/**
 * 3DModelHub - Main Stylesheet
 * Production-grade dark theme design system
 */

/* ==========================================================================
   CSS Variables - Design Tokens
   ========================================================================== */
:root {
    /* Color Palette */
    --color-bg-primary: #0a0a0f;
    --color-bg-secondary: #111118;
    --color-bg-tertiary: #18181f;
    --color-bg-elevated: #1f1f28;
    --color-bg-hover: #26262f;
    --color-surface: #141419;
    --color-surface-light: #1c1c24;
    --color-surface-border: #2a2a35;
    --color-surface-border-light: #35353f;
    
    /* Brand */
    --color-primary: #6366f1;
    --color-primary-light: #818cf8;
    --color-primary-dark: #4f46e5;
    --color-primary-rgb: 99, 102, 241;
    --color-accent: #06b6d4;
    --color-accent-light: #22d3ee;
    --color-secondary: #8b5cf6;
    
    /* Text */
    --color-text-primary: #f8fafc;
    --color-text-secondary: #94a3b8;
    --color-text-tertiary: #64748b;
    --color-text-muted: #475569;
    
    /* Semantic */
    --color-success: #10b981;
    --color-success-light: #34d399;
    --color-warning: #f59e0b;
    --color-warning-light: #fbbf24;
    --color-error: #ef4444;
    --color-error-light: #f87171;
    --color-info: #3b82f6;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);
    --gradient-accent: linear-gradient(135deg, #06b6d4 0%, #3b82f6 100%);
    --gradient-hero: radial-gradient(ellipse 80% 50% at 50% -20%, rgba(99, 102, 241, 0.3), transparent 50%);
    --gradient-glow: radial-gradient(ellipse at center, rgba(99, 102, 241, 0.15) 0%, transparent 70%);
    
    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.2);
    --shadow-md: 0 4px 8px rgba(0,0,0,0.25);
    --shadow-lg: 0 8px 16px rgba(0,0,0,0.3);
    --shadow-xl: 0 16px 32px rgba(0,0,0,0.35);
    --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.4);
    --shadow-glow-sm: 0 0 20px rgba(99, 102, 241, 0.3);
    
    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    --text-xs: 0.75rem; --text-sm: 0.875rem; --text-base: 1rem;
    --text-lg: 1.125rem; --text-xl: 1.25rem; --text-2xl: 1.5rem;
    --text-3xl: 1.875rem; --text-4xl: 2.25rem; --text-5xl: 3rem; --text-6xl: 3.75rem;
    
    /* Spacing */
    --space-1: 0.25rem; --space-2: 0.5rem; --space-3: 0.75rem; --space-4: 1rem;
    --space-5: 1.25rem; --space-6: 1.5rem; --space-8: 2rem; --space-10: 2.5rem;
    --space-12: 3rem; --space-16: 4rem; --space-20: 5rem; --space-24: 6rem;
    
    /* Border Radius */
    --radius-sm: 0.375rem; --radius-md: 0.5rem; --radius-lg: 0.75rem;
    --radius-xl: 1rem; --radius-2xl: 1.25rem; --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Z-index */
    --z-dropdown: 100; --z-sticky: 200; --z-fixed: 300;
    --z-modal-backdrop: 400; --z-modal: 500; --z-toast: 600;
    
    /* Layout */
    --container-sm: 640px; --container-md: 768px; --container-lg: 1024px;
    --container-xl: 1280px; --container-2xl: 1440px;
    --header-height: 72px;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    font-size: var(--text-base);
    line-height: 1.6;
    color: var(--color-text-primary);
    background: var(--color-bg-primary);
    min-height: 100vh;
    overflow-x: hidden;
}

:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 2px; }
:focus:not(:focus-visible) { outline: none; }
::selection { background: var(--color-primary); color: white; }

a { color: var(--color-primary-light); text-decoration: none; transition: color var(--transition-fast); }
a:hover { color: var(--color-primary); }

img, video, svg { max-width: 100%; height: auto; display: block; }
ul, ol { list-style: none; }
table { border-collapse: collapse; width: 100%; }

button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; border: none; background: none; }

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-text-primary);
    letter-spacing: -0.02em;
}
h1 { font-size: var(--text-5xl); }
h2 { font-size: var(--text-4xl); }
h3 { font-size: var(--text-3xl); }
h4 { font-size: var(--text-2xl); }
h5 { font-size: var(--text-xl); }
h6 { font-size: var(--text-lg); }

p { color: var(--color-text-secondary); margin-bottom: var(--space-4); }
p:last-child { margin-bottom: 0; }

.text-gradient {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ==========================================================================
   Layout
   ========================================================================== */
.container {
    width: 100%;
    max-width: var(--container-xl);
    margin: 0 auto;
    padding: 0 var(--space-6);
}
.container-sm { max-width: var(--container-sm); }
.container-md { max-width: var(--container-md); }
.container-lg { max-width: var(--container-lg); }
.container-2xl { max-width: var(--container-2xl); }

.grid { display: grid; gap: var(--space-6); }
.grid-cols-1 { grid-template-columns: repeat(1, 1fr); }
.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }

.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-end { justify-content: flex-end; }
.flex-1 { flex: 1; }

.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }
.gap-10 { gap: var(--space-10); }
.gap-12 { gap: var(--space-12); }

/* ==========================================================================
   Navigation
   ========================================================================== */
.navbar {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: var(--z-fixed);
    height: var(--header-height);
    background: rgba(10, 10, 15, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid transparent;
    transition: all var(--transition-base);
}

.navbar.scrolled {
    background: rgba(10, 10, 15, 0.95);
    border-bottom-color: var(--color-surface-border);
    box-shadow: var(--shadow-lg);
}

.navbar-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
    max-width: var(--container-2xl);
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    font-size: var(--text-xl);
    font-weight: 700;
    color: var(--color-text-primary);
}
.navbar-brand:hover { color: var(--color-text-primary); opacity: 0.9; }

.navbar-logo {
    width: 40px; height: 40px;
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    box-shadow: var(--shadow-glow-sm);
}

.navbar-nav {
    display: flex;
    align-items: center;
    gap: var(--space-1);
}

.navbar-link {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-text-secondary);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}
.navbar-link:hover { color: var(--color-text-primary); background: var(--color-bg-hover); }
.navbar-link.active { color: var(--color-primary-light); background: rgba(99, 102, 241, 0.1); }

.navbar-actions { display: flex; align-items: center; gap: var(--space-3); }

.navbar-toggle {
    display: none;
    width: 44px; height: 44px;
    align-items: center;
    justify-content: center;
    color: var(--color-text-primary);
    border-radius: var(--radius-md);
}
.navbar-toggle:hover { background: var(--color-bg-hover); }

.navbar-toggle-icon {
    position: relative;
    width: 20px; height: 2px;
    background: currentColor;
    border-radius: 2px;
    transition: all var(--transition-fast);
}
.navbar-toggle-icon::before,
.navbar-toggle-icon::after {
    content: '';
    position: absolute;
    left: 0;
    width: 100%; height: 100%;
    background: currentColor;
    border-radius: 2px;
    transition: all var(--transition-fast);
}
.navbar-toggle-icon::before { top: -6px; }
.navbar-toggle-icon::after { bottom: -6px; }

.navbar-toggle[aria-expanded="true"] .navbar-toggle-icon { background: transparent; }
.navbar-toggle[aria-expanded="true"] .navbar-toggle-icon::before { top: 0; transform: rotate(45deg); }
.navbar-toggle[aria-expanded="true"] .navbar-toggle-icon::after { bottom: 0; transform: rotate(-45deg); }

/* User Menu */
.user-avatar {
    width: 40px; height: 40px;
    background: var(--gradient-accent);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--text-sm);
    font-weight: 600;
    color: white;
    cursor: pointer;
    border: 2px solid transparent;
    transition: all var(--transition-fast);
}
.user-avatar:hover { border-color: var(--color-primary); box-shadow: var(--shadow-glow-sm); }

/* ==========================================================================
   Buttons
   ========================================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    font-size: var(--text-sm);
    font-weight: 600;
    line-height: 1.5;
    white-space: nowrap;
    border: 1px solid transparent;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
}
.btn:disabled, .btn.disabled { opacity: 0.5; cursor: not-allowed; pointer-events: none; }

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md), 0 0 20px rgba(99, 102, 241, 0.3);
}
.btn-primary:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg), 0 0 30px rgba(99, 102, 241, 0.4);
}
.btn-primary:active:not(:disabled) { transform: translateY(0); }

.btn-secondary {
    background: var(--color-surface);
    color: var(--color-text-primary);
    border-color: var(--color-surface-border);
}
.btn-secondary:hover:not(:disabled) { background: var(--color-surface-light); border-color: var(--color-surface-border-light); }

.btn-ghost {
    background: transparent;
    color: var(--color-text-secondary);
}
.btn-ghost:hover:not(:disabled) { background: var(--color-bg-hover); color: var(--color-text-primary); }

.btn-outline {
    background: transparent;
    color: var(--color-primary-light);
    border-color: var(--color-primary);
}
.btn-outline:hover:not(:disabled) { background: var(--color-primary); color: white; }

.btn-danger { background: var(--color-error); color: white; }
.btn-danger:hover:not(:disabled) { background: var(--color-error-light); }

.btn-success { background: var(--color-success); color: white; }
.btn-success:hover:not(:disabled) { background: var(--color-success-light); }

.btn-sm { padding: var(--space-2) var(--space-4); font-size: var(--text-xs); }
.btn-lg { padding: var(--space-4) var(--space-8); font-size: var(--text-base); }
.btn-xl { padding: var(--space-5) var(--space-10); font-size: var(--text-lg); border-radius: var(--radius-xl); }

.btn-icon { padding: var(--space-3); width: 44px; height: 44px; }
.btn-icon.btn-sm { width: 36px; height: 36px; }

.btn-loading { position: relative; color: transparent !important; }
.btn-loading::after {
    content: '';
    position: absolute;
    width: 18px; height: 18px;
    border: 2px solid rgba(255,255,255,0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

/* ==========================================================================
   Forms
   ========================================================================== */
.form-group { margin-bottom: var(--space-5); }

.form-label {
    display: block;
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-text-primary);
    margin-bottom: var(--space-2);
}
.form-label.required::after { content: '*'; color: var(--color-error); margin-left: var(--space-1); }

.form-input,
.form-select,
.form-textarea {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    font-size: var(--text-base);
    color: var(--color-text-primary);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-surface-border);
    border-radius: var(--radius-lg);
    transition: all var(--transition-fast);
}
.form-input:hover, .form-select:hover, .form-textarea:hover { border-color: var(--color-surface-border-light); }
.form-input:focus, .form-select:focus, .form-textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}
.form-input::placeholder, .form-textarea::placeholder { color: var(--color-text-muted); }
.form-input.error, .form-select.error, .form-textarea.error { border-color: var(--color-error); }

.form-textarea { min-height: 120px; resize: vertical; }

.form-hint { display: block; font-size: var(--text-sm); color: var(--color-text-tertiary); margin-top: var(--space-2); }
.form-error { display: flex; align-items: center; gap: var(--space-1); font-size: var(--text-sm); color: var(--color-error); margin-top: var(--space-2); }

.form-check { display: flex; align-items: flex-start; gap: var(--space-3); cursor: pointer; }
.form-check-input { width: 20px; height: 20px; margin-top: 2px; accent-color: var(--color-primary); cursor: pointer; flex-shrink: 0; }
.form-check-label { font-size: var(--text-sm); color: var(--color-text-secondary); }

.input-group { display: flex; }
.input-group .form-input { border-top-right-radius: 0; border-bottom-right-radius: 0; }
.input-group .btn { border-top-left-radius: 0; border-bottom-left-radius: 0; margin-left: -1px; }

.input-icon-wrapper { position: relative; }
.input-icon-wrapper .form-input { padding-left: var(--space-12); }
.input-icon-wrapper .input-icon { position: absolute; left: var(--space-4); top: 50%; transform: translateY(-50%); color: var(--color-text-muted); pointer-events: none; }

/* ==========================================================================
   Cards
   ========================================================================== */
.card {
    background: var(--color-surface);
    border: 1px solid var(--color-surface-border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    transition: all var(--transition-base);
}
.card:hover { border-color: var(--color-surface-border-light); }

.card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4) var(--space-6);
    border-bottom: 1px solid var(--color-surface-border);
}
.card-title { font-size: var(--text-lg); font-weight: 600; color: var(--color-text-primary); }
.card-body { padding: var(--space-6); }
.card-footer { padding: var(--space-4) var(--space-6); border-top: 1px solid var(--color-surface-border); background: var(--color-bg-tertiary); }

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

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: calc(var(--header-height) + var(--space-16)) 0 var(--space-16);
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: -1;
}
.hero-bg::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--gradient-hero);
}
.hero-bg::after {
    content: '';
    position: absolute;
    bottom: 0; left: 0; right: 0;
    height: 50%;
    background: radial-gradient(ellipse 60% 40% at 80% 100%, rgba(6, 182, 212, 0.15), transparent);
}

.hero-grid {
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(rgba(99, 102, 241, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(99, 102, 241, 0.03) 1px, transparent 1px);
    background-size: 60px 60px;
    mask-image: radial-gradient(ellipse at center, black 20%, transparent 70%);
    -webkit-mask-image: radial-gradient(ellipse at center, black 20%, transparent 70%);
}

.hero-content { max-width: 800px; text-align: center; margin: 0 auto; }

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    background: var(--color-surface);
    border: 1px solid var(--color-surface-border);
    border-radius: var(--radius-full);
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-6);
}
.hero-badge-dot { width: 8px; height: 8px; background: var(--color-success); border-radius: 50%; animation: pulse 2s ease-in-out infinite; }

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.03em;
    margin-bottom: var(--space-6);
}

.hero-description {
    font-size: var(--text-xl);
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto var(--space-10);
    line-height: 1.7;
}

.hero-actions { display: flex; flex-wrap: wrap; gap: var(--space-4); justify-content: center; }

.hero-stats {
    display: flex;
    justify-content: center;
    gap: var(--space-12);
    margin-top: var(--space-16);
    padding-top: var(--space-8);
    border-top: 1px solid var(--color-surface-border);
}
.hero-stat { text-align: center; }
.hero-stat-value { font-size: var(--text-4xl); font-weight: 700; color: var(--color-text-primary); margin-bottom: var(--space-1); }
.hero-stat-label { font-size: var(--text-sm); color: var(--color-text-tertiary); }

/* ==========================================================================
   Section Styles
   ========================================================================== */
.section { padding: var(--space-24) 0; }

.section-header { text-align: center; max-width: 600px; margin: 0 auto var(--space-16); }
.section-label { display: inline-block; font-size: var(--text-sm); font-weight: 600; text-transform: uppercase; letter-spacing: 0.1em; color: var(--color-primary-light); margin-bottom: var(--space-4); }
.section-title { font-size: var(--text-4xl); margin-bottom: var(--space-4); }
.section-description { font-size: var(--text-lg); color: var(--color-text-secondary); }

.feature-card {
    padding: var(--space-8);
    background: var(--color-surface);
    border: 1px solid var(--color-surface-border);
    border-radius: var(--radius-xl);
    transition: all var(--transition-base);
}
.feature-card:hover { border-color: var(--color-primary); transform: translateY(-4px); box-shadow: var(--shadow-lg); }

.feature-icon {
    width: 56px; height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    font-size: 24px;
    margin-bottom: var(--space-5);
    box-shadow: var(--shadow-glow-sm);
}
.feature-title { font-size: var(--text-xl); font-weight: 600; margin-bottom: var(--space-3); }
.feature-description { color: var(--color-text-secondary); line-height: 1.7; margin-bottom: 0; }

/* ==========================================================================
   Model Cards
   ========================================================================== */
.model-card {
    display: block;
    text-decoration: none;
    color: inherit;
    background: var(--color-surface);
    border: 1px solid var(--color-surface-border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    transition: all var(--transition-base);
}
.model-card:hover { border-color: var(--color-primary); transform: translateY(-4px); box-shadow: var(--shadow-lg); color: inherit; }

.model-card-preview {
    position: relative;
    aspect-ratio: 16/10;
    background: var(--color-bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}
.model-card-preview::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--gradient-glow);
    opacity: 0;
    transition: opacity var(--transition-base);
}
.model-card:hover .model-card-preview::before { opacity: 1; }

.model-card-thumbnail { width: 100%; height: 100%; object-fit: cover; transition: transform var(--transition-slow); }
.model-card:hover .model-card-thumbnail { transform: scale(1.05); }

.model-card-placeholder { display: flex; align-items: center; justify-content: center; color: var(--color-text-muted); }

.model-card-badge {
    position: absolute;
    top: var(--space-3); right: var(--space-3);
    padding: var(--space-1) var(--space-3);
    background: var(--color-bg-primary);
    border: 1px solid var(--color-surface-border);
    border-radius: var(--radius-full);
    font-size: var(--text-xs);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-primary-light);
}

.model-card-info { padding: var(--space-4); }
.model-card-title {
    font-size: var(--text-base);
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--space-2);
    display: -webkit-box;
    -webkit-line-clamp: 1;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.model-card-title a { color: inherit; }
.model-card-title a:hover { color: var(--color-primary-light); }

.model-card-meta { display: flex; align-items: center; gap: var(--space-4); font-size: var(--text-sm); color: var(--color-text-tertiary); }
.model-card-author { display: flex; align-items: center; gap: var(--space-2); }
.model-card-author a { color: inherit; }
.model-card-author a:hover { color: var(--color-primary-light); }
.model-card-stat { display: flex; align-items: center; gap: var(--space-1); }

/* Avatar */
.avatar {
    width: 32px; height: 32px;
    border-radius: var(--radius-full);
    background: var(--gradient-accent);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--text-sm);
    font-weight: 600;
    color: white;
    flex-shrink: 0;
}
.avatar-xs { width: 20px; height: 20px; font-size: 10px; }
.avatar-sm { width: 28px; height: 28px; font-size: var(--text-xs); }
.avatar-lg { width: 48px; height: 48px; font-size: var(--text-lg); }
.avatar-xl { width: 64px; height: 64px; font-size: var(--text-xl); }

/* ==========================================================================
   Footer
   ========================================================================== */
.footer {
    background: var(--color-surface);
    border-top: 1px solid var(--color-surface-border);
    padding: var(--space-16) 0 var(--space-8);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr repeat(3, 1fr);
    gap: var(--space-12);
    margin-bottom: var(--space-12);
}

.footer-brand { max-width: 300px; }
.footer-logo { display: flex; align-items: center; gap: var(--space-3); font-size: var(--text-xl); font-weight: 700; color: var(--color-text-primary); margin-bottom: var(--space-4); }
.footer-description { font-size: var(--text-sm); color: var(--color-text-tertiary); line-height: 1.7; margin-bottom: var(--space-6); }

.footer-social { display: flex; gap: var(--space-3); }
.footer-social-link {
    width: 40px; height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-tertiary);
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}
.footer-social-link:hover { color: var(--color-primary-light); background: var(--color-bg-hover); }

.footer-heading { font-size: var(--text-sm); font-weight: 600; color: var(--color-text-primary); text-transform: uppercase; letter-spacing: 0.1em; margin-bottom: var(--space-5); }
.footer-links { display: flex; flex-direction: column; gap: var(--space-3); }
.footer-link { font-size: var(--text-sm); color: var(--color-text-tertiary); transition: color var(--transition-fast); }
.footer-link:hover { color: var(--color-primary-light); }

.footer-bottom { display: flex; justify-content: space-between; align-items: center; padding-top: var(--space-8); border-top: 1px solid var(--color-surface-border); }
.footer-copyright { font-size: var(--text-sm); color: var(--color-text-muted); }
.footer-legal { display: flex; gap: var(--space-6); }

/* ==========================================================================
   Modals
   ========================================================================== */
.dm-modal-overlay {
    display: none;
    position: fixed;
    inset: 0;
    z-index: var(--z-modal-backdrop);
    background: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(4px);
    align-items: center;
    justify-content: center;
    padding: var(--space-4);
    opacity: 0;
    transition: opacity var(--transition-base);
}
.dm-modal-overlay.dm-modal-visible { display: flex; opacity: 1; }

.modal {
    width: 100%;
    max-width: 500px;
    max-height: calc(100vh - var(--space-8));
    background: var(--color-surface);
    border: 1px solid var(--color-surface-border);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    transform: scale(0.95) translateY(20px);
    transition: transform var(--transition-base);
}
.dm-modal-overlay.dm-modal-visible .modal { transform: scale(1) translateY(0); }

.modal-lg { max-width: 700px; }
.modal-xl { max-width: 900px; }

.modal-header { display: flex; align-items: center; justify-content: space-between; padding: var(--space-5) var(--space-6); border-bottom: 1px solid var(--color-surface-border); }
.modal-title { font-size: var(--text-lg); font-weight: 600; }
.modal-close { width: 36px; height: 36px; display: flex; align-items: center; justify-content: center; color: var(--color-text-tertiary); border-radius: var(--radius-md); transition: all var(--transition-fast); }
.modal-close:hover { color: var(--color-text-primary); background: var(--color-bg-hover); }

.modal-body { padding: var(--space-6); overflow-y: auto; }
.modal-footer { display: flex; justify-content: flex-end; gap: var(--space-3); padding: var(--space-4) var(--space-6); border-top: 1px solid var(--color-surface-border); background: var(--color-bg-tertiary); }

/* ==========================================================================
   Toast Notifications
   ========================================================================== */
.toast-container {
    position: fixed;
    bottom: var(--space-6);
    right: var(--space-6);
    z-index: var(--z-toast);
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
    max-width: 400px;
    pointer-events: none;
}

.toast {
    display: flex;
    align-items: flex-start;
    gap: var(--space-3);
    padding: var(--space-4);
    background: var(--color-surface);
    border: 1px solid var(--color-surface-border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    pointer-events: all;
    transform: translateX(100%);
    opacity: 0;
    transition: all var(--transition-base);
}
.toast.visible { transform: translateX(0); opacity: 1; }

.toast-icon { flex-shrink: 0; width: 20px; height: 20px; }
.toast-success .toast-icon { color: var(--color-success); }
.toast-error .toast-icon { color: var(--color-error); }
.toast-warning .toast-icon { color: var(--color-warning); }
.toast-info .toast-icon { color: var(--color-info); }

.toast-content { flex: 1; min-width: 0; }
.toast-message { font-size: var(--text-sm); color: var(--color-text-primary); line-height: 1.5; }
.toast-close { flex-shrink: 0; padding: var(--space-1); color: var(--color-text-tertiary); border-radius: var(--radius-sm); transition: all var(--transition-fast); }
.toast-close:hover { color: var(--color-text-primary); background: var(--color-bg-hover); }

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

.dropdown-menu {
    position: absolute;
    top: 100%;
    right: 0;
    min-width: 200px;
    padding: var(--space-2);
    margin-top: var(--space-2);
    background: var(--color-surface);
    border: 1px solid var(--color-surface-border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all var(--transition-fast);
    z-index: var(--z-dropdown);
}
.dropdown-menu.open { opacity: 1; visibility: visible; transform: translateY(0); }

.dropdown-header { padding: var(--space-3) var(--space-4); border-bottom: 1px solid var(--color-surface-border); margin-bottom: var(--space-2); }
.dropdown-header-title { font-weight: 600; color: var(--color-text-primary); }
.dropdown-header-subtitle { font-size: var(--text-xs); color: var(--color-text-tertiary); }

.dropdown-item {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-2) var(--space-3);
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    cursor: pointer;
}
.dropdown-item:hover { background: var(--color-bg-hover); color: var(--color-text-primary); }
.dropdown-item.danger { color: var(--color-error); }
.dropdown-item.danger:hover { background: var(--color-error); background: rgba(239, 68, 68, 0.1); }

.dropdown-divider { height: 1px; margin: var(--space-2) 0; background: var(--color-surface-border); }

/* ==========================================================================
   Pagination
   ========================================================================== */
.pagination { display: flex; justify-content: center; align-items: center; gap: var(--space-2); }
.pagination-info { font-size: var(--text-sm); color: var(--color-text-tertiary); margin: 0 var(--space-4); }

/* ==========================================================================
   Badges
   ========================================================================== */
.badge {
    display: inline-flex;
    align-items: center;
    padding: var(--space-1) var(--space-2);
    font-size: var(--text-xs);
    font-weight: 600;
    border-radius: var(--radius-md);
}
.badge-primary { background: rgba(99, 102, 241, 0.1); color: var(--color-primary-light); }
.badge-success { background: rgba(16, 185, 129, 0.1); color: var(--color-success); }
.badge-warning { background: rgba(245, 158, 11, 0.1); color: var(--color-warning); }
.badge-error { background: rgba(239, 68, 68, 0.1); color: var(--color-error); }
.badge-info { background: rgba(59, 130, 246, 0.1); color: var(--color-info); }

/* ==========================================================================
   Empty State
   ========================================================================== */
.empty-state { text-align: center; padding: var(--space-16) var(--space-8); }
.empty-state-icon { width: 80px; height: 80px; margin: 0 auto var(--space-6); background: var(--color-surface); border-radius: var(--radius-xl); display: flex; align-items: center; justify-content: center; color: var(--color-text-muted); }
.empty-state-title { font-size: var(--text-xl); font-weight: 600; margin-bottom: var(--space-2); }
.empty-state-description { color: var(--color-text-secondary); margin-bottom: var(--space-6); }

/* ==========================================================================
   Animations
   ========================================================================== */
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.5; } }
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes fadeInUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
@keyframes skeleton { 0% { background-position: 200% 0; } 100% { background-position: -200% 0; } }

.animate-spin { animation: spin 1s linear infinite; }
.animate-pulse { animation: pulse 2s ease-in-out infinite; }
.animate-fade-in { animation: fadeIn 0.3s ease-out; }
.animate-fade-in-up { animation: fadeInUp 0.5s ease-out; }

[data-animate] { opacity: 0; transform: translateY(30px); transition: opacity 0.6s ease-out, transform 0.6s ease-out; }
[data-animate].animated { opacity: 1; transform: translateY(0); }

.skeleton { background: linear-gradient(90deg, var(--color-surface) 25%, var(--color-surface-light) 50%, var(--color-surface) 75%); background-size: 200% 100%; animation: skeleton 1.5s ease-in-out infinite; border-radius: var(--radius-md); }

.spinner { width: 20px; height: 20px; border: 2px solid var(--color-surface-border); border-top-color: var(--color-primary); border-radius: 50%; animation: spin 0.6s linear infinite; }
.spinner-sm { width: 16px; height: 16px; }
.spinner-lg { width: 32px; height: 32px; border-width: 3px; }

/* ==========================================================================
   Utilities
   ========================================================================== */
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.hidden { display: none !important; }
.invisible { visibility: hidden; }

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

.text-primary { color: var(--color-text-primary) !important; }
.text-secondary { color: var(--color-text-secondary) !important; }
.text-tertiary { color: var(--color-text-tertiary) !important; }
.text-muted { color: var(--color-text-muted) !important; }
.text-success { color: var(--color-success) !important; }
.text-warning { color: var(--color-warning) !important; }
.text-error { color: var(--color-error) !important; }

.bg-surface { background-color: var(--color-surface); }
.bg-elevated { background-color: var(--color-bg-elevated); }

.rounded { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }
.rounded-full { border-radius: var(--radius-full); }

.shadow { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-xl { box-shadow: var(--shadow-xl); }

.w-full { width: 100%; }
.h-full { height: 100%; }
.min-h-screen { min-height: 100vh; }

.relative { position: relative; }
.absolute { position: absolute; }
.fixed { position: fixed; }
.sticky { position: sticky; }

.overflow-hidden { overflow: hidden; }
.overflow-auto { overflow: auto; }

.cursor-pointer { cursor: pointer; }
.select-none { user-select: none; }

.transition { transition: all var(--transition-base); }
.transition-fast { transition: all var(--transition-fast); }

/* Spacing utilities */
.m-0 { margin: 0; }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }
.mx-auto { margin-left: auto; margin-right: auto; }

.p-0 { padding: 0; }
.p-4 { padding: var(--space-4); }
.p-6 { padding: var(--space-6); }
.p-8 { padding: var(--space-8); }

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 1024px) {
    .grid-cols-4 { grid-template-columns: repeat(2, 1fr); }
    .grid-cols-3 { grid-template-columns: repeat(2, 1fr); }
    .hero-stats { gap: var(--space-8); }
    .footer-grid { grid-template-columns: repeat(2, 1fr); }
    .hide-tablet { display: none !important; }
}

@media (max-width: 768px) {
    :root { --header-height: 64px; }
    .container { padding: 0 var(--space-4); }
    
    .navbar-toggle { display: flex; }
    .navbar-nav {
        position: fixed;
        top: var(--header-height);
        left: 0; right: 0; bottom: 0;
        flex-direction: column;
        background: var(--color-bg-primary);
        padding: var(--space-4);
        gap: var(--space-1);
        transform: translateX(-100%);
        transition: transform var(--transition-slow);
        overflow-y: auto;
    }
    .navbar-nav.open { transform: translateX(0); }
    .navbar-link { width: 100%; padding: var(--space-4); font-size: var(--text-base); justify-content: flex-start; }
    
    .grid-cols-4, .grid-cols-3, .grid-cols-2 { grid-template-columns: 1fr; }
    .hero { padding-top: calc(var(--header-height) + var(--space-8)); min-height: auto; }
    .hero-title { font-size: var(--text-4xl); }
    .hero-description { font-size: var(--text-lg); }
    .hero-stats { flex-direction: column; gap: var(--space-6); }
    
    .section { padding: var(--space-16) 0; }
    .section-title { font-size: var(--text-3xl); }
    
    .footer-grid { grid-template-columns: 1fr; gap: var(--space-8); }
    .footer-bottom { flex-direction: column; gap: var(--space-4); text-align: center; }
    .footer-legal { justify-content: center; }
    
    .toast-container { left: var(--space-4); right: var(--space-4); bottom: var(--space-4); max-width: none; }
    .modal { margin: var(--space-4); }
    
    .hide-mobile { display: none !important; }
}

@media (max-width: 480px) {
    .hero-actions { flex-direction: column; width: 100%; }
    .hero-actions .btn { width: 100%; }
    .btn-xl { padding: var(--space-4) var(--space-6); font-size: var(--text-base); }
}

@media (min-width: 769px) { .show-mobile { display: none !important; } }

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; }
    html { scroll-behavior: auto; }
}

/* ============================================================
   LAYOUT DENSITY
   ============================================================ */

/* Comfortable (default) */
[data-density="comfortable"] {
    --density-spacing-xs: 0.5rem;
    --density-spacing-sm: 0.75rem;
    --density-spacing-md: 1rem;
    --density-spacing-lg: 1.5rem;
    --density-spacing-xl: 2rem;
    --density-padding: 1.25rem;
    --density-gap: 1.5rem;
    --density-card-padding: 1.5rem;
}

/* Compact */
[data-density="compact"] {
    --density-spacing-xs: 0.25rem;
    --density-spacing-sm: 0.5rem;
    --density-spacing-md: 0.75rem;
    --density-spacing-lg: 1rem;
    --density-spacing-xl: 1.25rem;
    --density-padding: 0.875rem;
    --density-gap: 1rem;
    --density-card-padding: 1rem;
}

/* Apply density to common elements */
[data-density="compact"] .container {
    padding-left: var(--density-padding);
    padding-right: var(--density-padding);
}

[data-density="compact"] .section {
    padding-top: var(--spacing-12);
    padding-bottom: var(--spacing-12);
}

[data-density="compact"] .card {
    padding: var(--density-card-padding);
}

[data-density="compact"] .navbar-inner {
    padding: var(--density-spacing-sm) var(--density-padding);
}

[data-density="compact"] .hero {
    padding: var(--spacing-16) 0;
}

[data-density="compact"] .hero-content {
    gap: var(--density-gap);
}

[data-density="compact"] .features-grid {
    gap: var(--density-gap);
}

[data-density="compact"] .footer {
    padding: var(--spacing-10) 0 var(--spacing-6);
}

[data-density="compact"] .footer-grid {
    gap: var(--density-gap);
}

[data-density="compact"] .btn {
    padding: 0.5rem 1rem;
}

[data-density="compact"] .btn-xl {
    padding: 0.75rem 1.5rem;
}

/* ============================================================
   TOAST NOTIFICATIONS
   ============================================================ */

.toast-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 9999;
    display: flex;
    flex-direction: column;
    gap: 10px;
    max-width: 400px;
    pointer-events: none;
}

.toast {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 14px 16px;
    background: var(--color-surface);
    border: 1px solid var(--color-surface-border);
    border-radius: var(--radius-lg);
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
    pointer-events: auto;
    opacity: 0;
    transform: translateX(100%);
    transition: opacity 0.2s, transform 0.2s;
    position: relative;
    overflow: hidden;
}

.toast-show {
    opacity: 1;
    transform: translateX(0);
}

.toast-hide {
    animation: toast-slide-out 0.2s ease forwards;
}

@keyframes toast-slide-out {
    to { opacity: 0; transform: translateX(100%); }
}

.toast-icon {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.toast-message {
    flex: 1;
    font-size: 14px;
    line-height: 1.5;
    color: var(--color-text);
}

.toast-close {
    flex-shrink: 0;
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: none;
    color: var(--color-text-muted);
    font-size: 20px;
    cursor: pointer;
    border-radius: 4px;
    transition: background 0.15s, color 0.15s;
    margin: -4px -6px -4px 0;
}

.toast-close:hover {
    background: var(--color-surface-hover);
    color: var(--color-text);
}

.toast-progress {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: rgba(0,0,0,0.1);
}

.toast-progress-bar {
    height: 100%;
    width: 100%;
    background: currentColor;
    opacity: 0.3;
}

/* Toast types */
.toast-success { border-left: 4px solid var(--color-success); }
.toast-success .toast-icon { color: var(--color-success); }

.toast-error { border-left: 4px solid var(--color-error); }
.toast-error .toast-icon { color: var(--color-error); }

.toast-warning { border-left: 4px solid var(--color-warning); }
.toast-warning .toast-icon { color: var(--color-warning); }

.toast-info { border-left: 4px solid var(--color-primary); }
.toast-info .toast-icon { color: var(--color-primary); }

@media (max-width: 480px) {
    .toast-container {
        left: 10px;
        right: 10px;
        max-width: none;
    }
}