/* Guns, Germs, and Steel - Landing Page */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #8B4513;
    --primary-light: #A0522D;
    --accent: #4169E1;
    --accent-light: #87CEEB;
    --success: #228B22;
    --warning: #DAA520;
    --bg: #f9f7f4;
    --text: #2c3e50;
    --text-light: #666;
    --border: #ddd;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.15);
}

/* Soft Sepia Theme - Easy on Eyes */
:root[data-theme="soft-sepia"] {
    --primary: #6B5B47;
    --primary-light: #8B7B67;
    --accent: #5D7399;
    --accent-light: #A8B8D8;
    --success: #4A7C59;
    --warning: #B8860B;
    --bg: #F5F1E8;
    --text: #3A3A3A;
    --text-light: #7A7A7A;
    --border: #C8B8A8;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.12);
}

/* Classic Sepia Theme - True Sepia Tone */
:root[data-theme="sepia"] {
    --primary: #7B5E38;
    --primary-light: #9B7E58;
    --accent: #6B5D4D;
    --accent-light: #A89C8C;
    --success: #5A7C59;
    --warning: #B8860B;
    --bg: #F4ECD8;
    --text: #4A3A2A;
    --text-light: #8A7A6A;
    --border: #B8A898;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.15);
}

/* Tokyo Night Dark Theme - Deep Blue/Purple Dark Theme */
:root[data-theme="dark"] {
    --primary: #4169E1;
    --primary-light: #5D8BDD;
    --accent: #BB9AF7;
    --accent-light: #C084FC;
    --success: #4FD18B;
    --warning: #F7B868;
    --bg: #1A1B26;
    --text: #C0CAF5;
    --text-light: #7AA2F7;
    --border: #2E3440;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.4);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: Georgia, 'Times New Roman', serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
}

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

a {
    color: var(--accent);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* ===== THEME TOGGLE ===== */

.theme-toggle-container {
    position: absolute;
    top: 20px;
    right: 20px;
    z-index: 1000;
}

.theme-toggle-btn {
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: white;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    font-size: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}

/* ===== HERO SECTION ===== */

.hero {
    background: linear-gradient(135deg, #8B4513 0%, #654321 100%);
    color: white;
    padding: 80px 20px;
    text-align: center;
    margin-bottom: 60px;
    position: relative;
    overflow: hidden;
}

.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: 50px 50px;
    pointer-events: none;
}

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

.hero-title {
    font-size: 56px;
    font-weight: bold;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
    font-size: 32px;
    font-weight: 300;
    margin-bottom: 10px;
    opacity: 0.95;
}

.hero-author {
    font-size: 18px;
    margin-bottom: 20px;
    opacity: 0.85;
}

.hero-metadata {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-bottom: 30px;
    font-size: 14px;
    opacity: 0.9;
    flex-wrap: wrap;
}

.hero-cta {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

/* ===== BUTTONS ===== */

.btn {
    display: inline-block;
    padding: 14px 28px;
    border-radius: 6px;
    font-family: system-ui, -apple-system, sans-serif;
    font-size: 15px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
}

.btn-primary {
    background: var(--accent);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: var(--bg);
    color: var(--primary);
    border: 2px solid var(--border);
}

.btn-secondary:hover {
    background: transparent;
    color: white;
    transform: translateY(-2px);
}

.btn-small {
    padding: 10px 20px;
    font-size: 13px;
}

/* ===== OVERVIEW SECTION ===== */

.overview {
    padding: 60px 0;
    margin-bottom: 60px;
}

.overview h2 {
    text-align: center;
    font-size: 36px;
    margin-bottom: 30px;
    color: var(--primary);
}

.overview-text {
    text-align: center;
    font-size: 18px;
    max-width: 800px;
    margin: 0 auto 40px;
    color: var(--text-light);
    line-height: 1.8;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.feature {
    background: var(--bg);
    padding: 30px;
    border-radius: 8px;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
    text-align: center;
    transition: all 0.3s ease;
}

.feature:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    font-size: 48px;
    display: block;
    margin-bottom: 15px;
}

.feature h3 {
    font-size: 18px;
    margin-bottom: 10px;
    color: var(--primary);
}

.feature p {
    font-size: 14px;
    color: var(--text-light);
}

/* ===== TOC SECTION ===== */

.toc-section {
    padding: 60px 0;
    margin-bottom: 60px;
    background: var(--bg);
    border-radius: 8px;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.toc-section h2 {
    text-align: center;
    font-size: 36px;
    margin-bottom: 50px;
    color: var(--primary);
    padding-top: 60px;
}

.toc-group {
    margin-bottom: 40px;
}

.toc-group h3 {
    font-size: 20px;
    color: var(--primary);
    margin-bottom: 20px;
    padding-left: 20px;
    border-left: 4px solid var(--accent);
}

.toc-item {
    background: #fafafa;
    padding: 20px;
    margin-bottom: 12px;
    border-radius: 6px;
    border-left: 3px solid var(--primary);
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.toc-item:hover {
    background: var(--bg);
    box-shadow: var(--shadow);
    transform: translateX(4px);
}

.toc-label,
.toc-item strong {
    font-size: 16px;
    color: var(--text);
    font-weight: 600;
}

.toc-subtitle {
    font-size: 14px;
    color: var(--text-light);
    font-style: italic;
}

.toc-pages {
    font-size: 13px;
    color: var(--primary);
    font-weight: bold;
}

.toc-themes {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.theme {
    display: inline-block;
    background: var(--accent-light);
    color: var(--primary);
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 12px;
    font-family: system-ui, -apple-system, sans-serif;
    font-weight: 600;
}

/* ===== THEMES SECTION ===== */

.themes-section {
    padding: 60px 0;
    margin-bottom: 60px;
}

.themes-section h2 {
    text-align: center;
    font-size: 36px;
    margin-bottom: 50px;
    color: var(--primary);
}

.themes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
}

.theme-card {
    background: var(--bg);
    padding: 30px;
    border-radius: 8px;
    box-shadow: var(--shadow);
    text-align: center;
    border: 1px solid var(--border);
    transition: all 0.3s ease;
}

.theme-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.theme-icon {
    font-size: 48px;
    margin-bottom: 15px;
    display: block;
}

.theme-card h3 {
    font-size: 18px;
    margin-bottom: 10px;
    color: var(--primary);
}

.theme-card p {
    font-size: 14px;
    color: var(--text-light);
}

/* ===== SIMULATORS SECTION ===== */

.simulators-section {
    padding: 60px 0;
    margin-bottom: 60px;
    background: linear-gradient(135deg, rgba(139, 69, 19, 0.05) 0%, rgba(65, 105, 225, 0.05) 100%);
    border-radius: 8px;
}

.simulators-section h2 {
    text-align: center;
    font-size: 36px;
    margin-bottom: 15px;
    color: var(--primary);
}

.section-intro {
    text-align: center;
    font-size: 16px;
    color: var(--text-light);
    margin-bottom: 40px;
}

.simulators-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
}

.simulator-card {
    background: var(--bg);
    padding: 35px;
    border-radius: 8px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    text-align: center;
    transition: all 0.3s ease;
}

.simulator-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.simulator-icon {
    font-size: 56px;
    margin-bottom: 15px;
    display: block;
}

.simulator-card h3 {
    font-size: 20px;
    margin-bottom: 12px;
    color: var(--primary);
}

.simulator-card p {
    font-size: 14px;
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.6;
}

/* ===== FOOTER ===== */

.footer {
    background: var(--primary);
    color: white;
    padding: 40px 0;
    text-align: center;
    border-top: 2px solid var(--primary-light);
}

.footer p {
    margin: 5px 0;
}

/* ===== RESPONSIVE ===== */

@media (max-width: 768px) {
    .hero-title {
        font-size: 36px;
    }

    .hero-subtitle {
        font-size: 22px;
    }

    .hero-metadata {
        gap: 15px;
        font-size: 12px;
    }

    .hero-cta {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        max-width: 300px;
    }

    .overview h2,
    .themes-section h2,
    .toc-section h2,
    .simulators-section h2 {
        font-size: 28px;
    }

    .features,
    .themes-grid,
    .simulators-grid {
        grid-template-columns: 1fr;
    }
}

/* ===== ANIMATIONS ===== */

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.feature,
.theme-card,
.simulator-card,
.toc-item {
    animation: fadeInUp 0.5s ease forwards;
}

.feature:nth-child(1) { animation-delay: 0.1s; }
.feature:nth-child(2) { animation-delay: 0.2s; }
.feature:nth-child(3) { animation-delay: 0.3s; }