
}

.forth-collab-type h4 {
    color: #0ea5e9;
    margin: 0 0 10px;
}

.forth-collab-type p {
    color: #64748b;
    margin: 0;
    font-size: 0.95rem;
}

/* 連絡先 */
.forth-connect-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.forth-connect-card {
    background: #f8fafc;
    padding: 30px;
    border-radius: 12px;
    text-align: center;
}

.forth-connect-card h3 {
    color: #0284c7;
    margin: 0 0 20px;
}

.forth-connect-card p {
    color: #475569;
    margin: 0 0 10px;
    line-height: 1.6;
}

.forth-connect-card a {
    color: #0ea5e9;
    text-decoration: none;
}

.forth-connect-card a:hover {
    text-decoration: underline;
}

/* 最終メッセージ */
.forth-final-message {
    background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
    color: white;
    text-align: center;
}

.forth-final-box {
    padding: 40px 20px;
}

.forth-final-box p {
    font-size: 1.2rem;
    line-height: 2;
    margin: 0 0 20px;
}

.forth-signature {
    font-style: italic;
    opacity: 0.95;
}

/* レスポンシブデザイン（著者ページ用） */
@media (max-width: 768px) {
    .forth-profile-name {
        font-size: 2rem;
    }

    .forth-core-statement {
        font-size: 1.1rem;
        padding: 20px;
    }

    .forth-point {
        flex-direction: column;
        gap: 15px;
    }

    .forth-point-number {
        margin: 0 auto;
    }

    .forth-philosophy-cycle {
        flex-direction: column;
    }

    .forth-cycle-arrow {
        transform: rotate(90deg);
    }

    .forth-journey-timeline {
        padding-left: 30px;
    }

    .forth-focus-item {
        flex-direction: column;
        gap: 10px;
    }
}

/* W軸説明セクション */
.forth-w-axis {
    background: linear-gradient(135deg, #f8fafc 0%, #f0f9ff 100%);
}

.forth-axis-visual {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 20px;
    margin: 40px 0;
}

.forth-axis-card {
    background: white;
    padding: 20px;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s;
}

.forth-axis-card:hover {
    transform: translateY(-5px);
}

.forth-axis-card.special {
    background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
    color: white;
    transform: scale(1.1);
}

.forth-axis-card.special:hover {
    transform: scale(1.15) translateY(-5px);
}

.forth-axis-label {
    width: 50px;
    height: 50px;
    margin: 0 auto 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: bold;
    border-radius: 50%;
}

.forth-axis-label.x {
    background: #fee2e2;
    color: #dc2626;
}

.forth-axis-label.y {
    background: #dcfce7;
    color: #16a34a;
}

.forth-axis-label.z {
    background: #e0e7ff;
    color: #4338ca;
}

.forth-axis-label.w {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid white;
}

.forth-axis-card p {
    margin: 0;
    font-size: 0.9rem;
    color: #64748b;
}

.forth-axis-card.special p {
    color: rgba(255, 255, 255, 0.9);
}

.forth-w-explanation {
    background: white;
    padding: 25px;
    border-radius: 20px;
    margin-top: 30px;
}

.forth-w-explanation h3 {
    color: #0284c7;
    margin: 0 0 20px;
    text-align: center;
}

.forth-w-properties {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 30px;
    margin-top: 30px;
}

.forth-property {
    text-align: center;
}

.forth-property-icon {
    font-size: 2.5rem;
    display: block;
    margin-bottom: 15px;
}

.forth-property h4 {
    color: #0284c7;
    margin: 0 0 10px;
}

.forth-property p {
    color: #64748b;
    margin: 0;
    font-size: 0.95rem;
}

/* 定量的予測セクション */
.forth-predictions-detailed {
    background: white;
}

.forth-predictions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 25px;
    margin: 40px 0;
}

.forth-prediction-card {
    background: #f8fafc;
    padding: 30px 20px;
    border-radius: 16px;
    text-align: center;
    border: 1px solid #e2e8f0;
    transition: all 0.3s;
}

.forth-prediction-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
}

.forth-prediction-card.highlight {
    background: linear-gradient(135deg, #fef3c7 0%, #fed7aa 100%);
    border: 2px solid #f59e0b;
}

.forth-prediction-value {
    font-size: 2.5rem;
    font-weight: bold;
    color: #0ea5e9;
    margin-bottom: 10px;
}

.forth-prediction-card.highlight .forth-prediction-value {
    color: #d97706;
}

.forth-prediction-card h3 {
    color: #1e293b;
    margin: 0 0 15px;
}

.forth-prediction-card p {
    color: #64748b;
    margin: 0;
    line-height: 1.5;
}

.forth-prediction-card code {
    display: block;
    margin-top: 10px;
    padding: 8px;
    background: rgba(14, 165, 233, 0.1);
    border-radius: 6px;
    font-size: 0.85rem;
    color: #0284c7;
}

.forth-prediction-note {
    text-align: center;
    font-size: 1.1rem;
    color: #475569;
    line-height: 1.8;
    padding: 20px;
    background: #f0f9ff;
    border-radius: 12px;
    margin-top: 20px;
}

/* 5年計画タイムライン */
.forth-roadmap {
    background: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
}

.forth-timeline-container {
    position: relative;
    padding: 40px 0;
    margin: 40px 0;
}

.forth-timeline-line {
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 4px;
    background: linear-gradient(180deg, #0ea5e9 0%, #0284c7 100%);
    transform: translateX(-50%);
}

.forth-timeline-item {
    position: relative;
    margin: 60px 0;
    display: flex;
    align-items: center;
}

.forth-timeline-item:nth-child(even) {
    flex-direction: row-reverse;
}

.forth-timeline-marker {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 60px;
    background: white;
    border: 4px solid #0ea5e9;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 1.3rem;
    color: #0ea5e9;
    z-index: 2;
}

.forth-timeline-content {
    width: 45%;
    background: white;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.forth-timeline-item:nth-child(even) .forth-timeline-content {
    margin-left: 0;
    margin-right: auto;
}

.forth-timeline-item:nth-child(odd) .forth-timeline-content {
    margin-left: auto;
    margin-right: 0;
}

.forth-timeline-content h3 {
    color: #0284c7;
    margin: 0 0 20px;
}

.forth-timeline-content ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.forth-timeline-content li {
    padding: 8px 0;
    padding-left: 25px;
    position: relative;
    color: #475569;
}

.forth-timeline-content li:before {
    content: "→";
    position: absolute;
    left: 0;
    color: #0ea5e9;
}

.forth-status {
    display: inline-block;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: bold;
    margin-top: 15px;
    background: #e2e8f0;
    color: #64748b;
}

.forth-status.current {
    background: #dcfce7;
    color: #16a34a;
}

.forth-vision-statement {
    background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
    color: white;
    padding: 25px;
    border-radius: 20px;
    text-align: center;
    margin-top: 60px;
}

.forth-vision-statement h3 {
    margin: 0 0 20px;
    font-size: 1.5rem;
}

.forth-vision-statement p {
    font-size: 1.2rem;
    line-height: 1.8;
    margin: 0;
}

.forth-vision-sub {
    display: block;
    margin-top: 10px;
    font-size: 1rem;
    opacity: 0.9;
    font-style: italic;
}

/* 数学セクション */
.forth-mathematics {
    background: #f8fafc;
}

.forth-equation-box {
    background: white;
    padding: 25px;
    border-radius: 20px;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.forth-equation {
    font-size: 1.8rem;
    font-weight: bold;
    color: #0284c7;
    font-family: 'Courier New', monospace;
    padding: 30px;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    border-radius: 12px;
    margin-bottom: 30px;
}

.forth-equation-params {
    display: flex;
    justify-content: center;
    gap: 40px;
    flex-wrap: wrap;
}

.forth-param {
    color: #475569;
    font-size: 1.05rem;
}

.forth-param strong {
    color: #0284c7;
}

.forth-math-insight {
    margin-top: 30px;
    padding: 20px;
    background: #f0f9ff;
    border-radius: 12px;
    text-align: center;
}

.forth-math-insight p {
    color: #334155;
    font-size: 1.1rem;
    line-height: 1.8;
    margin: 0;
}

/* 重要性セクション */
.forth-importance-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 30px;
    margin: 40px 0;
}

.forth-importance-card {
    background: white;
    padding: 30px;
    border-radius: 16px;
    text-align: center;
    border: 2px solid #e0f2fe;
    transition: all 0.3s;
}

.forth-importance-card:hover {
    transform: translateY(-8px);
    border-color: #0ea5e9;
    box-shadow: 0 12px 24px rgba(14, 165, 233, 0.15);
}

.forth-importance-icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.forth-importance-card h3 {
    color: #0284c7;
    margin: 0 0 15px;
}

.forth-importance-card p {
    color: #64748b;
    margin: 0;
    line-height: 1.5;
}

.forth-warning-note {
    background: linear-gradient(135deg, #fef3c7 0%, #fed7aa 100%);
    border: 2px solid #f59e0b;
    border-radius: 12px;
    padding: 20px;
    margin-top: 30px;
    text-align: center;
}

.forth-warning-note p {
    color: #92400e;
    margin: 0;
    font-weight: 500;
    font-size: 1.05rem;
}

/* 研究原則 */
.forth-principles-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
}

.forth-principle {
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    padding: 25px;
    border-radius: 12px;
    border-left: 4px solid #0ea5e9;
}

.forth-principle h3 {
    color: #0284c7;
    margin: 0 0 10px;
    font-size: 1.2rem;
}

.forth-principle p {
    color: #475569;
    margin: 0;
}

/* 協力CTA */
.forth-collaboration-cta {
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
}

.forth-collab-message {
    text-align: center;
}

.forth-lead {
    font-size: 1.2rem;
    line-height: 2;
    color: #334155;
    margin-bottom: 40px;
}

.forth-collab-needs {
    background: white;
    padding: 25px;
    border-radius: 20px;
    margin-top: 40px;
}

.forth-collab-needs h3 {
    color: #0284c7;
    margin: 0 0 30px;
}

.forth-collab-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 25px;
}

.forth-collab-item {
    padding: 20px;
    background: #f8fafc;
    border-radius: 12px;
    text-align: center;
}

.forth-collab-item strong {
    display: block;
    color: #0ea5e9;
    margin-bottom: 10px;
}

.forth-collab-item p {
    color: #64748b;
    margin: 0;
    font-size: 0.95rem;
}

/* ヒーロー背景アニメーション */
.forth-hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    opacity: 0.1;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='1'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
    animation: float 20s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-20px); }
}

.forth-hypothesis-badge {
    display: inline-block;
    margin-top: 20px;
    padding: 10px 25px;
    background: rgba(251, 191, 36, 0.2);
    border: 2px solid #fbbf24;
    color: #fbbf24;
    border-radius: 30px;
    font-weight: bold;
    font-size: 0.95rem;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.8; }
}

/* 最終メッセージ */
.forth-final {
    background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
    color: white;
}

.forth-final-message blockquote {
    font-size: 1.4rem;
    line-height: 2;
    text-align: center;
    margin: 0 0 30px;
    padding: 30px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    backdrop-filter: blur(10px);
}

.forth-contact-final {
    text-align: center;
    padding: 30px;
    background: rgba(255, 255, 255, 0.15);
    border-radius: 16px;
    margin-top: 40px;
}

.forth-contact-final h3 {
    margin: 0 0 20px;
}

.forth-contact-final a {
    color: #fbbf24;
}

/* ========================================
   DMM/広告関連スタイル
======================================== */

/* ホームページDMM書籍ウィジェット */
.forth-dmm-homepage-widget {
    padding: 60px 0;
    background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
    border-top: 1px solid #e5e7eb;
}

.forth-dmm-homepage-widget h2 {
    text-align: center;
    margin-bottom: 40px;
    font-size: 28px;
    font-weight: 700;
    color: #0f172a;
    position: relative;
}

.forth-dmm-homepage-widget h2::after {
    content: '';
    display: block;
    width: 60px;
    height: 3px;
    background: #3b82f6;
    margin: 15px auto 0;
}

.forth-dmm-homepage-widget .forth-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.forth-dmm-flex {
    display: flex;
    gap: 30px;
    justify-content: center;
    align-items: stretch;
}

.forth-dmm-item {
    background: #ffffff;
    border-radius: 12px;
    padding: 25px 15px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    flex: 0 1 340px;
}

.forth-dmm-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.12);
}

.forth-dmm-item h3 {
    font-size: 18px;
    font-weight: 600;
    margin: 0 0 20px;
    padding-bottom: 15px;
    border-bottom: 1px solid #e5e7eb;
    color: #475569;
    text-align: center;
}

.forth-dmm-item .forth-dmm-widget-container {
    text-align: center;
}

/* レスポンシブ対応追加 */
@media (max-width: 991px) {
    .forth-timeline-line {
        left: 30px;
    }

    .forth-timeline-marker {
        left: 30px;
    }

    .forth-timeline-item {
        flex-direction: column !important;
        margin-left: 60px;
    }

    .forth-timeline-content {
        width: 100%;
        margin: 0 !important;
    }

    .forth-timeline-item:nth-child(even) .forth-timeline-content {
        margin: 0 !important;
    }
}

@media (max-width: 768px) {
    .forth-equation {
        font-size: 1.2rem;
        padding: 20px 10px;
        overflow-x: auto;
    }

    .forth-equation-params {
        flex-direction: column;
        gap: 15px;
    }

    .forth-prediction-value {
        font-size: 2rem;
    }

    .forth-axis-card.special {
        transform: scale(1);
    }
}

/* 衝撃の事実セクション */
.forth-shock {
    background: linear-gradient(135deg, #fef3c7 0%, #fed7aa 100%);
    padding: 50px 0;
}

.forth-shock-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 40px;
    margin-top: 50px;
}

.forth-shock-card {
    background: white;
    padding: 25px 20px;
    border-radius: 20px;
    text-align: center;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    border: 3px solid #f59e0b;
    transition: all 0.3s;
    position: relative;
}

.forth-shock-card:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: 0 15px 35px rgba(245, 158, 11, 0.3);
}

.forth-shock-card::before {
    content: '⚡';
    position: absolute;
    top: -15px;
    right: -15px;
    font-size: 30px;
    background: #f59e0b;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    animation: pulse 2s infinite;
}

.forth-shock-number {
    font-size: 3.5rem;
    font-weight: 900;
    color: #dc2626;
    margin-bottom: 15px;
    text-shadow: 2px 2px 4px rgba(220, 38, 38, 0.2);
}

.forth-shock-card h3 {
    font-size: 1.3rem;
    color: #0ea5e9;
    margin-bottom: 20px;
    font-weight: 700;
}

.forth-shock-card p {
    color: #374151;
    line-height: 1.7;
    font-size: 1.05rem;
    margin: 0;
}

/* 参加型コンテンツセクション */
.forth-challenge {
    background: #f8fafc;
    padding: 50px 0;
}

.forth-vote-box {
    background: white;
    padding: 25px;
    border-radius: 20px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
    margin-bottom: 40px;
}

.forth-vote-question {
    font-size: 1.5rem;
    color: #0f172a;
    text-align: center;
    margin-bottom: 40px;
    font-weight: 600;
}

.forth-vote-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 20px;
    max-width: 600px;
    margin: 0 auto;
}

.forth-vote-btn {
    background: white;
    border: 3px solid #e2e8f0;
    border-radius: 16px;
    padding: 25px 20px;
    cursor: pointer;
    transition: all 0.3s;
    text-align: center;
}

.forth-vote-btn:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
}

.forth-vote-btn.believe:hover {
    border-color: #10b981;
    background: #f0fdf4;
}

.forth-vote-btn.skeptic:hover {
    border-color: #f59e0b;
    background: #fef3c7;
}

.forth-vote-btn.deny:hover {
    border-color: #ef4444;
    background: #fef2f2;
}

.forth-vote-icon {
    display: block;
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.forth-vote-text {
    display: block;
    font-size: 1.1rem;
    color: #475569;
    margin-bottom: 10px;
}

.forth-vote-count {
    display: block;
    font-size: 1.5rem;
    font-weight: bold;
    color: #0ea5e9;
}

.forth-vote-note {
    text-align: center;
    color: #64748b;
    margin-top: 30px;
    font-style: italic;
}

.forth-criticism-box {
    background: white;
    padding: 25px;
    border-radius: 20px;
    border: 2px solid #fbbf24;
}

.forth-criticism-box h3 {
    color: #0284c7;
    margin-bottom: 30px;
    text-align: center;
    font-size: 1.3rem;
}

.forth-criticism-list {
    margin-bottom: 30px;
}

.forth-criticism-item {
    padding: 15px 20px;
    background: #fef3c7;
    border-radius: 12px;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 15px;
}

.forth-criticism-badge {
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: bold;
    text-transform: uppercase;
}

.forth-criticism-badge.hot {
    background: #ef4444;
    color: white;
}

.forth-criticism-badge.new {
    background: #10b981;
    color: white;
}

.forth-btn-outline {
    display: inline-block;
    padding: 12px 30px;
    border: 2px solid #0ea5e9;
    color: #0ea5e9;
    border-radius: 50px;
    text-decoration: none;
    font-weight: bold;
    transition: all 0.3s;
}

.forth-btn-outline:hover {
    background: #0ea5e9;
    color: white;
    transform: translateY(-2px);
}

/* 旧版著者ページスタイル（互換性のため維持） */
.forth-author-article {
    max-width: 1000px;
    margin: 0 auto;
}

.forth-author-header {
    text-align: center;
    margin-bottom: 3rem;
}

.forth-author-title {
    font-size: 2.5rem;
    color: #0ea5e9;
    margin-bottom: 1rem;
}

.forth-author-content section {
    margin-bottom: 3rem;
}

.forth-author-content h2 {
    color: #0ea5e9;
    border-bottom: 2px solid #e0f2fe;
    padding-bottom: 0.5rem;
    margin-bottom: 1.5rem;
}

.forth-author-content h3 {
    color: #0284c7;
    margin: 1.5rem 0 1rem;
}

.forth-info-box {
    background: #f0f9ff;
    border-left: 4px solid #0ea5e9;
    padding: 1.5rem;
    border-radius: 8px;
}

.forth-info-box dl {
    display: grid;
    grid-template-columns: 150px 1fr;
    gap: 1rem;
    margin: 0;
}

.forth-info-box dt {
    font-weight: 600;
    color: #0284c7;
}

.forth-info-box dd {
    margin: 0;
    color: #334155;
}

.forth-text-content {
    line-height: 1.8;
    color: #334155;
}

.forth-text-content ul {
    margin: 1rem 0;
    padding-left: 2rem;
}

.forth-text-content li {
    margin: 0.5rem 0;
}

.forth-policy-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.forth-policy-card {
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    padding: 1.5rem;
    border-radius: 12px;
    border: 1px solid #bae6fd;
}

.forth-policy-card h3 {
    color: #0ea5e9;
    margin: 0 0 0.5rem;
}

.forth-policy-card p {
    margin: 0;
    color: #475569;
    font-size: 0.95rem;
}

.forth-disclaimer-box {
    background: #fef3c7;
    border: 2px solid #f59e0b;
    border-radius: 12px;
    padding: 2rem;
}

.forth-disclaimer-box strong {
    color: #d97706;
    font-size: 1.1rem;
}

.forth-disclaimer-box ul {
    margin: 1rem 0;
    padding-left: 2rem;
}

.forth-disclaimer-box li {
    margin: 0.5rem 0;
    color: #92400e;
}

.forth-contact-info {
    background: #f8fafc;
    padding: 2rem;
    border-radius: 12px;
}

.forth-contact-info ul {
    list-style: none;
    padding: 0;
    margin: 1rem 0;
}

.forth-contact-info li {
    margin: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
}

.forth-contact-info li:before {
    content: "▸";
    position: absolute;
    left: 0;
    color: #0ea5e9;
}

.forth-feedback-note {
    margin-top: 1.5rem;
    padding: 1rem;
    background: #e0f2fe;
    border-radius: 8px;
    font-style: italic;
}

@media (max-width: 768px) {
    .forth-info-box dl {
        grid-template-columns: 1fr;
    }

    .forth-info-box dt {
        border-bottom: 1px solid #cbd5e1;
        padding-bottom: 0.25rem;
    }

    .forth-policy-cards {
        grid-template-columns: 1fr;
    }
}

/* ==========================================================================
   著者ページ（参加型版）スタイル
   ========================================================================== */
.forth-researcher-profile {
    background: #ffffff;
}

.forth-researcher-profile .forth-section {
    padding: 40px 0;
}

.forth-researcher-profile .forth-section-content {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

.forth-researcher-profile .forth-profile-hero {
    background: linear-gradient(135deg, #1a1a2e 0%, #0f0f1e 100%);
    padding: 60px 0;
    text-align: center;
    color: white;
    position: relative;
}

.forth-researcher-profile .forth-profile-name {
    font-size: 3rem;
    margin-bottom: 10px;
}

.forth-researcher-profile .forth-profile-title {
    font-size: 1.2rem;
    opacity: 0.9;
    margin-bottom: 30px;
}

.forth-researcher-profile .forth-profile-question {
    margin: 40px auto;
    max-width: 600px;
}

.forth-researcher-profile .forth-question-text {
    font-size: 1.4rem;
    line-height: 1.8;
    margin-bottom: 20px;
}

.forth-researcher-profile .forth-quick-vote {
    display: flex;
    gap: 15px;
    justify-content: center;
}

.forth-researcher-profile .forth-quick-btn {
    padding: 12px 24px;
    border: 2px solid white;
    background: transparent;
    color: white;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 1rem;
}

.forth-researcher-profile .forth-quick-btn:hover {
    background: white;
    color: #1a1a2e;
}

.forth-researcher-profile .forth-quick-btn.selected {
    background: white;
    color: #1a1a2e;
}

/* 3分で分かる私の挑戦 */
.forth-researcher-profile .forth-quick-intro {
    padding: 40px 0;
}

.forth-researcher-profile .forth-intro-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin: 40px auto;
    max-width: 1000px;
}

.forth-researcher-profile .forth-intro-card {
    background: linear-gradient(135deg, #f8f9fa 0%, #ffffff 100%);
    padding: 25px 20px;
    border-radius: 20px;
    text-align: center;
    position: relative;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    transition: all 0.3s;
    border: 2px solid transparent;
}

.forth-researcher-profile .forth-intro-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 30px rgba(0,0,0,0.15);
    border-color: #6c63ff;
}

.forth-researcher-profile .forth-intro-number {
    display: inline-block;
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, #6c63ff 0%, #4a42b8 100%);
    color: white;
    border-radius: 50%;
    line-height: 60px;
    font-size: 1.8rem;
    margin-bottom: 20px;
    font-weight: bold;
    box-shadow: 0 4px 15px rgba(108, 99, 255, 0.3);
}

.forth-researcher-profile .forth-intro-card h3 {
    margin: 0 0 15px 0;
    font-size: 1.4rem;
    color: #2c2c3e;
}

.forth-researcher-profile .forth-intro-card p {
    margin: 0;
    line-height: 1.6;
    color: #555;
    font-size: 1rem;
}

.forth-researcher-profile .forth-intro-card p br {
    display: block;
    content: "";
    margin-top: 5px;
}

.forth-researcher-profile .forth-intro-summary {
    background: linear-gradient(145deg, #fff3cd, #ffe9a1);
    padding: 25px;
    border-radius: 15px;
    margin-top: 40px;
    border-left: 5px solid #ffc107;
    box-shadow: 0 4px 15px rgba(255, 193, 7, 0.2);
}

.forth-researcher-profile .forth-intro-summary strong {
    color: #e68900;
    font-size: 1.1rem;
}

/* JavaScript連携用の追加スタイル */
.forth-vote-feedback {
    margin-top: 15px;
    padding: 10px;
    background: #e0f2fe;
    border-radius: 10px;
    color: #0284c7;
    font-size: 0.9rem;
    display: none;
    transition: opacity 0.3s;
}

.forth-researcher-profile .forth-quick-btn.selected {
    background: white !important;
    color: #1a1a2e !important;
    box-shadow: 0 4px 15px rgba(255, 255, 255, 0.3);
}

.forth-researcher-profile .forth-final-reveal {
    opacity: 0;
    transition: opacity 0.5s ease-in;
}

.forth-researcher-profile .forth-final-btn:disabled {
    cursor: not-allowed;
}

/* W軸説明 */
.forth-researcher-profile .forth-w-simple {
    background: #f8f9fa;
    padding: 40px 0;
}

.forth-researcher-profile .forth-dimension-game {
    max-width: 800px;
    margin: 0 auto;
}

.forth-researcher-profile .forth-game-question {
    font-size: 1.3rem;
    text-align: center;
    margin-bottom: 40px;
    color: #2c2c3e;
}

.forth-researcher-profile .forth-dimension-steps {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 15px;
    max-width: 900px;
    margin: 40px auto;
}

@media (max-width: 768px) {
    .forth-researcher-profile .forth-dimension-steps {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .forth-researcher-profile .forth-dimension-steps {
        grid-template-columns: 1fr;
    }
}

.forth-researcher-profile .forth-step {
    text-align: center;
    padding: 20px 15px;
    background: white;
    border-radius: 10px;
    transition: all 0.3s;
    min-height: 120px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
}

.forth-researcher-profile .forth-step.highlight {
    background: #6c63ff;
    color: white;
    transform: scale(1.1);
}

.forth-researcher-profile .forth-step-icon {
    font-size: 2.5rem;
    display: block;
    margin-bottom: 10px;
}

.forth-researcher-profile .forth-step p {
    margin: 0;
    font-size: 0.9rem;
    line-height: 1.4;
}

.forth-researcher-profile .forth-step p strong {
    display: block;
    font-size: 1rem;
    margin-bottom: 3px;
}

.forth-researcher-profile .forth-w {
    color: #ff6b6b;
    font-weight: bold;
}

.forth-researcher-profile .forth-w-impact {
    background: white;
    padding: 30px;
    border-radius: 15px;
    margin-top: 40px;
}

/* 検証予測 */
.forth-researcher-profile .forth-predictions-simple {
    padding: 40px 0;
}

.forth-researcher-profile .forth-prediction-timeline {
    display: flex;
    gap: 40px;
    align-items: center;
    max-width: 800px;
    margin: 40px auto;
}

.forth-researcher-profile .forth-prediction-simple {
    flex: 1;
    background: #f8f9fa;
    padding: 30px;
    border-radius: 15px;
}

.forth-researcher-profile .forth-big-number {
    font-size: 4rem;
    color: #6c63ff;
    font-weight: bold;
}

.forth-researcher-profile .forth-unit {
    font-size: 1.2rem;
    color: #666;
}

.forth-researcher-profile .forth-verification-status {
    flex: 1;
    background: white;
    padding: 30px;
    border: 2px solid #e0e0e0;
    border-radius: 15px;
}

.forth-researcher-profile .forth-status-bar {
    width: 100%;
    height: 20px;
    background: #e0e0e0;
    border-radius: 10px;
    overflow: hidden;
    margin: 20px 0;
}

.forth-researcher-profile .forth-status-progress {
    height: 100%;
    background: linear-gradient(90deg, #4caf50, #8bc34a);
    transition: width 0.5s;
}

/* 参加型セクション */
.forth-researcher-profile .forth-participate {
    background: #f8f9fa;
    padding: 40px 0;
}

.forth-researcher-profile .forth-participate-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin: 40px auto;
    max-width: 900px;
}

.forth-researcher-profile .forth-participate-card {
    background: white;
    padding: 30px;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.forth-researcher-profile .forth-open-science {
    margin-top: 50px;
    text-align: center;
}

.forth-researcher-profile .forth-open-items {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-top: 20px;
    flex-wrap: wrap;
}

.forth-researcher-profile .forth-open-item {
    text-align: center;
}

.forth-researcher-profile .forth-icon {
    font-size: 2rem;
    display: block;
    margin-bottom: 5px;
}

/* ゲームプラン */
.forth-researcher-profile .forth-gameplan {
    padding: 40px 0;
}

.forth-researcher-profile .forth-quest-map {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    margin: 40px auto;
    max-width: 1000px;
}

.forth-researcher-profile .forth-quest-stage {
    background: #f8f9fa;
    padding: 25px;
    border-radius: 15px;
    position: relative;
    transition: all 0.3s;
}

.forth-researcher-profile .forth-quest-stage.current {
    background: #6c63ff;
    color: white;
    transform: scale(1.05);
}

.forth-researcher-profile .forth-quest-stage.final {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.forth-researcher-profile .forth-stage-status {
    position: absolute;
    top: -10px;
    right: 10px;
    background: #ff6b6b;
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.8rem;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

.forth-researcher-profile .forth-research-approach {
    margin-top: 40px;
    padding: 30px;
    background: #e0f2fe;
    border-radius: 15px;
    text-align: center;
}

.forth-researcher-profile .forth-research-approach h3 {
    margin-bottom: 15px;
    color: #2c2c3e;
}

.forth-researcher-profile .forth-research-approach p {
    font-size: 1.1rem;
    line-height: 1.8;
}

/* 哲学セクション */
.forth-researcher-profile .forth-philosophy {
    background: #f8f9fa;
    padding: 40px 0;
}

.forth-researcher-profile .forth-philosophy-cards {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    margin: 40px auto;
    max-width: 1000px;
}

.forth-researcher-profile .forth-philo-card {
    background: white;
    padding: 30px;
    border-radius: 15px;
    text-align: center;
}

.forth-researcher-profile .forth-philo-card.warning {
    background: #fee2e2;
    border: 2px solid #ef4444;
}

.forth-researcher-profile .forth-emoji {
    font-size: 3rem;
    display: block;
    margin-bottom: 15px;
}

.forth-researcher-profile .forth-philosophy-quote {
    text-align: center;
    margin-top: 40px;
    padding: 30px;
    background: white;
    border-radius: 15px;
    font-style: italic;
    font-size: 1.2rem;
}

.forth-researcher-profile .forth-sub {
    display: block;
    font-size: 0.9rem;
    margin-top: 10px;
    opacity: 0.8;
}

/* コラボ募集 */
.forth-researcher-profile .forth-collab-casual {
    padding: 40px 0;
}

.forth-researcher-profile .forth-collab-roles {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin: 40px auto;
    max-width: 700px;
}

@media (max-width: 640px) {
    .forth-researcher-profile .forth-collab-roles {
        grid-template-columns: 1fr;
    }
}

.forth-researcher-profile .forth-role {
    background: linear-gradient(145deg, #ffffff, #f0f0f5);
    padding: 25px;
    border-radius: 20px;
    min-height: 100px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.08);
    transition: all 0.3s;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    gap: 10px;
}

.forth-researcher-profile .forth-role:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
    background: linear-gradient(145deg, #6c63ff, #5853d4);
    color: white;
}

.forth-researcher-profile .forth-role:hover p {
    color: rgba(255, 255, 255, 0.9);
}

.forth-researcher-profile .forth-role h3 {
    margin: 0 0 10px 0;
    font-size: 1.2rem;
}

.forth-researcher-profile .forth-role p {
    margin: 0;
    color: #666;
    font-size: 0.9rem;
    line-height: 1.4;
}

.forth-researcher-profile .forth-collab-message {
    text-align: center;
    margin-top: 40px;
    padding: 30px;
    background: #e0f2fe;
    border-radius: 15px;
    font-size: 1.1rem;
}

/* 最終メッセージ */
.forth-researcher-profile .forth-final {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 50px 0;
    color: white;
}

.forth-researcher-profile .forth-final-interactive {
    text-align: center;
    max-width: 700px;
    margin: 0 auto;
}

.forth-researcher-profile .forth-big-question {
    font-size: 1.8rem;
    line-height: 1.8;
    margin: 30px 0;
}

.forth-researcher-profile .forth-final-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin: 30px 0;
}

.forth-researcher-profile .forth-final-btn {
    padding: 15px 30px;
    background: white;
    color: #764ba2;
    border: none;
    border-radius: 30px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.3s;
}

.forth-researcher-profile .forth-final-btn:hover {
    transform: scale(1.1);
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
}

.forth-researcher-profile .forth-final-reveal {
    margin-top: 30px;
    padding: 20px;
    background: rgba(255,255,255,0.1);
    border-radius: 15px;
    font-size: 1.2rem;
    animation: fadeIn 1s;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.forth-researcher-profile .forth-contact-final {
    text-align: center;
    margin-top: 50px;
    padding-top: 30px;
    border-top: 1px solid rgba(255,255,255,0.3);
}

/* ==========================================================================
   概要ページスタイル
   ========================================================================== */
.forth-overview {
    background: #ffffff;
}

.forth-overview-hero {
    background: linear-gradient(135deg, #1a1a2e 0%, #0f0f1e 100%);
    padding: 50px 0;
    text-align: center;
    color: white;
}

.forth-overview-hero h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.forth-overview-subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
}

.forth-reading-time {
    display: inline-block;
    margin-top: 10px;
    padding: 5px 15px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    font-size: 0.9rem;
}

/* 要点セクション */
.forth-overview .forth-key-points {
    padding: 40px 0;
}

.forth-overview .forth-points-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin: 40px auto;
    max-width: 1000px;
}

.forth-overview .forth-point-card {
    background: #f8f9fa;
    padding: 30px;
    border-radius: 15px;
    text-align: center;
}

.forth-overview .forth-point-icon {
    font-size: 3rem;
    margin-bottom: 15px;
}

/* 問題と解決策 */
.forth-overview .forth-why-needed {
    background: #f8f9fa;
    padding: 40px 0;
}

.forth-overview .forth-problems-solutions {
    margin-top: 40px;
}

.forth-overview .forth-problem {
    background: white;
    padding: 30px;
    border-radius: 15px;
    margin-bottom: 30px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.forth-overview .forth-problem h3 {
    color: #2c2c3e;
    margin-bottom: 20px;
    font-size: 1.3rem;
}

.forth-overview .forth-problem-detail p {
    margin-bottom: 15px;
    line-height: 1.8;
}

.forth-overview .forth-solution {
    background: #e0f2fe;
    padding: 15px;
    border-radius: 10px;
    border-left: 4px solid #0ea5e9;
}

/* 数学セクション */
.forth-overview .forth-mathematics {
    padding: 40px 0;
}

.forth-overview .forth-equation-display {
    font-size: 1.5rem;
    text-align: center;
    padding: 30px;
    background: #f8f9fa;
    border-radius: 15px;
    margin: 20px 0;
    font-family: 'Courier New', monospace;
}

.forth-overview .forth-equation-explanation {
    background: white;
    padding: 20px;
    border-radius: 10px;
    margin-top: 20px;
}

.forth-overview .forth-implication-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-top: 30px;
}

.forth-overview .forth-impl-card {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
}

/* 予測テーブル */
.forth-overview .forth-predictions {
    background: #f8f9fa;
    padding: 40px 0;
}

.forth-overview .forth-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    background: white;
    border-radius: 10px;
    overflow: hidden;
}

.forth-overview .forth-table th {
    background: #2c2c3e;
    color: white;
    padding: 15px;
    text-align: left;
}

.forth-overview .forth-table td {
    padding: 15px;
    border-bottom: 1px solid #e0e0e0;
}

.forth-overview .forth-table tr:hover {
    background: #f5f5f5;
}

.forth-overview .forth-prediction-note {
    background: #fff3cd;
    padding: 20px;
    border-radius: 10px;
    margin-top: 30px;
    border-left: 4px solid #ffc107;
}

/* シミュレーションセクション */
.forth-overview .forth-simulations {
    padding: 40px 0;
}

.forth-overview .forth-sim-overview {
    margin-bottom: 40px;
    text-align: center;
}

.forth-overview .forth-sim-results {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    margin: 40px auto;
    max-width: 900px;
}

.forth-overview .forth-sim-card {
    background: #f8f9fa;
    padding: 30px;
    border-radius: 15px;
}

.forth-overview .forth-sim-card h3 {
    margin-bottom: 15px;
    color: #2c2c3e;
}

.forth-overview .forth-sim-card ul {
    list-style-position: inside;
    line-height: 1.8;
}

@media (max-width: 768px) {
    .forth-overview .forth-sim-results {
        grid-template-columns: 1fr;
    }
}

/* Q&Aセクション */
.forth-overview .forth-criticisms {
    padding: 40px 0;
}

.forth-overview .forth-qa-accordion {
    margin: 20px 0;
}

.forth-overview .forth-qa-item {
    margin-bottom: 20px;
}

.forth-overview .forth-qa-question {
    background: #f0f0f5;
    padding: 20px;
    cursor: pointer;
    border-left: 4px solid #6c63ff;
    transition: all 0.3s;
    border-radius: 10px;
}

.forth-overview .forth-qa-question:hover {
    background: #e8e8f0;
}

.forth-overview .forth-qa-answer {
    padding: 20px;
    background: white;
    margin-top: 10px;
    border-left: 4px solid #e0e0e0;
    border-radius: 10px;
}

/* 研究方法フロー */
.forth-overview .forth-methodology {
    background: #f8f9fa;
    padding: 40px 0;
}

.forth-overview .forth-method-flow {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin: 40px 0;
    flex-wrap: wrap;
}

.forth-overview .forth-method-step {
    flex: 1;
    text-align: center;
    padding: 20px;
    min-width: 150px;
}

.forth-overview .forth-step-number {
    display: inline-block;
    width: 50px;
    height: 50px;
    background: #6c63ff;
    color: white;
    border-radius: 50%;
    line-height: 50px;
    font-size: 1.5rem;
    margin-bottom: 15px;
}

.forth-overview .forth-method-arrow {
    font-size: 2rem;
    color: #6c63ff;
}

.forth-overview .forth-transparency-items {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    margin: 30px 0;
}

.forth-overview .forth-trans-item {
    text-align: center;
    padding: 20px;
    background: white;
    border-radius: 10px;
}

/* 今後の展望 */
.forth-overview .forth-future {
    padding: 40px 0;
}

.forth-overview .forth-timeline {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin: 40px 0;
}

.forth-overview .forth-timeline-period {
    background: #f8f9fa;
    padding: 30px;
    border-radius: 15px;
}

.forth-overview .forth-commitment {
    text-align: center;
    margin-top: 40px;
    padding: 30px;
    background: #fff3cd;
    border-radius: 15px;
    font-size: 1.1rem;
}

/* 参加の呼びかけ */
.forth-overview .forth-join {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 50px 0;
    color: white;
}

.forth-overview .forth-join-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin: 40px 0;
}

.forth-overview .forth-join-card {
    background: rgba(255,255,255,0.1);
    padding: 30px;
    border-radius: 15px;
    text-align: center;
    backdrop-filter: blur(10px);
}

.forth-overview .forth-join-card h3 {
    color: white;
    margin-bottom: 10px;
}

.forth-overview .forth-join-card p {
    color: rgba(255,255,255,0.9);
    margin-bottom: 20px;
}

.forth-overview .forth-btn-primary {
    display: inline-block;
    padding: 12px 30px;
    background: white;
    color: #764ba2;
    border-radius: 25px;
    font-weight: bold;
    transition: all 0.3s;
}

.forth-overview .forth-btn-primary:hover {
    transform: scale(1.05);
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
}

.forth-overview .forth-final-message {
    text-align: center;
    margin-top: 50px;
    font-size: 1.2rem;
    line-height: 1.8;
}

/* その他の調整 */
.forth-researcher-profile .forth-open-items {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-top: 20px;
    flex-wrap: wrap;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.forth-overview .forth-problems-solutions {
    max-width: 900px;
    margin: 40px auto;
}

.forth-overview .forth-qa-accordion {
    max-width: 900px;
    margin: 20px auto;
}

.forth-overview .forth-table {
    max-width: 900px;
    margin: 20px auto;
}

/* レスポンシブ対応（統合） */
@media (max-width: 768px) {
    /* カードやグリッドのスマホ対応 */
    .forth-shock-grid,
    .forth-posts,
    .forth-link-cards,
    .forth-participate-options,
    .forth-collab-roles,
    .forth-intro-cards,
    .forth-quest-map,
    .forth-philosophy-cards {
        grid-template-columns: 1fr !important;
        gap: 20px !important;
    }

    /* ボタンを全幅に */
    .forth-btn-primary,
    .forth-btn-secondary,
    .forth-btn-outline,
    .forth-vote-btn,
    .forth-quick-btn,
    .forth-final-btn {
        width: 100%;
        padding: 15px !important;
    }

    /* ヒーローエリアの調整 */
    .forth-hero-actions {
        flex-direction: column;
        gap: 15px;
    }

    /* 投票ボタン */
    .forth-vote-buttons {
        flex-direction: column;
        gap: 15px;
    }

    /* テーブルのスクロール対応 */
    .forth-table,
    table {
        display: block;
        overflow-x: auto;
        white-space: nowrap;
    }
    .forth-researcher-profile .forth-profile-name {
        font-size: 2rem;
    }

    .forth-researcher-profile .forth-prediction-timeline {
        flex-direction: column;
    }

    .forth-researcher-profile .forth-final-buttons {
        flex-direction: column;
        gap: 10px;
    }

    .forth-overview .forth-method-arrow {
        transform: rotate(90deg);
    }

    .forth-overview-hero h1 {
        font-size: 1.8rem;
    }

    .forth-overview .forth-table {
        font-size: 0.9rem;
    }

    .forth-overview .forth-table th,
    .forth-overview .forth-table td {
        padding: 10px;
    }
}

/* お問い合わせページスタイル */
.forth-contact-page {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

.contact-intro {
    margin-bottom: 40px;
    text-align: center;
}

.contact-intro p {
    font-size: 18px;
    color: #475569;
    line-height: 1.8;
}

.contact-info-boxes {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin: 30px 0;
}

.contact-info-boxes .info-box {
    background: #f1f5f9;
    border-radius: 12px;
    padding: 20px;
}

.contact-info-boxes .info-box h3 {
    font-size: 18px;
    margin-bottom: 15px;
    color: #1e293b;
}

.contact-info-boxes .info-box ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.contact-info-boxes .info-box li {
    padding: 5px 0;
    color: #64748b;
    font-size: 14px;
    line-height: 1.6;
}

.contact-info-boxes .info-box li:before {
    content: "・";
    margin-right: 5px;
    color: #3b82f6;
}

/* Contact Form 7 スタイル */
.forth-contact-form {
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
}

.forth-contact-form .form-group {
    margin-bottom: 25px;
}

.forth-contact-form label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #334155;
    font-size: 15px;
}

.forth-contact-form .required {
    color: #ef4444;
    margin-left: 4px;
}

.forth-contact-form .form-control {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #cbd5e1;
    border-radius: 8px;
    font-size: 15px;
    transition: all 0.3s;
}

.forth-contact-form .form-control:focus {
    outline: none;
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.forth-contact-form textarea.form-control {
    resize: vertical;
    min-height: 120px;
    font-family: inherit;
}

.forth-contact-form select.form-control {
    cursor: pointer;
}

.forth-contact-form .checkbox-group {
    display: flex;
    align-items: center;
    gap: 8px;
}

.forth-contact-form .checkbox-group input[type="checkbox"] {
    margin: 0;
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

.forth-contact-form .checkbox-group label {
    font-weight: normal;
    font-size: 14px;
    margin: 0;
    line-height: 1.4;
    display: inline;
}

/* Contact Form 7のデフォルトスタイルを上書き */
.forth-contact-form .checkbox-group p {
    display: flex;
    align-items: center;
    margin: 0;
}

.forth-contact-form .wpcf7-form-control-wrap {
    display: inline-flex;
    align-items: center;
    margin-right: 8px;
}

.forth-contact-form .wpcf7-list-item {
    display: inline-block;
    margin: 0;
}

.forth-contact-form .wpcf7-list-item input[type="checkbox"] {
    margin: 0;
    width: 18px;
    height: 18px;
    cursor: pointer;
    vertical-align: middle;
}

.forth-contact-form .checkbox-group a {
    color: #3b82f6;
    text-decoration: underline;
}

.forth-contact-form .checkbox-group a:hover {
    color: #2563eb;
}

/* チェックボックスの横並び強制 */
.forth-contact-form .wpcf7-acceptance {
    display: inline !important;
}

.forth-contact-form .wpcf7-acceptance .wpcf7-list-item {
    display: inline !important;
    margin-right: 8px !important;
}

.forth-contact-form span.wpcf7-list-item input[type="checkbox"] {
    display: inline-block !important;
    vertical-align: middle !important;
    margin-top: -2px !important;
}

.forth-contact-form .btn-submit {
    background: #3b82f6;
    color: white;
    padding: 14px 40px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}

.forth-contact-form .btn-submit:hover {
    background: #2563eb;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(59, 130, 246, 0.3);
}

.contact-form-wrapper {
    margin: 40px 0;
}

.contact-form-wrapper h2 {
    text-align: center;
    margin-bottom: 30px;
    font-size: 28px;
    color: #1e293b;
}

.contact-notes {
    background: #fef3c7;
    border: 1px solid #fbbf24;
    border-radius: 8px;
    padding: 20px;
    margin-top: 40px;
}

.contact-notes h3 {
    font-size: 18px;
    margin-bottom: 15px;
    color: #92400e;
}

.contact-notes ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.contact-notes li {
    padding: 5px 0;
    color: #78350f;
    font-size: 14px;
    line-height: 1.6;
}

.contact-notes li:before {
    content: "※";
    margin-right: 5px;
    color: #f59e0b;
}

/* Contact Form 7 レスポンス */
.wpcf7-response-output {
    margin: 20px 0;
    padding: 15px;
    border-radius: 8px;
    text-align: center;
    font-size: 15px;
}

.wpcf7-mail-sent-ok {
    background: #d1fae5;
    border: 1px solid #6ee7b7;
    color: #065f46;
}

.wpcf7-mail-sent-ng,
.wpcf7-spam-blocked {
    background: #fee2e2;
    border: 1px solid #fca5a5;
    color: #991b1b;
}

.wpcf7-validation-errors {
    background: #fef3c7;
    border: 1px solid #fcd34d;
    color: #92400e;
}

/* Contact Form 7 モバイル対応 */
@media (max-width: 768px) {
    .contact-info-boxes {
        grid-template-columns: 1fr;
    }

    .forth-contact-form {
        padding: 20px;
    }

    .forth-contact-form .btn-submit {
        width: 100%;
    }
}

/* ==========================================================================
   Footer Styles
   ========================================================================== */
.forth-footer {
    background: linear-gradient(to bottom, #1e293b, #0f172a);
    color: #e2e8f0;
    padding: 3rem 0;
    margin-top: 4rem;
}

.forth-footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.forth-footer-content {
    text-align: center;
}

.forth-footer-links {
    margin-bottom: 1.5rem;
}

.forth-footer-link {
    color: #60a5fa;
    text-decoration: none;
    padding: 0 10px;
    transition: color 0.3s;
    font-size: 15px;
}

.forth-footer-link:hover {
    color: #93c5fd;
    text-decoration: underline;
}

.forth-footer-links .separator {
    color: #475569;
    margin: 0 5px;
}

.forth-footer-note {
    font-size: 0.875rem;
    color: #94a3b8;
    margin-top: 1rem;
}

/* ==========================================================================
   Contact CTA Section
   ========================================================================== */
.forth-contact-cta {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 2.5rem;
    border-radius: 12px;
    text-align: center;
    margin: 3rem 0 2rem;
    box-shadow: 0 10px 30px rgba(102, 126, 234, 0.2);
}

.forth-contact-cta h3 {
    color: white;
    font-size: 1.75rem;
    margin-bottom: 1rem;
}

.forth-contact-cta p {
    color: rgba(255, 255, 255, 0.9);
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.forth-contact-cta .forth-btn-primary {
    background: white;
    color: #667eea;
    padding: 12px 30px;
    border-radius: 8px;
    display: inline-block;
    font-weight: 600;
    transition: all 0.3s;
    text-decoration: none;
}

.forth-contact-cta .forth-btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
    background: #f8f9fa;
}

/* ==========================================================================
   Privacy Policy Page Styles
   ========================================================================== */
.forth-privacy-page {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    line-height: 1.8;
}

.forth-privacy-page h1 {
    color: #1e293b;
    border-bottom: 3px solid #3b82f6;
    padding-bottom: 10px;
    margin-bottom: 30px;
}

.forth-privacy-page h2 {
    color: #334155;
    margin-top: 40px;
    margin-bottom: 20px;
    padding-left: 10px;
    border-left: 4px solid #3b82f6;
}

.forth-privacy-page h3 {
    color: #475569;
    margin-top: 25px;
    margin-bottom: 15px;
}

.forth-privacy-page section {
    margin-bottom: 30px;
}

.forth-privacy-page ul {
    margin: 15px 0;
    padding-left: 30px;
}

.forth-privacy-page li {
    margin: 8px 0;
    color: #475569;
}

.forth-privacy-page .updated {
    color: #64748b;
    font-size: 14px;
    margin-bottom: 30px;
}

.forth-privacy-page a {
    color: #3b82f6;
    text-decoration: underline;
}

.forth-privacy-page a:hover {
    color: #2563eb;
}

.privacy-footer {
    margin-top: 50px;
    padding-top: 30px;
    border-top: 1px solid #e2e8f0;
    color: #64748b;
}

@media (max-width: 768px) {
    .forth-privacy-page {
        padding: 15px;
    }

    .forth-privacy-page h1 {
        font-size: 24px;
    }

    .forth-privacy-page h2 {
        font-size: 20px;
    }
}

/* ==========================================================================
   Back to Top Button
   ========================================================================== */
.forth-back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border: none;
    border-radius: 50%;
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 1000;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
}

.forth-back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.forth-back-to-top:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

.forth-back-to-top:active {
    transform: translateY(-1px);
}

.forth-back-to-top svg {
    width: 24px;
    height: 24px;
}

/* モバイル版 */
@media (max-width: 768px) {
    .forth-back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
    }
}

/* ==========================================================================
   パソコン表示の左右余白調整
   ========================================================================== */
@media (min-width: 769px) {
    /* メインコンテンツエリアの左右余白 */
    .forth-page .forth-article,
    .forth-single .forth-article {
        padding-left: 40px;
        padding-right: 40px;
    }

    /* アーカイブページの余白 */
    .forth-archive .forth-main {
        padding-left: 40px;
        padding-right: 40px;
    }

    /* フロントページのセクション余白 */
    .forth-front-page .forth-section-content {
        padding-left: 40px;
        padding-right: 40px;
    }

    /* 既にコンテナでラップされている要素は二重にならないよう調整 */
    .forth-container .forth-article,
    .forth-container .forth-main {
        padding-left: 20px;
        padding-right: 20px;
    }
}