/* =====================================================
   Typography Lab — Main Styles
   ===================================================== */

:root {
    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-display: 'Playfair Display', Georgia, serif;
    
    /* Scale */
    --base-size: 16px;
    --scale-display: 3.5rem;
    --scale-h1: 2.5rem;
    --scale-h2: 2rem;
    --scale-h3: 1.5rem;
    --scale-h4: 1.25rem;
    --scale-body: 1rem;
    --scale-small: 0.875rem;
    --scale-xs: 0.75rem;
    
    /* Colors - Light Mode */
    --bg: #ffffff;
    --bg-secondary: #f8fafc;
    --text: #0f172a;
    --text-secondary: #64748b;
    --border: #e2e8f0;
    --accent: #6366f1;
    --accent-hover: #4f46e5;
    --accent-light: #e0e7ff;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -2px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -4px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.1);
    
    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;
}

/* Dark Mode */
.dark-mode {
    --bg: #0f172a;
    --bg-secondary: #1e293b;
    --text: #f1f5f9;
    --text-secondary: #94a3b8;
    --border: #334155;
    --accent: #818cf8;
    --accent-hover: #a5b4fc;
    --accent-light: #312e81;
}

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

html {
    font-size: var(--base-size);
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    font-size: var(--scale-body);
    line-height: 1.6;
    color: var(--text);
    background: var(--bg);
    transition: background var(--transition-base), color var(--transition-base);
    min-height: 100vh;
}

/* =====================================================
   Header
   ===================================================== */

.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-sm);
    backdrop-filter: blur(12px);
    background: rgba(255,255,255,0.9);
}

.dark-mode .header {
    background: rgba(15,23,42,0.9);
}

.header-content {
    max-width: 1600px;
    margin: 0 auto;
    padding: var(--space-md) var(--space-xl);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-lg);
    flex-wrap: wrap;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-weight: 700;
    font-size: 1.25rem;
}

.logo-icon { font-size: 1.5rem; }

.logo-badge {
    background: linear-gradient(135deg, var(--accent), #8b5cf6);
    color: white;
    padding: 2px 8px;
    border-radius: var(--radius-full);
    font-size: var(--scale-xs);
    font-weight: 600;
}

.controls {
    display: flex;
    gap: var(--space-md);
    flex-wrap: wrap;
    align-items: flex-end;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.control-group label {
    font-size: var(--scale-xs);
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.control-group select,
.control-group input {
    padding: var(--space-sm) var(--space-md);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    background: var(--bg);
    color: var(--text);
    font-size: var(--scale-small);
    min-width: 120px;
    cursor: pointer;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.control-group select:hover,
.control-group input:hover {
    border-color: var(--accent);
}

.control-group select:focus,
.control-group input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-light);
}

.seed-input { width: 80px; }

.actions {
    display: flex;
    gap: var(--space-sm);
    align-items: center;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    font-size: var(--scale-small);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent), #8b5cf6);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text);
    border-color: var(--border);
}

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

.btn-outline {
    background: transparent;
    color: var(--text);
    border-color: var(--border);
}

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

.btn-icon {
    padding: var(--space-sm);
    background: var(--bg-secondary);
    border: 1px solid var(--border);
}

.btn-sm {
    padding: var(--space-xs) var(--space-sm);
    font-size: var(--scale-xs);
}

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

/* Dropdown */
.dropdown { position: relative; }

.dropdown-menu {
    position: absolute;
    top: 100%;
    right: 0;
    margin-top: var(--space-xs);
    min-width: 200px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition-fast);
    z-index: 50;
}

.dropdown.open .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-item {
    display: block;
    width: 100%;
    padding: var(--space-sm) var(--space-md);
    border: none;
    background: none;
    color: var(--text);
    text-align: left;
    font-size: var(--scale-small);
    cursor: pointer;
    transition: background var(--transition-fast);
}

.dropdown-item:hover {
    background: var(--accent-light);
}

.dropdown-divider {
    height: 1px;
    background: var(--border);
    margin: var(--space-sm) 0;
}

.dropdown-radio {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-xs) var(--space-md);
    font-size: var(--scale-small);
    cursor: pointer;
}

/* Custom Font Bar */
.custom-font-bar {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-md);
    padding: var(--space-sm) var(--space-xl);
    background: linear-gradient(135deg, var(--accent-light), #fef3c7);
    border-top: 1px solid var(--border);
    font-size: var(--scale-small);
}

.custom-font-bar.hidden { display: none; }

/* =====================================================
   Hero
   ===================================================== */

.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
    color: white;
    padding: var(--space-2xl) var(--space-xl);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.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");
    opacity: 0.5;
}

.hero-title {
    font-family: var(--font-display);
    font-size: clamp(2rem, 5vw, var(--scale-display));
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: var(--space-md);
    position: relative;
    text-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

.hero-subtitle {
    font-size: var(--scale-h4);
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto var(--space-lg);
    position: relative;
}

.hero-meta {
    display: flex;
    justify-content: center;
    gap: var(--space-xl);
    font-size: var(--scale-small);
    opacity: 0.8;
    position: relative;
}

/* =====================================================
   Container & Sections
   ===================================================== */

.container {
    max-width: 1600px;
    margin: 0 auto;
    padding: var(--space-xl);
}

.section {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    margin-bottom: var(--space-xl);
}

.section-title {
    font-size: var(--scale-h2);
    font-weight: 700;
    margin-bottom: var(--space-md);
    color: var(--text);
}

.section-description {
    color: var(--text-secondary);
    margin-bottom: var(--space-lg);
}

/* =====================================================
   Footer
   ===================================================== */

.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    padding: var(--space-xl);
    text-align: center;
    color: var(--text-secondary);
    font-size: var(--scale-small);
}

/* =====================================================
   Utilities
   ===================================================== */

.hidden { display: none !important; }

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

/* =====================================================
   Responsive
   ===================================================== */

@media (max-width: 1024px) {
    .header-content {
        flex-direction: column;
        align-items: stretch;
    }
    
    .controls, .actions {
        justify-content: center;
    }
}

@media (max-width: 640px) {
    .controls {
        flex-direction: column;
        align-items: stretch;
    }
    
    .control-group select,
    .control-group input {
        width: 100%;
    }
    
    .actions {
        flex-wrap: wrap;
    }
    
    .hero {
        padding: var(--space-xl) var(--space-md);
    }
    
    .container {
        padding: var(--space-md);
    }
}