/*
Theme Name: AI Platform
Theme URI: https://aifatiao.com
Description: AI 综合平台主题 - 苹果风格极简设计
Author: SuperFaTiao
Template: onenav
Version: 3.0
License: GPL v2 or later
*/

/* ============================================
   AI Platform Design System v3.0
   苹果风格 · 极简优雅 · 专业高端
   ============================================ */

:root {
    --transition-smooth: cubic-bezier(0.25, 0.46, 0.45, 0.94);
    --transition-bounce: cubic-bezier(0.34, 1.56, 0.64, 1);
    --transition-spring: cubic-bezier(0.175, 0.885, 0.32, 1.275);

    --font-serif: 'Noto Serif SC', 'Cormorant Garamond', Georgia, serif;
    --font-sans: 'Outfit', -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', sans-serif;
    --font-mono: 'SF Mono', 'Fira Code', 'Consolas', 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: 2rem;
    --text-4xl: 2.5rem;
    --text-5xl: 3.5rem;

    --font-light: 300;
    --font-normal: 400;
    --font-medium: 500;
    --font-semibold: 600;
    --font-bold: 700;

    --leading-tight: 1.2;
    --leading-snug: 1.4;
    --leading-normal: 1.6;
    --leading-relaxed: 1.8;

    --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;
    --space-32: 8rem;

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-2xl: 24px;
    --radius-full: 9999px;

    --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.08);
    --shadow-xl: 0 16px 60px rgba(0, 0, 0, 0.1);
    --shadow-2xl: 0 25px 80px rgba(0, 0, 0, 0.15);

    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal: 400;
    --z-tooltip: 500;

    --header-height: 80px;
    --hero-height: auto;
    --footer-height: auto;
}

[data-theme="light"],
:root {
    --bg-primary: #F8F9FA;
    --bg-secondary: #F1F3F5;
    --bg-tertiary: #E9ECEF;
    --bg-card: #FFFFFF;
    --bg-hover: rgba(0, 0, 0, 0.04);

    --text-primary: #212529;
    --text-secondary: #495057;
    --text-tertiary: #6C757D;
    --text-muted: #ADB5BD;
    --text-light: #DEE2E6;

    --border-light: rgba(0, 0, 0, 0.06);
    --border-default: rgba(0, 0, 0, 0.1);
    --border-strong: rgba(0, 0, 0, 0.15);

    --accent: #6366F1;
    --accent-light: #818CF8;
    --accent-muted: #A5B4FC;
    --accent-dark: #4F46E5;

    --primary: #6366F1;
    --primary-light: #818CF8;
    --primary-muted: #C7D2FE;

    --secondary: #EC4899;
    --secondary-light: #F472B6;

    --success: #10B981;
    --success-light: #34D399;
    --warning: #F59E0B;
    --warning-light: #FBBF24;
    --error: #EF4444;
    --error-light: #F87171;
    --info: #3B82F6;
    --info-light: #60A5FA;
}

[data-theme="dark"] {
    --bg-primary: #0F0F0F;
    --bg-secondary: #1A1A1A;
    --bg-tertiary: #262626;
    --bg-card: #1A1A1A;
    --bg-hover: rgba(255, 255, 255, 0.05);

    --text-primary: #FAFAFA;
    --text-secondary: #D4D4D4;
    --text-tertiary: #A3A3A3;
    --text-muted: #737373;
    --text-light: #525252;

    --border-light: rgba(255, 255, 255, 0.06);
    --border-default: rgba(255, 255, 255, 0.1);
    --border-strong: rgba(255, 255, 255, 0.15);

    --accent: #818CF8;
    --accent-light: #A5B4FC;
    --accent-muted: #6366F1;
    --accent-dark: #4F46E5;

    --primary: #818CF8;
    --primary-light: #A5B4FC;
    --primary-muted: #4F46E5;

    --secondary: #F472B6;
    --secondary-light: #F9A8D4;

    --success: #34D399;
    --success-light: #6EE7B7;
    --warning: #FBBF24;
    --warning-light: #FCD34D;
    --error: #F87171;
    --error-light: #FCA5A5;
    --info: #60A5FA;
    --info-light: #93C5FD;
}

/* ============================================
   Base Reset & Typography
   ============================================ */

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

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

body {
    font-family: var(--font-sans);
    font-size: var(--text-base);
    font-weight: var(--font-normal);
    line-height: var(--leading-normal);
    color: var(--text-primary);
    background: var(--bg-primary);
    overflow-x: hidden;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
    opacity: 0.03;
    pointer-events: none;
    z-index: 9999;
}

[data-theme="dark"] body::before {
    opacity: 0.02;
}

a {
    color: inherit;
    text-decoration: none;
    transition: color 0.3s var(--transition-smooth);
}

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

img {
    max-width: 100%;
    height: auto;
    display: block;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

input,
textarea,
select {
    font-family: inherit;
    font-size: inherit;
}

::selection {
    background: var(--accent);
    color: var(--bg-primary);
}

/* ============================================
   Typography
   ============================================ */

h1, h2, h3, h4, h5, h6 {
    font-weight: var(--font-semibold);
    line-height: var(--leading-tight);
    color: var(--text-primary);
}

h1 { font-size: var(--text-4xl); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-2xl); }
h4 { font-size: var(--text-xl); }
h5 { font-size: var(--text-lg); }
h6 { font-size: var(--text-base); }

p {
    margin-bottom: var(--space-4);
}

.text-display {
    font-family: var(--font-serif);
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: var(--font-light);
    letter-spacing: -0.02em;
    line-height: 1.1;
}

.text-headline {
    font-size: clamp(1.75rem, 4vw, 2.75rem);
    font-weight: var(--font-semibold);
    letter-spacing: -0.01em;
    line-height: var(--leading-tight);
}

.text-title {
    font-size: var(--text-xl);
    font-weight: var(--font-semibold);
    letter-spacing: -0.005em;
}

.text-subtitle {
    font-size: var(--text-lg);
    font-weight: var(--font-normal);
    color: var(--text-secondary);
}

.text-body {
    font-size: var(--text-base);
    font-weight: var(--font-normal);
    color: var(--text-secondary);
    line-height: var(--leading-relaxed);
}

.text-caption {
    font-size: var(--text-sm);
    font-weight: var(--font-normal);
    color: var(--text-tertiary);
    letter-spacing: 0.01em;
}

.text-overline {
    font-size: var(--text-xs);
    font-weight: var(--font-medium);
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--text-muted);
}

/* ============================================
   Layout
   ============================================ */

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-6);
}

.container-sm { max-width: 800px; }
.container-lg { max-width: 1400px; }
.container-xl { max-width: 1600px; }

.section {
    padding: var(--space-20) 0;
}

.section-sm { padding: var(--space-12) 0; }
.section-lg { padding: var(--space-32) 0; }

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

.header {
    position: sticky;
    top: 0;
    z-index: var(--z-sticky);
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(24px) saturate(180%);
    -webkit-backdrop-filter: blur(24px) saturate(180%);
    border-bottom: 1px solid var(--border-light);
    transition: all 0.3s var(--transition-smooth);
}

[data-theme="dark"] .header {
    background: rgba(15, 15, 15, 0.8);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: var(--header-height, 100px);
    padding: 0 var(--space-6);
    max-width: 1600px;
    margin: 0 auto;
}

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

.logo-icon {
    width: 32px;
    height: 32px;
    background: linear-gradient(135deg, var(--accent), var(--secondary));
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #FFFFFF;
    font-weight: var(--font-bold);
    font-size: var(--text-xs);
}

.logo-text {
    font-weight: var(--font-semibold);
    font-size: var(--text-base);
    letter-spacing: -0.01em;
    color: var(--text-primary);
}

.nav {
    display: flex;
    align-items: center;
    gap: var(--space-6);
}

.nav-link {
    font-size: 16px;
    font-weight: var(--font-medium);
    color: var(--text-secondary);
    padding: var(--space-2) 0;
    position: relative;
    transition: color 0.3s var(--transition-smooth);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--accent);
    transform: scaleX(0);
    transform-origin: right;
    transition: transform 0.3s var(--transition-smooth);
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-primary);
}

.nav-link:hover::after,
.nav-link.active::after {
    transform: scaleX(1);
    transform-origin: left;
}

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

.header-actions .theme-toggle-btn {
    margin-right: calc(var(--space-1) * -1);
}

.theme-toggle-btn {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: none;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s var(--transition-smooth);
}

.theme-toggle-btn:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

/* ============================================
   Buttons
   ============================================ */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-5);
    font-family: var(--font-sans);
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    letter-spacing: 0.01em;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s var(--transition-smooth);
    position: relative;
    overflow: hidden;
}

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

.btn-primary:hover {
    background: var(--accent-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3);
}

.btn-secondary {
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-strong);
}

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

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
}

.btn-ghost:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.btn-lg {
    padding: var(--space-3) var(--space-6);
    font-size: var(--text-base);
}

.btn-sm {
    padding: var(--space-2) var(--space-3);
    font-size: var(--text-xs);
}

.btn-icon {
    width: 36px;
    height: 36px;
    padding: 0;
    border-radius: var(--radius-md);
}

/* ============================================
   Cards
   ============================================ */

.card {
    background: var(--bg-card);
    border-radius: var(--radius-xl);
    overflow: hidden;
    transition: all 0.5s var(--transition-smooth);
    position: relative;
}

.card::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: inherit;
    padding: 1px;
    background: linear-gradient(135deg, transparent 0%, var(--border-light) 50%, transparent 100%);
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.4s var(--transition-smooth);
}

.card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.card:hover::before {
    opacity: 1;
}

.card-image {
    aspect-ratio: 4/3;
    position: relative;
    overflow: hidden;
    background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
}

.card-image::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(45deg, transparent 40%, rgba(255, 255, 255, 0.3) 50%, transparent 60%);
    transform: translateX(-100%);
    transition: transform 0.7s var(--transition-smooth);
}

.card:hover .card-image::before {
    transform: translateX(100%);
}

.card-body {
    padding: var(--space-6);
}

.card-title {
    font-size: var(--text-lg);
    font-weight: var(--font-semibold);
    margin-bottom: var(--space-2);
    color: var(--text-primary);
}

.card-subtitle {
    font-size: var(--text-sm);
    color: var(--text-tertiary);
    margin-bottom: var(--space-4);
}

.card-text {
    font-size: var(--text-base);
    color: var(--text-secondary);
    line-height: var(--leading-relaxed);
}

.card-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4) var(--space-6);
    border-top: 1px solid var(--border-light);
    background: var(--bg-secondary);
}

/* ============================================
   Tags & Badges - 轻微拟物感
   ============================================ */

.tag {
    display: inline-flex;
    align-items: center;
    padding: var(--space-1) var(--space-3);
    font-size: var(--text-xs);
    font-weight: var(--font-medium);
    color: var(--text-tertiary);
    background: linear-gradient(145deg, 
        rgba(248, 249, 250, 1) 0%, 
        rgba(241, 243, 245, 1) 100%);
    border-radius: var(--radius-full);
    transition: all 0.3s var(--transition-smooth);
    box-shadow: 
        0 1px 2px rgba(0, 0, 0, 0.03),
        inset 0 1px 0 rgba(255, 255, 255, 0.5);
    border: 1px solid rgba(0, 0, 0, 0.04);
}

[data-theme="dark"] .tag {
    background: linear-gradient(145deg, 
        rgba(50, 52, 58, 1) 0%, 
        rgba(40, 42, 48, 1) 100%);
    box-shadow: 
        0 1px 2px rgba(0, 0, 0, 0.1),
        inset 0 1px 0 rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.03);
}

.tag:hover {
    background: linear-gradient(145deg, 
        rgba(241, 243, 245, 1) 0%, 
        rgba(233, 236, 239, 1) 100%);
    color: var(--text-secondary);
    box-shadow: 
        0 2px 4px rgba(0, 0, 0, 0.05),
        inset 0 1px 0 rgba(255, 255, 255, 0.6);
}

[data-theme="dark"] .tag:hover {
    background: linear-gradient(145deg, 
        rgba(55, 57, 63, 1) 0%, 
        rgba(45, 47, 53, 1) 100%);
    box-shadow: 
        0 2px 4px rgba(0, 0, 0, 0.15),
        inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

.badge {
    display: inline-flex;
    align-items: center;
    padding: var(--space-1) var(--space-2);
    font-size: var(--text-xs);
    font-weight: var(--font-semibold);
    color: #FFFFFF;
    background: linear-gradient(145deg, 
        rgba(99, 102, 241, 1) 0%, 
        rgba(79, 70, 229, 1) 100%);
    border-radius: var(--radius-sm);
    box-shadow: 
        0 1px 2px rgba(99, 102, 241, 0.3),
        0 2px 4px rgba(0, 0, 0, 0.1),
        inset 0 1px 0 rgba(255, 255, 255, 0.2),
        inset 0 -1px 0 rgba(0, 0, 0, 0.1);
    text-shadow: 0 1px 0 rgba(0, 0, 0, 0.2);
}

/* ============================================
   Forms
   ============================================ */

.form-group {
    margin-bottom: var(--space-5);
}

.form-label {
    display: block;
    font-size: var(--text-xs);
    font-weight: var(--font-medium);
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-tertiary);
    margin-bottom: var(--space-2);
}

.form-input {
    width: 100%;
    padding: var(--space-4) var(--space-5);
    font-size: var(--text-base);
    color: var(--text-primary);
    background: transparent;
    border: 1px solid var(--border-default);
    border-radius: var(--radius-lg);
    transition: all 0.3s var(--transition-smooth);
}

.form-input::placeholder {
    color: var(--text-light);
}

.form-input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(26, 26, 26, 0.08);
}

[data-theme="dark"] .form-input:focus {
    box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.08);
}

.form-input-lg {
    padding: var(--space-5) var(--space-6);
    font-size: var(--text-lg);
}

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

.footer {
    padding: var(--space-16) var(--space-6);
    background: var(--bg-card);
    border-top: 1px solid var(--border-light);
}

.footer-inner {
    max-width: 1200px;
    margin: 0 auto;
}

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

@media (max-width: 768px) {
    .footer-grid {
        grid-template-columns: 1fr;
        gap: var(--space-8);
    }
}

.footer-brand {
    max-width: 300px;
}

.footer-brand .logo {
    margin-bottom: var(--space-4);
}

.footer-brand p {
    font-size: var(--text-sm);
    color: var(--text-tertiary);
    line-height: var(--leading-relaxed);
}

.footer-title {
    font-size: var(--text-xs);
    font-weight: var(--font-semibold);
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: var(--space-4);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: var(--space-3);
}

.footer-links a {
    font-size: var(--text-sm);
    color: var(--text-tertiary);
    transition: color 0.3s var(--transition-smooth);
}

.footer-links a:hover {
    color: var(--text-primary);
}

.footer-bottom {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: var(--space-8);
    border-top: 1px solid var(--border-light);
}

.footer-copyright {
    font-size: var(--text-sm);
    color: var(--text-muted);
}

/* ============================================
   Animations
   ============================================ */

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

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.animate-fade-in {
    animation: fadeIn 0.6s var(--transition-smooth) forwards;
}

.animate-fade-in-up {
    animation: fadeInUp 0.8s var(--transition-smooth) forwards;
}

.animate-scale-in {
    animation: scaleIn 0.5s var(--transition-smooth) forwards;
}

.animate-float {
    animation: float 3s ease-in-out infinite;
}

/* ============================================
   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;
}

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

.text-primary { color: var(--text-primary); }
.text-secondary { color: var(--text-secondary); }
.text-tertiary { color: var(--text-tertiary); }
.text-muted { color: var(--text-muted); }

.bg-primary { background: var(--bg-primary); }
.bg-secondary { background: var(--bg-secondary); }
.bg-card { background: var(--bg-card); }

.rounded-sm { border-radius: var(--radius-sm); }
.rounded-md { 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-sm { box-shadow: var(--shadow-sm); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }
.shadow-xl { box-shadow: var(--shadow-xl); }

.hidden { display: none; }
.block { display: block; }
.inline-block { display: inline-block; }
.flex { display: flex; }
.grid { display: grid; }

.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-start { justify-content: flex-start; }
.justify-end { justify-content: flex-end; }

.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); }

.p-4 { padding: var(--space-4); }
.p-6 { padding: var(--space-6); }
.p-8 { padding: var(--space-8); }
.px-4 { padding-left: var(--space-4); padding-right: var(--space-4); }
.py-4 { padding-top: var(--space-4); padding-bottom: var(--space-4); }

.m-0 { margin: 0; }
.m-auto { margin: auto; }
.mx-auto { margin-left: auto; margin-right: auto; }
.my-4 { margin-top: var(--space-4); margin-bottom: var(--space-4); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }

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

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

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

.inset-0 { top: 0; right: 0; bottom: 0; left: 0; }

.opacity-0 { opacity: 0; }
.opacity-50 { opacity: 0.5; }
.opacity-100 { opacity: 1; }

.transition-all { transition: all 0.3s var(--transition-smooth); }
.transition-colors { transition: color 0.3s var(--transition-smooth), background-color 0.3s var(--transition-smooth), border-color 0.3s var(--transition-smooth); }
.transition-transform { transition: transform 0.3s var(--transition-smooth); }
.transition-opacity { transition: opacity 0.3s var(--transition-smooth); }

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

@media (max-width: 1024px) {
    .lg\:hidden { display: none; }
}

@media (max-width: 768px) {
    .md\:hidden { display: none; }

    .container {
        padding: 0 var(--space-4);
    }

    .section {
        padding: var(--space-12) 0;
    }

    .nav {
        display: none;
    }

    .footer-grid {
        grid-template-columns: 1fr;
    }

    .footer-bottom {
        flex-direction: column;
        gap: var(--space-4);
        text-align: center;
    }
}

@media (max-width: 640px) {
    .sm\:hidden { display: none; }

    h1 { font-size: var(--text-2xl); }
    h2 { font-size: var(--text-xl); }
    h3 { font-size: var(--text-lg); }

    .text-display {
        font-size: clamp(2rem, 8vw, 3rem);
    }
}

/* ============================================
   Print
   ============================================ */

@media print {
    .header,
    .footer,
    .btn,
    .no-print {
        display: none !important;
    }

    body {
        background: white;
        color: black;
    }

    .card {
        box-shadow: none;
        border: 1px solid #ddd;
    }
}