:root {
    --primary-color: #0f172a;
    --accent-color: #2563eb;
    --accent-hover: #1d4ed8;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-gray: #64748b;
    --border: #e2e8f0;
    --effect-bg: #eff6ff;
    --effect-text: #1d4ed8;
}

* { box-sizing: border-box; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    line-height: 1.6;
    margin: 0;
    color: var(--primary-color);
    background: var(--bg-color);
}

.container { max-width: 1100px; margin: 0 auto; padding: 0 20px; }
a { text-decoration: none; color: inherit; }

/* Header */
header {
    background: #fff;
    padding: 12px 0 16px;
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--border);
    box-shadow: 0 1px 8px rgba(15, 23, 42, 0.06);
}

.header-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
    min-height: 60px;
}

.site-logo {
    margin: 0;
    line-height: 0;
}

.site-logo a {
    display: inline-flex;
    align-items: center;
}

.logo-img {
    display: block;
    height: 40px;
    width: auto;
    max-width: min(300px, 88vw);
}

@media (max-width: 480px) {
    .logo-img {
        height: 34px;
        max-width: 88vw;
    }
}

.header-guide-link {
    font-weight: 600;
    color: var(--accent-color);
    font-size: 0.9rem;
}

.lang-pill {
    font-size: 0.75rem;
    font-weight: 700;
    padding: 4px 10px;
    border-radius: 999px;
    background: #e2e8f0;
    color: #475569;
}


.search-bar-wrap {
    max-width: 1100px;
    margin: 8px auto 0;
    padding: 0 20px;
}

.search-input {
    width: 100%;
    padding: 12px 16px;
    font-size: 1rem;
    border: 1px solid var(--border);
    border-radius: 10px;
    background: #f8fafc;
}

.search-input:focus {
    outline: 2px solid var(--accent-color);
    border-color: var(--accent-color);
    background: #fff;
}

.theme-filter-buttons {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px;
    max-width: 1100px;
    margin: 12px auto 0;
    padding: 0 20px;
}

.theme-button {
    padding: 5px 12px;
    font-size: 0.8rem;
    font-weight: 600;
    border: 1px solid var(--border);
    border-radius: 999px;
    background: #fff;
    cursor: pointer;
    color: var(--text-gray);
}

.theme-button.active {
    background: var(--accent-color);
    color: #fff;
    border-color: var(--accent-color);
}

.count-badge {
    margin-left: 4px;
    opacity: 0.85;
    font-size: 0.75rem;
}

/* Main */
.content-wrapper {
    max-width: 1100px;
    margin: 0 auto;
    padding: 24px 20px 48px;
}

.section-title {
    font-size: 1.15rem;
    margin-bottom: 16px;
}

.category-section {
    margin-bottom: 36px;
}

.category-section:last-child {
    margin-bottom: 0;
}

.category-section .section-title {
    padding-bottom: 8px;
    border-bottom: 2px solid var(--border);
}

.section-view-all {
    margin-top: 12px;
    text-align: right;
}

.section-view-all a {
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--accent-color);
}

.section-title-link {
    color: inherit;
    transition: color 0.15s;
}

.section-title-link:hover {
    color: var(--accent-color);
}

/* Featured categories */
body.is-searching #list-section {
    margin-top: 0;
}

body.is-searching #list-section .category-section:first-child .section-title {
    margin-top: 0;
}

.featured-categories-section {
    margin-bottom: 40px;
}

.featured-category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 14px;
}

.featured-category-card {
    display: flex;
    flex-direction: column;
    gap: 6px;
    padding: 18px 16px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    transition: border-color 0.15s, box-shadow 0.15s, transform 0.15s;
}

.featured-category-card:hover {
    border-color: #93c5fd;
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.1);
    transform: translateY(-2px);
}

.featured-category-card.is-empty {
    opacity: 0.72;
}

.featured-category-emoji {
    font-size: 1.4rem;
    line-height: 1;
}

.featured-category-label {
    margin: 0;
    font-size: 1rem;
    font-weight: 700;
}

.featured-category-desc {
    margin: 0;
    font-size: 0.82rem;
    color: var(--text-gray);
    line-height: 1.45;
    flex: 1;
}

.featured-category-count {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--accent-color);
}

/* Category landing page */
.breadcrumb {
    font-size: 0.85rem;
    color: var(--text-gray);
    margin-bottom: 20px;
}

.breadcrumb a {
    color: var(--accent-color);
    font-weight: 600;
}

.breadcrumb span[aria-hidden="true"] {
    margin: 0 8px;
}

.category-hero {
    margin-bottom: 28px;
    padding: 24px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 14px;
}

.category-hero-emoji {
    margin: 0 0 8px;
    font-size: 2rem;
    line-height: 1;
}

.category-hero-title {
    margin: 0 0 10px;
    font-size: 1.65rem;
    letter-spacing: -0.02em;
}

.category-hero-desc {
    margin: 0 0 10px;
    color: var(--text-gray);
    max-width: 640px;
}

.category-hero-meta {
    margin: 0;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--accent-color);
}

/* Grids */
.insight-grid, .guide-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 16px;
}

.insight-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    overflow: hidden;
    transition: box-shadow 0.2s, transform 0.2s;
}

.insight-card:hover {
    box-shadow: 0 8px 24px rgba(37, 99, 235, 0.12);
    transform: translateY(-2px);
}

.insight-card-link { display: block; }

.effect-block {
    background: var(--effect-bg);
    color: var(--effect-text);
    font-size: 1.75rem;
    font-weight: 800;
    padding: 16px 20px;
    letter-spacing: -0.02em;
}

.effect-block--detail {
    border-radius: 12px;
    margin-bottom: 20px;
    font-size: 2.25rem;
}

.card-visual {
    position: relative;
    aspect-ratio: 16 / 9;
    overflow: hidden;
    background: #1e293b;
}

.card-thumb {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.effect-overlay {
    position: absolute;
    left: 12px;
    bottom: 12px;
    background: rgba(15, 23, 42, 0.88);
    color: #93c5fd;
    font-size: 1.25rem;
    font-weight: 800;
    padding: 6px 12px;
    border-radius: 8px;
}

.card-content { padding: 16px 20px 20px; }

.card-preview {
    font-size: 1rem;
    font-weight: 600;
    color: var(--primary-color);
    margin: 0 0 12px;
    line-height: 1.5;
}

.card-title {
    font-size: 1.05rem;
    margin: 0 0 8px;
    line-height: 1.35;
}

.card-summary {
    font-size: 0.9rem;
    color: var(--text-gray);
    margin: 0 0 12px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    align-items: center;
    margin-bottom: 10px;
}

.meta-context {
    font-size: 0.78rem;
    color: var(--text-gray);
}

.card-tags { display: flex; flex-wrap: wrap; gap: 6px; }

.tag {
    font-size: 0.72rem;
    font-weight: 600;
    padding: 3px 8px;
    border-radius: 6px;
    background: #f1f5f9;
    color: #475569;
}

.confidence-badge {
    font-size: 0.72rem;
    font-weight: 700;
    padding: 3px 8px;
    border-radius: 6px;
    text-transform: capitalize;
}

.badge-meta_analysis, .badge-meta { background: #dbeafe; color: #1e40af; }
.badge-ab_test, .badge-ab { background: #dcfce7; color: #166534; }
.badge-study { background: #fef3c7; color: #92400e; }
.badge-estimate { background: #f1f5f9; color: #64748b; }

.empty-state {
    grid-column: 1 / -1;
    text-align: center;
    padding: 60px 20px;
    color: var(--text-gray);
}

.guide-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 18px;
    display: block;
}

.guide-card:hover { border-color: var(--accent-color); }

.guide-list-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 16px;
}

.guide-list-card {
    display: block;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    overflow: hidden;
    transition: box-shadow 0.2s, transform 0.2s, border-color 0.2s;
}

.guide-list-card:hover {
    border-color: #93c5fd;
    box-shadow: 0 8px 24px rgba(37, 99, 235, 0.1);
    transform: translateY(-2px);
}

.guide-list-card .card-visual {
    aspect-ratio: 16 / 9;
    max-height: 160px;
}

.guide-detail-visual {
    max-height: 220px;
    margin-bottom: 24px;
}

.detail-date {
    margin: 0 0 16px;
    color: var(--text-gray);
    font-size: 0.9rem;
}

.page-nav-actions {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
    margin-top: 40px;
}

.back-btn-secondary {
    background: #fff;
    color: var(--accent-color);
    border: 1px solid var(--accent-color);
}

.back-btn-secondary:hover {
    background: #eff6ff;
    color: var(--accent-hover);
}

.view-all-container { text-align: center; margin: 20px 0 36px; }

.btn-view-all {
    display: inline-block;
    padding: 8px 20px;
    border-radius: 8px;
    border: 1px solid var(--accent-color);
    color: var(--accent-color);
    font-weight: 600;
    font-size: 0.9rem;
}

/* Detail */
.detail-container {
    max-width: 720px;
    margin: 0 auto;
    padding: 32px 20px 64px;
}

.detail-visual {
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 24px;
    aspect-ratio: 16 / 9;
}

.detail-hero-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.detail-visual-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(15, 23, 42, 0.5) 0%, transparent 50%);
    display: flex;
    align-items: flex-end;
    padding: 20px;
}

.detail-visual .effect-hero {
    font-size: 2rem;
    font-weight: 800;
    color: #93c5fd;
    background: rgba(15, 23, 42, 0.85);
    padding: 8px 14px;
    border-radius: 8px;
    margin: 0;
}

.detail-title { font-size: 1.75rem; margin: 0 0 12px; line-height: 1.25; }

.detail-hook {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin: 0 0 14px;
    line-height: 1.45;
}

.detail-summary {
    color: var(--text-gray);
    font-size: 0.95rem;
    margin: 0 0 16px;
    line-height: 1.55;
}

.detail-badges { display: flex; flex-wrap: wrap; gap: 8px; }

.share-bar {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 12px;
    margin: 16px 0 20px;
    padding: 14px 16px;
    background: var(--effect-bg);
    border: 1px solid #bfdbfe;
    border-radius: 10px;
}

.share-bar-label {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text-gray);
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.share-bar-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.share-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 36px;
    padding: 0 14px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: #fff;
    color: var(--primary-color);
    font-size: 0.875rem;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: border-color 0.15s, background 0.15s;
}

.share-btn:hover {
    border-color: var(--accent-color);
    background: var(--effect-bg);
    color: var(--accent-color);
}

.share-btn:disabled {
    opacity: 0.85;
    cursor: default;
}

.share-btn-icon {
    width: 40px;
    min-width: 40px;
    height: 40px;
    padding: 0;
}

.share-icon {
    display: block;
    width: 18px;
    height: 18px;
}

.share-btn-x:hover { color: #000; }

.share-btn-linkedin:hover { color: #0a66c2; }

.share-bar-hint {
    flex: 1 1 100%;
    margin: 0;
    font-size: 0.78rem;
    line-height: 1.45;
    color: var(--text-gray);
}

.fact-sheet {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 20px 24px;
    margin-bottom: 28px;
}

.fact-row {
    display: grid;
    grid-template-columns: 100px 1fr;
    gap: 12px;
    padding: 10px 0;
    border-bottom: 1px solid #f1f5f9;
}

.fact-row:last-child { border-bottom: none; }

.fact-label {
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--text-gray);
}

.fact-value { font-size: 0.95rem; }

.detail-content {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 24px 28px;
    margin-bottom: 24px;
}

.detail-content h2 { font-size: 1.2rem; margin-top: 1.5em; }
.detail-content h2:first-child { margin-top: 0; }

.sources-box {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 20px 24px;
    margin-bottom: 24px;
}

.sources-box ul { margin: 0; padding-left: 20px; }
.sources-box a { color: var(--accent-color); }

.related-section { margin-bottom: 32px; }

.related-grid {
    display: grid;
    gap: 10px;
}

.related-card {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 10px 14px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 10px;
}

.related-card:hover { border-color: var(--accent-color); }

.related-thumb {
    width: 72px;
    height: 48px;
    object-fit: cover;
    border-radius: 6px;
    flex-shrink: 0;
}

.related-text { display: flex; flex-direction: column; gap: 4px; min-width: 0; }

.related-effect {
    font-weight: 800;
    color: var(--effect-text);
    font-size: 0.9rem;
}

.related-title {
    font-size: 0.9rem;
    font-weight: 600;
    line-height: 1.35;
}

.detail-back { text-align: center; }

.back-btn {
    display: inline-block;
    padding: 10px 24px;
    background: var(--accent-color);
    color: #fff;
    border-radius: 8px;
    font-weight: 600;
}

.back-btn:hover { background: var(--accent-hover); }

/* Footer */
footer {
    border-top: 1px solid var(--border);
    background: #fff;
    padding: 32px 20px;
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-gray);
}

.footer-status {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 16px;
}

.status-badge {
    padding: 6px 14px;
    background: #f1f5f9;
    border-radius: 999px;
    font-size: 0.85rem;
}

.footer-links a { color: var(--accent-color); margin: 0 8px; }

@media (max-width: 600px) {
    .effect-hero { font-size: 2.25rem; }
    .fact-row { grid-template-columns: 1fr; gap: 4px; }
    .insight-grid { grid-template-columns: 1fr; }
}