/* ============================================
   DDD Book Website - Main Styles
   Monochromatic Theme
   ============================================ */

/* CSS Custom Properties */
:root {
    /* Monochromatic Colors */
    --color-primary: #141418;
    --color-secondary: #1a1a1f;
    --color-accent: #c2a070;
    --color-accent-light: #e3c89a;
    --color-gold: #d1b182;
    --color-gold-light: #ead9bc;
    --color-text: #e0e0e0;
    --color-text-muted: #777;
    --color-bg: #0c0c0e;
    --color-surface: #17171b;
    --color-surface-light: #222228;
    --color-border: rgba(255,255,255,0.08);
    
    /* Monochromatic chapter colors */
    --color-chapter: #888;
    --color-interjection: #666;
    --color-front-matter: #555;
    
    /* Typography */
    --font-display: 'Cinzel', serif;
    --font-body: 'Crimson Text', Georgia, serif;
    --font-ui: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-xxl: 3rem;
    
    /* Sizing */
    --max-width: 1200px;
    --max-width-content: 800px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 300ms ease;
    --transition-slow: 500ms ease;
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.2);
    --shadow-md: 0 6px 16px rgba(0,0,0,0.35);
    --shadow-lg: 0 8px 30px rgba(0,0,0,0.4);
    --shadow-glow: 0 0 24px rgba(194,160,112,0.15);
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 6px;
    --radius-lg: 12px;
    --radius-xl: 20px;
}

/* Light Theme */
[data-theme="light"] {
    --color-primary: #f5f5f5;
    --color-secondary: #e8e8e8;
    --color-text: #1a1a2e;
    --color-text-muted: #666;
    --color-bg: #ffffff;
    --color-surface: #f8f8f8;
    --color-surface-light: #fff;
    --color-border: rgba(0,0,0,0.1);
}

/* Reset & Base */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    font-size: 1.125rem;
    line-height: 1.7;
    color: var(--color-text);
    background:
        radial-gradient(1200px 800px at 10% -10%, rgba(194,160,112,0.08), transparent 60%),
        radial-gradient(900px 700px at 90% 10%, rgba(120,150,140,0.08), transparent 55%),
        var(--color-bg);
    min-height: 100vh;
    color-scheme: dark;
    -webkit-tap-highlight-color: transparent;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: var(--spacing-md);
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 4vw, 2.5rem); }
h3 { font-size: clamp(1.25rem, 3vw, 1.75rem); }
h4 { font-size: 1.25rem; }

p {
    margin-bottom: var(--spacing-md);
}

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

a:hover {
    color: var(--color-accent-light);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    font-family: var(--font-ui);
    font-size: 1rem;
    font-weight: 500;
    min-height: 44px;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-normal);
    text-decoration: none;
    touch-action: manipulation;
    user-select: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-accent), var(--color-accent-light));
    color: white;
    box-shadow: var(--shadow-md), var(--shadow-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg), 0 0 28px rgba(194,160,112,0.45);
}

.btn-secondary {
    background: var(--color-surface-light);
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover {
    background: var(--color-surface);
    border-color: var(--color-accent);
}

.btn-outline {
    background: transparent;
    color: var(--color-accent);
    border: 2px solid var(--color-accent);
}

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

.btn-icon {
    padding: var(--spacing-sm);
    background: var(--color-surface);
    border-radius: var(--radius-sm);
}

.btn-icon:hover {
    background: var(--color-surface-light);
}

/* Section Headers */
.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.section-header h2 {
    color: var(--color-gold);
}

.divider {
    width: 80px;
    height: 3px;
    background: linear-gradient(90deg, transparent, var(--color-gold), transparent);
    margin: var(--spacing-md) auto 0;
}

/* Cards */
.card {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    border: 1px solid var(--color-border);
    transition: all var(--transition-normal);
}

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

/* Footer */
.site-footer {
    background: var(--color-surface);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-xl) var(--spacing-lg);
    text-align: center;
}

.footer-content {
    max-width: var(--max-width);
    margin: 0 auto;
}

.footer-note {
    color: var(--color-text-muted);
    font-size: 0.875rem;
    margin-top: var(--spacing-sm);
}

/* Utilities */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.text-center { text-align: center; }
.text-muted { color: var(--color-text-muted); }

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--color-surface);
}

::-webkit-scrollbar-thumb {
    background: var(--color-accent);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-accent-light);
}

/* Selection */
::selection {
    background: var(--color-accent);
    color: white;
}

/* Focus States */
:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

@media (pointer: coarse) {
    .btn,
    .btn-icon {
        min-height: 48px;
    }
}

/* Media Queries */
@media (max-width: 768px) {
    html {
        font-size: 14px;
    }
    
    .container {
        padding: 0 var(--spacing-md);
    }
}