/* ==========================================================================
   Marwadi Chess - Demo About Page Stylesheet
   Modern, accessible, responsive design system for demo-about.html
   Supports seamless Light and Dark theme modes via [data-theme]
   ========================================================================== */

:root {
    --about-gold-light: #fbbf24;
    --about-gold-main: #d4af37;
    --about-gold-dark: #b45309;
    --about-gold-glow: rgba(212, 175, 55, 0.25);
    
    --about-bg-surface: #ffffff;
    --about-bg-subtle: #f8fafc;
    --about-bg-elevated: #ffffff;
    --about-border: #e2e8f0;
    --about-border-highlight: rgba(212, 175, 55, 0.4);
    
    --about-text-heading: #0f172a;
    --about-text-body: #334155;
    --about-text-muted: #64748b;
    
    --about-card-shadow: 0 4px 20px -2px rgba(0, 0, 0, 0.05), 0 2px 6px -1px rgba(0, 0, 0, 0.03);
    --about-card-hover-shadow: 0 12px 30px -4px rgba(212, 175, 55, 0.18), 0 4px 12px -2px rgba(0, 0, 0, 0.06);
}

[data-theme="dark"] {
    --about-bg-surface: #1e293b;
    --about-bg-subtle: #0f172a;
    --about-bg-elevated: #243044;
    --about-border: #334155;
    --about-border-highlight: rgba(251, 191, 36, 0.45);
    
    --about-text-heading: #f8fafc;
    --about-text-body: #cbd5e1;
    --about-text-muted: #94a3b8;
    
    --about-card-shadow: 0 4px 20px -2px rgba(0, 0, 0, 0.35);
    --about-card-hover-shadow: 0 12px 30px -4px rgba(0, 0, 0, 0.5), 0 0 15px rgba(251, 191, 36, 0.2);
}

/* Base Wrapper */
.demo-about-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px 16px 60px;
    color: var(--about-text-body);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

/* ──────────────────────────────────────────────────────────
   1. HERO SECTION
   ────────────────────────────────────────────────────────── */
.demo-about-hero {
    position: relative;
    padding: 48px 24px 40px;
    text-align: center;
    background: radial-gradient(circle at 50% 0%, var(--about-gold-glow) 0%, transparent 70%), var(--about-bg-surface);
    border: 1px solid var(--about-border);
    border-radius: 20px;
    box-shadow: var(--about-card-shadow);
    margin-bottom: 32px;
    overflow: hidden;
}

.demo-about-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 16px;
    border-radius: 9999px;
    background: rgba(212, 175, 55, 0.12);
    border: 1px solid var(--about-border-highlight);
    color: var(--about-gold-dark);
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    margin-bottom: 18px;
}

[data-theme="dark"] .demo-about-badge {
    color: var(--about-gold-light);
    background: rgba(251, 191, 36, 0.15);
}

.demo-about-title {
    font-size: clamp(28px, 4.5vw, 44px);
    font-weight: 800;
    color: var(--about-text-heading);
    line-height: 1.2;
    margin-bottom: 16px;
    letter-spacing: -0.5px;
}

.demo-about-title-highlight {
    background: linear-gradient(135deg, #d4af37, #f59e0b 80%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

.demo-about-subtitle {
    font-size: clamp(15px, 2vw, 17.5px);
    line-height: 1.7;
    max-width: 820px;
    margin: 0 auto 28px;
    color: var(--about-text-muted);
}

.demo-about-hero-actions {
    display: flex;
    justify-content: center;
    gap: 14px;
    flex-wrap: wrap;
}

.demo-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: 12px;
    font-size: 14.5px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.25s ease;
    cursor: pointer;
    border: none;
}

.demo-btn-primary {
    background: linear-gradient(135deg, #d4af37, #b45309);
    color: #ffffff !important;
    box-shadow: 0 4px 14px rgba(212, 175, 55, 0.35);
}

.demo-btn-primary:hover {
    background: linear-gradient(135deg, #f59e0b, #92400e);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(212, 175, 55, 0.5);
    color: #ffffff !important;
}

.demo-btn-secondary {
    background: var(--about-bg-subtle);
    color: var(--about-text-heading) !important;
    border: 1px solid var(--about-border);
}

.demo-btn-secondary:hover {
    background: var(--about-bg-elevated);
    border-color: var(--about-border-highlight);
    transform: translateY(-2px);
    color: var(--about-gold-dark) !important;
}

[data-theme="dark"] .demo-btn-secondary:hover {
    color: var(--about-gold-light) !important;
}

/* ──────────────────────────────────────────────────────────
   2. PLATFORM STATS GRID
   ────────────────────────────────────────────────────────── */
.demo-stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
    gap: 16px;
    margin-bottom: 40px;
}

.demo-stat-card {
    background: var(--about-bg-surface);
    border: 1px solid var(--about-border);
    border-radius: 16px;
    padding: 20px 16px;
    text-align: center;
    box-shadow: var(--about-card-shadow);
    transition: transform 0.25s ease, box-shadow 0.25s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.demo-stat-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--about-card-hover-shadow);
    border-color: var(--about-border-highlight);
}

.demo-stat-icon {
    font-size: 24px;
    color: var(--about-gold-main);
    margin-bottom: 8px;
}

.demo-stat-number {
    font-size: 28px;
    font-weight: 800;
    color: var(--about-text-heading);
    line-height: 1.1;
    margin-bottom: 4px;
}

.demo-stat-label {
    font-size: 13px;
    color: var(--about-text-muted);
    font-weight: 500;
}

/* ──────────────────────────────────────────────────────────
   3. HERITAGE & CULTURE SECTION
   ────────────────────────────────────────────────────────── */
.demo-heritage-card {
    background: var(--about-bg-surface);
    border: 1px solid var(--about-border);
    border-left: 5px solid var(--about-gold-main);
    border-radius: 16px;
    padding: 32px 28px;
    margin-bottom: 40px;
    box-shadow: var(--about-card-shadow);
}

.demo-section-title {
    font-size: clamp(20px, 3vw, 25px);
    font-weight: 700;
    color: var(--about-text-heading);
    margin-bottom: 14px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.demo-heritage-content {
    display: grid;
    grid-template-columns: 1.4fr 1fr;
    gap: 28px;
    align-items: center;
}

@media (max-width: 860px) {
    .demo-heritage-content {
        grid-template-columns: 1fr;
    }
}

.demo-heritage-text p {
    font-size: 15.5px;
    line-height: 1.75;
    margin-bottom: 14px;
    color: var(--about-text-body);
}

.demo-heritage-text p:last-child {
    margin-bottom: 0;
}

.demo-heritage-box {
    background: var(--about-bg-subtle);
    border: 1px dashed var(--about-border-highlight);
    border-radius: 12px;
    padding: 20px;
}

.demo-heritage-box-title {
    font-size: 14px;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--about-gold-dark);
    margin-bottom: 10px;
    letter-spacing: 0.5px;
}

[data-theme="dark"] .demo-heritage-box-title {
    color: var(--about-gold-light);
}

.demo-heritage-timeline {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.demo-heritage-timeline li {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    font-size: 13.5px;
    line-height: 1.5;
}

.demo-heritage-timeline li i {
    color: var(--about-gold-main);
    margin-top: 3px;
}

/* ──────────────────────────────────────────────────────────
   4. CHESS QUOTE STUDIO
   ────────────────────────────────────────────────────────── */
.demo-quote-section {
    margin-bottom: 44px;
}

.demo-quote-studio {
    background: var(--about-bg-surface);
    border: 1px solid var(--about-border);
    border-radius: 18px;
    padding: 30px;
    box-shadow: var(--about-card-shadow);
    display: grid;
    grid-template-columns: 480px 1fr;
    gap: 36px;
    align-items: center;
}

@media (max-width: 1100px) {
    .demo-quote-studio {
        grid-template-columns: 420px 1fr;
        gap: 28px;
        padding: 24px;
    }
}

@media (max-width: 880px) {
    .demo-quote-studio {
        grid-template-columns: 1fr;
        padding: 20px;
        gap: 24px;
    }
    .demo-quote-visual-wrapper {
        max-width: 480px;
        width: 100%;
        margin: 0 auto;
    }
}

.demo-quote-visual-wrapper {
    position: relative;
    border-radius: 14px;
    overflow: hidden;
    background: #000000;
    box-shadow: 0 6px 18px rgba(0, 0, 0, 0.15);
    aspect-ratio: 1 / 1;
    display: flex;
    align-items: center;
    justify-content: center;
}

.demo-quote-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 14px;
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.demo-quote-details {
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.demo-quote-tag {
    font-size: 12.5px;
    font-weight: 700;
    color: var(--about-gold-main);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 6px;
}

.demo-quote-blockquote {
    font-size: clamp(17px, 2.2vw, 21px);
    font-style: italic;
    font-weight: 600;
    line-height: 1.55;
    color: var(--about-text-heading);
    margin: 0 0 12px;
    position: relative;
    border: none;
    padding: 0;
}

.demo-quote-author {
    font-size: 15px;
    font-weight: 700;
    color: var(--about-gold-dark);
    margin-bottom: 22px;
    display: flex;
    align-items: center;
    gap: 8px;
}

[data-theme="dark"] .demo-quote-author {
    color: var(--about-gold-light);
}

.demo-quote-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    align-items: center;
}

.demo-quote-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 9px 16px;
    border-radius: 10px;
    font-size: 13.5px;
    font-weight: 600;
    background: var(--about-bg-subtle);
    color: var(--about-text-heading) !important;
    border: 1px solid var(--about-border);
    cursor: pointer;
    text-decoration: none;
    transition: all 0.2s ease;
}

.demo-quote-btn:hover {
    background: var(--about-gold-main);
    color: #ffffff !important;
    border-color: var(--about-gold-main);
    transform: translateY(-1px);
}

.demo-quote-btn.copied {
    background: #16a34a !important;
    color: #ffffff !important;
    border-color: #16a34a !important;
}

/* ──────────────────────────────────────────────────────────
   5. FEATURE EXPLORATION CARDS GRID (3 Columns)
   ────────────────────────────────────────────────────────── */
.demo-features-section {
    margin-bottom: 44px;
}

.demo-section-header {
    text-align: center;
    max-width: 680px;
    margin: 0 auto 32px;
}

.demo-section-subtitle {
    font-size: 15px;
    color: var(--about-text-muted);
    line-height: 1.6;
}

.demo-features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 20px;
}

@media (max-width: 480px) {
    .demo-features-grid {
        grid-template-columns: 1fr;
    }
}

.demo-feature-card {
    background: var(--about-bg-surface);
    border: 1px solid var(--about-border);
    border-radius: 16px;
    padding: 24px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    box-shadow: var(--about-card-shadow);
    transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.demo-feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--about-card-hover-shadow);
    border-color: var(--about-border-highlight);
}

.demo-feature-top {
    margin-bottom: 18px;
}

.demo-feature-header-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 14px;
}

.demo-feature-icon-wrapper {
    width: 44px;
    height: 44px;
    border-radius: 12px;
    background: rgba(212, 175, 55, 0.12);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    color: var(--about-gold-main);
}

[data-theme="dark"] .demo-feature-icon-wrapper {
    background: rgba(251, 191, 36, 0.15);
    color: var(--about-gold-light);
}

.demo-feature-tag {
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    padding: 3px 10px;
    border-radius: 20px;
    background: var(--about-bg-subtle);
    border: 1px solid var(--about-border);
    color: var(--about-text-muted);
}

.demo-feature-title {
    font-size: 17.5px;
    font-weight: 700;
    color: var(--about-text-heading);
    margin-bottom: 8px;
    line-height: 1.3;
}

.demo-feature-desc {
    font-size: 14px;
    line-height: 1.65;
    color: var(--about-text-muted);
    margin: 0;
}

.demo-feature-action {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 13.5px;
    font-weight: 700;
    color: var(--about-gold-dark) !important;
    text-decoration: none;
    transition: gap 0.2s ease, color 0.2s ease;
    padding-top: 12px;
    border-top: 1px solid var(--about-border);
    width: 100%;
}

[data-theme="dark"] .demo-feature-action {
    color: var(--about-gold-light) !important;
}

.demo-feature-card:hover .demo-feature-action {
    gap: 10px;
}

/* ──────────────────────────────────────────────────────────
   6. TECH STACK SHOWCASE
   ────────────────────────────────────────────────────────── */
.demo-tech-section {
    background: var(--about-bg-surface);
    border: 1px solid var(--about-border);
    border-radius: 18px;
    padding: 28px;
    box-shadow: var(--about-card-shadow);
    margin-bottom: 44px;
}

.demo-tech-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 16px;
    margin-top: 20px;
}

.demo-tech-item {
    background: var(--about-bg-subtle);
    border: 1px solid var(--about-border);
    border-radius: 12px;
    padding: 16px;
    display: flex;
    align-items: flex-start;
    gap: 14px;
    transition: all 0.2s ease;
}

.demo-tech-item:hover {
    border-color: var(--about-border-highlight);
    background: var(--about-bg-elevated);
    transform: translateY(-2px);
}

.demo-tech-icon {
    font-size: 22px;
    color: var(--about-gold-main);
    margin-top: 2px;
}

.demo-tech-name {
    font-size: 14.5px;
    font-weight: 700;
    color: var(--about-text-heading);
    margin-bottom: 2px;
}

.demo-tech-detail {
    font-size: 12.5px;
    color: var(--about-text-muted);
    line-height: 1.4;
    margin: 0;
}

/* ──────────────────────────────────────────────────────────
   7. ACCORDION FAQ SECTION
   ────────────────────────────────────────────────────────── */
.demo-faq-section {
    margin-bottom: 44px;
}

.demo-faq-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.demo-faq-item {
    background: var(--about-bg-surface);
    border: 1px solid var(--about-border);
    border-radius: 12px;
    overflow: hidden;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.demo-faq-item[open] {
    border-color: var(--about-border-highlight);
    box-shadow: var(--about-card-shadow);
}

.demo-faq-summary {
    padding: 16px 20px;
    font-size: 15.5px;
    font-weight: 600;
    color: var(--about-text-heading);
    cursor: pointer;
    list-style: none;
    display: flex;
    align-items: center;
    justify-content: space-between;
    user-select: none;
    transition: background 0.2s ease;
}

.demo-faq-summary::-webkit-details-marker {
    display: none;
}

.demo-faq-summary:hover {
    background: var(--about-bg-subtle);
}

.demo-faq-summary i {
    color: var(--about-gold-main);
    font-size: 13px;
    transition: transform 0.25s ease;
}

.demo-faq-item[open] .demo-faq-summary i {
    transform: rotate(180deg);
}

.demo-faq-body {
    padding: 0 20px 18px;
    font-size: 14.5px;
    line-height: 1.7;
    color: var(--about-text-muted);
    border-top: 1px solid var(--about-border);
    padding-top: 14px;
}

/* ──────────────────────────────────────────────────────────
   8. GUIDING PRINCIPLES & CONTRIBUTION CTA
   ────────────────────────────────────────────────────────── */
.demo-principles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 18px;
    margin-bottom: 32px;
}

.demo-principle-card {
    background: var(--about-bg-surface);
    border: 1px solid var(--about-border);
    border-radius: 14px;
    padding: 20px;
    box-shadow: var(--about-card-shadow);
}

.demo-principle-title {
    font-size: 16px;
    font-weight: 700;
    color: var(--about-text-heading);
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.demo-principle-title i {
    color: var(--about-gold-main);
}

.demo-principle-desc {
    font-size: 13.5px;
    line-height: 1.6;
    color: var(--about-text-muted);
    margin: 0;
}

.demo-cta-card {
    background: linear-gradient(135deg, rgba(212, 175, 55, 0.15), rgba(15, 23, 42, 0.04));
    border: 1px solid var(--about-border-highlight);
    border-radius: 18px;
    padding: 32px;
    text-align: center;
    box-shadow: var(--about-card-shadow);
}

[data-theme="dark"] .demo-cta-card {
    background: linear-gradient(135deg, rgba(251, 191, 36, 0.1), rgba(15, 23, 42, 0.4));
}

.demo-cta-card h3 {
    font-size: 22px;
    font-weight: 800;
    color: var(--about-text-heading);
    margin-bottom: 10px;
}

.demo-cta-card p {
    font-size: 15px;
    color: var(--about-text-muted);
    max-width: 600px;
    margin: 0 auto 20px;
    line-height: 1.6;
}

.demo-cta-actions {
    display: flex;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
}