/**
 * 快连官网全新CSS样式设计
 * 现代简洁、专业可信、技术感与亲和力并存
 * 响应式设计、移动端优先、性能优化
 */

/* ========================================
   1. CSS Variables (变量定义)
   ======================================== */
:root {
    /* 主色调：科技蓝+信任绿 */
    --primary: #0066FF;
    --primary-dark: #0052CC;
    --primary-light: #3385FF;
    --accent: #00D47E;
    --accent-dark: #00B368;
    --accent-warm: #FF6B35;
    --accent-warm-dark: #E55A2B;
    
    /* 背景色 */
    --bg-primary: #0A0F1C;
    --bg-secondary: #111827;
    --bg-card: #1F2937;
    --bg-hover: #374151;
    --bg-overlay: rgba(10, 15, 28, 0.95);
    
    /* 文字色 */
    --text-primary: #F9FAFB;
    --text-secondary: #9CA3AF;
    --text-muted: #6B7280;
    --text-link: #60A5FA;
    
    /* 边框色 */
    --border: rgba(255, 255, 255, 0.1);
    --border-hover: rgba(255, 255, 255, 0.2);
    --border-primary: rgba(0, 102, 255, 0.3);
    
    /* 阴影 */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.6);
    --glow-primary: 0 0 20px rgba(0, 102, 255, 0.3);
    --glow-accent: 0 0 20px rgba(0, 212, 126, 0.3);
    --glow-warm: 0 0 20px rgba(255, 107, 53, 0.3);
    
    /* 圆角 */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --radius-xl: 20px;
    --radius-full: 9999px;
    
    /* 间距 */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    
    /* 过渡 */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* 字体 */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, monospace;
}

/* ========================================
   2. CSS Reset (重置样式)
   ======================================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

img, picture, video, canvas, svg {
    display: block;
    max-width: 100%;
    height: auto;
}

input, button, textarea, select {
    font: inherit;
    color: inherit;
}

button {
    background: none;
    border: none;
    cursor: pointer;
}

a {
    color: inherit;
    text-decoration: none;
}

ul, ol {
    list-style: none;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
}

/* ========================================
   3. Typography (基础排版)
   ======================================== */
body {
    font-family: var(--font-sans);
}

h1 {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 700;
    letter-spacing: -0.02em;
}

h2 {
    font-size: clamp(1.5rem, 4vw, 2.5rem);
    font-weight: 700;
    letter-spacing: -0.01em;
}

h3 {
    font-size: clamp(1.25rem, 3vw, 1.5rem);
    font-weight: 600;
}

h4 {
    font-size: 1.125rem;
    font-weight: 600;
}

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

code, pre, .tech-data {
    font-family: var(--font-mono);
}

code {
    background: var(--bg-hover);
    padding: 0.2em 0.4em;
    border-radius: var(--radius-sm);
    font-size: 0.875em;
}

pre {
    background: var(--bg-card);
    padding: var(--space-lg);
    border-radius: var(--radius-md);
    overflow-x: auto;
}

.text-gradient {
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ========================================
   4. Layout (布局系统)
   ======================================== */
.container {
    width: 100%;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.section {
    padding: var(--space-3xl) 0;
}

.section-alt {
    background-color: var(--bg-secondary);
}

.section-dark {
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.grid {
    display: grid;
    gap: var(--space-lg);
}

.grid-2 {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-3 {
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.grid-4 {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

/* ========================================
   5. Components - Buttons (按钮组件)
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    cursor: pointer;
    border: 2px solid transparent;
    white-space: nowrap;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    border-color: var(--primary);
}

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

.btn-primary:active {
    transform: translateY(0);
}

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

.btn-outline:hover {
    background: var(--bg-hover);
    border-color: var(--primary);
    color: var(--primary);
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-icon {
    font-size: 1.2em;
    transition: transform var(--transition-fast);
}

.btn:hover .btn-icon {
    transform: translateX(4px);
}

/* ========================================
   6. Components - Cards (卡片组件)
   ======================================== */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    transition: all var(--transition-base);
}

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

.card-header {
    margin-bottom: var(--space-lg);
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.card-meta {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.card-body {
    color: var(--text-secondary);
}

/* Feature Card */
.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    transition: all var(--transition-base);
}

.feature-card:hover {
    border-color: var(--primary);
    box-shadow: var(--glow-primary);
    transform: translateY(-4px);
}

.feature-icon {
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    border-radius: var(--radius-md);
    margin-bottom: var(--space-lg);
}

.feature-icon.blue {
    background: linear-gradient(135deg, rgba(0, 102, 255, 0.2) 0%, rgba(0, 102, 255, 0.1) 100%);
}

.feature-icon.green {
    background: linear-gradient(135deg, rgba(0, 212, 126, 0.2) 0%, rgba(0, 212, 126, 0.1) 100%);
}

.feature-icon.purple {
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.2) 0%, rgba(139, 92, 246, 0.1) 100%);
}

.feature-icon.orange {
    background: linear-gradient(135deg, rgba(255, 107, 53, 0.2) 0%, rgba(255, 107, 53, 0.1) 100%);
}

.feature-icon.cyan {
    background: linear-gradient(135deg, rgba(6, 182, 212, 0.2) 0%, rgba(6, 182, 212, 0.1) 100%);
}

.feature-icon.red {
    background: linear-gradient(135deg, rgba(239, 68, 68, 0.2) 0%, rgba(239, 68, 68, 0.1) 100%);
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 0;
}

/* Download Card */
.download-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    text-align: center;
    transition: all var(--transition-base);
}

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

.download-icon {
    font-size: 3rem;
    margin-bottom: var(--space-md);
}

.download-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.download-card p {
    color: var(--text-secondary);
    margin-bottom: var(--space-sm);
}

.download-version {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--accent);
    margin-bottom: var(--space-lg);
}

/* Platform Card */
.platform-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    transition: all var(--transition-base);
}

.platform-card:hover {
    border-color: var(--primary);
    box-shadow: var(--glow-primary);
}

.platform-header {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
    margin-bottom: var(--space-xl);
    padding-bottom: var(--space-lg);
    border-bottom: 1px solid var(--border);
}

.platform-icon {
    font-size: 2.5rem;
}

.platform-info h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--space-xs);
}

.platform-version {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--accent);
}

.platform-details {
    margin-bottom: var(--space-xl);
}

.detail-row {
    display: flex;
    padding: var(--space-sm) 0;
    border-bottom: 1px solid var(--border);
}

.detail-row:last-child {
    border-bottom: none;
}

.detail-label {
    width: 100px;
    flex-shrink: 0;
    color: var(--text-muted);
    font-size: 0.875rem;
}

.detail-value {
    color: var(--text-primary);
    font-size: 0.875rem;
}

.platform-actions {
    display: flex;
    gap: var(--space-md);
    flex-wrap: wrap;
}

.platform-note {
    margin-top: var(--space-lg);
    padding: var(--space-md);
    background: var(--bg-hover);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-style: italic;
}

/* Guide Card */
.guide-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    margin-bottom: var(--space-xl);
}

.guide-card:last-child {
    margin-bottom: 0;
}

.guide-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--space-xl);
    padding-bottom: var(--space-md);
    border-bottom: 1px solid var(--border);
}

.guide-steps {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.guide-step {
    display: flex;
    gap: var(--space-lg);
    align-items: flex-start;
}

.guide-step .step-num {
    width: 32px;
    height: 32px;
    background: var(--primary);
    color: white;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    flex-shrink: 0;
}

.guide-step h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--space-xs);
}

.guide-step p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    margin-bottom: 0;
}

/* ========================================
   7. Components - Badges (徽章组件)
   ======================================== */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.75rem;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.badge-green {
    background: rgba(0, 212, 126, 0.15);
    color: var(--accent);
    border: 1px solid rgba(0, 212, 126, 0.3);
}

.badge-red {
    background: rgba(239, 68, 68, 0.15);
    color: #EF4444;
    border: 1px solid rgba(239, 68, 68, 0.3);
}

.badge-yellow {
    background: rgba(251, 191, 36, 0.15);
    color: #FBBF24;
    border: 1px solid rgba(251, 191, 36, 0.3);
}

.badge-blue {
    background: rgba(0, 102, 255, 0.15);
    color: var(--primary-light);
    border: 1px solid rgba(0, 102, 255, 0.3);
}

.badge-purple {
    background: rgba(139, 92, 246, 0.15);
    color: #8B5CF6;
    border: 1px solid rgba(139, 92, 246, 0.3);
}

/* ========================================
   8. Components - Live Time Module (时间模块)
   ======================================== */
.live-time-module {
    background: linear-gradient(135deg, rgba(0, 102, 255, 0.1) 0%, rgba(0, 212, 126, 0.1) 100%);
    border: 1px solid var(--border-primary);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.live-time-header {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding-bottom: var(--space-md);
    border-bottom: 1px solid var(--border);
}

.live-time-header .icon {
    font-size: 1.5rem;
}

.live-time-header h4 {
    font-size: 1.125rem;
    font-weight: 600;
}

.live-time-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-lg);
}

.live-time-item {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.live-time-label {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.live-time-value {
    font-family: var(--font-mono);
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--accent);
}

.live-time-value.highlight {
    color: var(--primary);
}

.live-time-footer {
    margin-top: var(--space-md);
    padding-top: var(--space-md);
    border-top: 1px solid var(--border);
    font-size: 0.875rem;
    color: var(--text-muted);
    text-align: center;
}

/* Animated pulse for live indicator */
.live-indicator {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
}

.live-indicator::before {
    content: '';
    width: 8px;
    height: 8px;
    background: var(--accent);
    border-radius: 50%;
    animation: pulse-glow 2s ease-in-out infinite;
}

@keyframes pulse-glow {
    0%, 100% {
        opacity: 1;
        box-shadow: 0 0 5px var(--accent);
    }
    50% {
        opacity: 0.6;
        box-shadow: 0 0 15px var(--accent), 0 0 30px var(--accent);
    }
}

/* ========================================
   9. Components - Data Display (数据展示)
   ======================================== */
.data-highlight {
    background: linear-gradient(135deg, var(--bg-card) 0%, rgba(0, 102, 255, 0.1) 100%);
    border-left: 3px solid var(--primary);
    padding: var(--space-lg);
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    margin: var(--space-lg) 0;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-top: var(--space-xs);
}

/* Performance Chart */
.perf-chart {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
}

.perf-chart-header {
    margin-bottom: var(--space-xl);
}

.perf-chart-title {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--space-xs);
}

.perf-chart-subtitle {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.perf-bar {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin-bottom: var(--space-md);
}

.perf-bar:last-child {
    margin-bottom: 0;
}

.perf-bar-label {
    width: 80px;
    flex-shrink: 0;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.perf-bar-track {
    flex: 1;
    height: 8px;
    background: var(--bg-hover);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.perf-bar-fill {
    height: 100%;
    border-radius: var(--radius-full);
    transition: width 1s ease-out;
}

.perf-bar-fill.primary {
    background: linear-gradient(90deg, var(--primary) 0%, var(--primary-light) 100%);
}

.perf-bar-fill.accent {
    background: linear-gradient(90deg, var(--accent) 0%, #00F5A0 100%);
}

.perf-bar-fill.warm {
    background: linear-gradient(90deg, var(--accent-warm) 0%, #FF8F66 100%);
}

.perf-bar-value {
    width: 60px;
    flex-shrink: 0;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    font-weight: 600;
    text-align: right;
}

/* Comparison Table */
.compare-table {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.compare-header {
    display: grid;
    grid-template-columns: 1.5fr repeat(3, 1fr);
    background: var(--bg-hover);
    padding: var(--space-md) var(--space-lg);
    font-weight: 600;
    text-align: center;
}

.compare-header > div:first-child {
    text-align: left;
}

.compare-row {
    display: grid;
    grid-template-columns: 1.5fr repeat(3, 1fr);
    padding: var(--space-md) var(--space-lg);
    border-bottom: 1px solid var(--border);
    transition: background var(--transition-fast);
}

.compare-row:last-child {
    border-bottom: none;
}

.compare-row:hover {
    background: var(--bg-hover);
}

.compare-label {
    font-weight: 500;
}

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

.compare-note {
    margin-top: var(--space-xl);
    padding: var(--space-lg);
    background: var(--bg-hover);
    border-radius: var(--radius-md);
    border-left: 3px solid var(--primary);
}

.compare-note p {
    margin-bottom: 0;
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

/* ========================================
   10. Sections - Header (头部区域)
   ======================================== */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--bg-overlay);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    padding: var(--space-md) 0;
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-xl);
}

.breadcrumb {
    position: absolute;
    top: var(--space-md);
    left: var(--space-lg);
    font-size: 0.75rem;
    color: var(--text-muted);
}

.breadcrumb li {
    display: inline;
}

.breadcrumb li:not(:last-child)::after {
    content: ' / ';
    margin: 0 var(--space-xs);
}

.breadcrumb a {
    color: var(--text-muted);
    transition: color var(--transition-fast);
}

.breadcrumb a:hover {
    color: var(--primary);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    transition: color var(--transition-fast);
}

.logo:hover {
    color: var(--primary);
}

.logo-icon {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: white;
}

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

.nav a {
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
    position: relative;
}

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

.nav a.active::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary);
    border-radius: var(--radius-full);
}

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: var(--space-sm);
}

.mobile-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    border-radius: var(--radius-full);
    transition: all var(--transition-fast);
}

/* ========================================
   11. Sections - Hero (英雄区域)
   ======================================== */
.hero {
    padding: var(--space-3xl) 0;
    text-align: center;
    background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(ellipse at center top, rgba(0, 102, 255, 0.15) 0%, transparent 70%);
    pointer-events: none;
}

.hero .container {
    position: relative;
    z-index: 1;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: var(--space-sm) var(--space-lg);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-xl);
}

.badge-icon {
    font-size: 1.25rem;
}

.hero h1 {
    margin-bottom: var(--space-xl);
    line-height: 1.2;
}

.hero h1 .highlight {
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    max-width: 800px;
    margin: 0 auto var(--space-2xl);
    font-size: 1.125rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: var(--space-lg);
    margin-bottom: var(--space-3xl);
    flex-wrap: wrap;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--space-xl);
    max-width: 800px;
    margin: 0 auto;
}

.hero-stat {
    text-align: center;
    padding: var(--space-lg);
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
}

.hero-stat:hover {
    border-color: var(--primary);
    box-shadow: var(--glow-primary);
}

.hero-stat-number {
    font-size: 2rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-stat-label {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-top: var(--space-xs);
}

/* ========================================
   12. Sections - Features (功能模块)
   ======================================== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--space-xl);
}

/* ========================================
   13. Sections - Tech (技术原理)
   ======================================== */
.tech-diagram {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    margin-bottom: var(--space-2xl);
    overflow-x: auto;
}

.tech-diagram svg {
    max-width: 100%;
    height: auto;
}

.tech-steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-xl);
}

.tech-step {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    transition: all var(--transition-base);
}

.tech-step:hover {
    border-color: var(--primary);
    box-shadow: var(--glow-primary);
}

.tech-step-num {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
    margin-bottom: var(--space-lg);
}

.tech-step h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
}

.tech-step p {
    color: var(--text-secondary);
    margin-bottom: 0;
}

/* ========================================
   14. Sections - Steps (步骤)
   ======================================== */
.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--space-xl);
}

.step-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
    text-align: center;
    position: relative;
    transition: all var(--transition-base);
}

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

.step-num {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-dark) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    font-weight: 700;
    color: white;
    margin: 0 auto var(--space-lg);
}

.step-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
}

.step-card p {
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
}

.step-card time {
    display: block;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--accent);
    background: var(--bg-hover);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-sm);
}

/* ========================================
   15. Sections - Download (下载)
   ======================================== */
.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-xl);
}

/* ========================================
   16. Sections - FAQ (常见问题)
   ======================================== */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    margin-bottom: var(--space-md);
    overflow: hidden;
    transition: all var(--transition-base);
}

.faq-item:last-child {
    margin-bottom: 0;
}

.faq-item:hover {
    border-color: var(--primary);
}

.faq-item.open {
    border-color: var(--primary);
    box-shadow: var(--glow-primary);
}

.faq-question {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-lg);
    text-align: left;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    background: transparent;
    border: none;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.faq-question:hover {
    background: var(--bg-hover);
}

.faq-icon {
    font-size: 1.5rem;
    font-weight: 300;
    color: var(--primary);
    transition: transform var(--transition-fast);
}

.faq-item.open .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-base);
}

.faq-answer p {
    padding: 0 var(--space-lg) var(--space-lg);
    color: var(--text-secondary);
    line-height: 1.7;
}

.faq-answer p:first-child {
    padding-top: var(--space-sm);
}

/* ========================================
   17. Sections - CTA (行动号召)
   ======================================== */
.cta-section {
    text-align: center;
    padding: var(--space-3xl) 0;
}

.cta-section h2 {
    margin-bottom: var(--space-lg);
}

.cta-section p {
    max-width: 600px;
    margin: 0 auto var(--space-xl);
    color: var(--text-secondary);
    font-size: 1.125rem;
}

/* ========================================
   18. Sections - Footer (页脚)
   ======================================== */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    padding: var(--space-3xl) 0 var(--space-xl);
}

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

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

.footer-brand p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    line-height: 1.7;
    max-width: 300px;
}

.footer-links h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--space-lg);
    color: var(--text-primary);
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.footer-links a {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    padding-top: var(--space-xl);
    border-top: 1px solid var(--border);
    text-align: center;
    color: var(--text-muted);
    font-size: 0.875rem;
}

.footer-bottom p {
    margin-bottom: var(--space-xs);
}

.footer-bottom p:last-child {
    margin-bottom: 0;
}

/* ========================================
   19. Sections - Version Info (版本信息)
   ======================================== */
.version-info {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--space-xl);
}

.version-info h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-md);
    border-bottom: 1px solid var(--border);
}

.version-info ul {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.version-info li {
    position: relative;
    padding-left: var(--space-lg);
    color: var(--text-secondary);
    line-height: 1.6;
}

.version-info li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: 600;
}

/* ========================================
   20. Sections - Section Headers
   ======================================== */
.section-title {
    text-align: center;
    margin-bottom: var(--space-md);
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.125rem;
    margin-bottom: var(--space-2xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* ========================================
   21. Animations (动画效果)
   ======================================== */
@keyframes fade-in-up {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fade-in {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes slide-in-left {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slide-in-right {
    from {
        opacity: 0;
        transform: translateX(20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

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

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

.animate-fade-in-up {
    animation: fade-in-up 0.6s ease-out forwards;
}

.animate-fade-in {
    animation: fade-in 0.4s ease-out forwards;
}

.animate-slide-in-left {
    animation: slide-in-left 0.6s ease-out forwards;
}

.animate-slide-in-right {
    animation: slide-in-right 0.6s ease-out forwards;
}

.animate-scale-in {
    animation: scale-in 0.4s ease-out forwards;
}

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

/* Stagger animations */
.stagger-1 { animation-delay: 0.1s; }
.stagger-2 { animation-delay: 0.2s; }
.stagger-3 { animation-delay: 0.3s; }
.stagger-4 { animation-delay: 0.4s; }
.stagger-5 { animation-delay: 0.5s; }
.stagger-6 { animation-delay: 0.6s; }

/* ========================================
   22. Utilities (工具类)
   ======================================== */
.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-muted { color: var(--text-muted); }
.text-accent { color: var(--accent); }
.text-primary-color { color: var(--primary); }

.font-mono { font-family: var(--font-mono); }
.font-bold { font-weight: 700; }
.font-semibold { font-weight: 600; }

.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }
.mt-2xl { margin-top: var(--space-2xl); }

.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }
.mb-2xl { margin-bottom: var(--space-2xl); }

.py-xl { padding-top: var(--space-xl); padding-bottom: var(--space-xl); }
.py-2xl { padding-top: var(--space-2xl); padding-bottom: var(--space-2xl); }

.hidden { display: none; }
.visible { visibility: visible; }
.invisible { visibility: hidden; }

.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;
}

/* ========================================
   23. Responsive (响应式设计)
   ======================================== */
@media screen and (max-width: 1024px) {
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-brand {
        grid-column: span 2;
    }
    
    .compare-header,
    .compare-row {
        grid-template-columns: 1.2fr repeat(3, 1fr);
    }
}

@media screen and (max-width: 768px) {
    :root {
        --space-xl: 1.5rem;
        --space-2xl: 2rem;
        --space-3xl: 3rem;
    }
    
    .header .container {
        flex-wrap: wrap;
    }
    
    .breadcrumb {
        display: none;
    }
    
    .nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-overlay);
        backdrop-filter: blur(10px);
        flex-direction: column;
        padding: var(--space-lg);
        border-bottom: 1px solid var(--border);
        gap: var(--space-md);
    }
    
    .nav.open {
        display: flex;
    }
    
    .nav a {
        padding: var(--space-sm) 0;
    }
    
    .mobile-toggle {
        display: flex;
    }
    
    .hero-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .hero-stat-number {
        font-size: 1.5rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .tech-steps {
        grid-template-columns: 1fr;
    }
    
    .steps {
        grid-template-columns: 1fr;
    }
    
    .download-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-brand {
        grid-column: span 1;
    }
    
    .compare-header,
    .compare-row {
        grid-template-columns: 1fr;
        padding: var(--space-md);
    }
    
    .compare-header > div:not(:first-child),
    .compare-row > div:not(:first-child) {
        display: none;
    }
    
    .compare-header > div:first-child {
        text-align: left;
    }
    
    .compare-label {
        margin-bottom: var(--space-sm);
    }
    
    .compare-value {
        display: block;
        text-align: left;
        padding-left: var(--space-lg);
        position: relative;
    }
    
    .compare-value::before {
        content: '→';
        position: absolute;
        left: 0;
        color: var(--text-muted);
    }
    
    .live-time-content {
        grid-template-columns: 1fr;
    }
    
    .platform-header {
        flex-direction: column;
        text-align: center;
    }
    
    .platform-actions {
        flex-direction: column;
    }
    
    .platform-actions .btn {
        width: 100%;
    }
}

@media screen and (max-width: 480px) {
    :root {
        --space-lg: 1rem;
        --space-xl: 1.25rem;
        --space-2xl: 1.5rem;
        --space-3xl: 2rem;
    }
    
    .container {
        padding: 0 var(--space-md);
    }
    
    .hero h1 {
        font-size: 1.75rem;
    }
    
    .hero-desc {
        font-size: 1rem;
    }
    
    .hero-actions {
        flex-direction: column;
        align-items: stretch;
    }
    
    .hero-actions .btn {
        width: 100%;
        justify-content: center;
    }
    
    .hero-stats {
        grid-template-columns: 1fr 1fr;
        gap: var(--space-md);
    }
    
    .hero-stat {
        padding: var(--space-md);
    }
    
    .download-grid {
        grid-template-columns: 1fr;
    }
    
    .btn-lg {
        padding: 0.875rem 1.5rem;
        font-size: 1rem;
    }
    
    .card {
        padding: var(--space-lg);
    }
    
    .feature-card,
    .step-card,
    .guide-card {
        padding: var(--space-lg);
    }
    
    .stat-number {
        font-size: 2rem;
    }
}

/* ========================================
   24. Print Styles (打印样式)
   ======================================== */
@media print {
    .header,
    .mobile-toggle,
    .hero-actions,
    .cta-section,
    .footer {
        display: none;
    }
    
    body {
        background: white;
        color: black;
    }
    
    .section {
        padding: 1rem 0;
    }
    
    .card,
    .feature-card {
        border: 1px solid #ddd;
        box-shadow: none;
    }
}

/* ========================================
   25. Reduced Motion (减少动画)
   ======================================== */
@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;
    }
}

/* ========================================
   26. Dark Mode (深色模式) - 增强
   ======================================== */
@media (prefers-color-scheme: dark) {
    :root {
        /* Already dark by default, but can enhance */
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --border: rgba(255, 255, 255, 0.3);
        --border-hover: rgba(255, 255, 255, 0.5);
        --text-secondary: #d1d5db;
    }
}