/* ================================================
   快连 - 全站统一样式表
   版本: v2.0 | 响应式设计 | 750+ 行
   ================================================ */

/* ==================== 变量定义 ==================== */
:root {
    /* 主色系 - 科技蓝紫渐变 */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --primary-glow: rgba(99, 102, 241, 0.25);
    --primary-bg: rgba(99, 102, 241, 0.06);

    /* 强调色 - 活力橙 */
    --accent: #f97316;
    --accent-dark: #ea580c;
    --accent-light: #fb923c;

    /* 功能色 */
    --success: #10b981;
    --success-light: #34d399;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #0ea5e9;

    /* 背景色 */
    --bg-primary: #030712;
    --bg-secondary: #0f172a;
    --bg-card: #0f1a2e;
    --bg-card-hover: #131f36;
    --bg-input: #1e293b;
    --bg-overlay: rgba(3, 7, 18, 0.85);

    /* 文字色 */
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --text-link: #818cf8;

    /* 边框 */
    --border: #1e293b;
    --border-light: #334155;
    --border-glow: rgba(99, 102, 241, 0.4);

    /* 间距 */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;
    --space-3xl: 64px;
    --space-4xl: 96px;

    /* 圆角 */
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --radius-xl: 20px;
    --radius-2xl: 28px;
    --radius-full: 9999px;

    /* 阴影 */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.5);
    --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.6);
    --shadow-glow: 0 0 30px var(--primary-glow);

    /* 过渡 */
    --transition-fast: 0.15s ease;
    --transition-base: 0.25s ease;
    --transition-slow: 0.4s ease;
    --transition-bounce: 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);

    /* 字体 */
    --font-sans: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
    --font-mono: 'Cascadia Code', 'Fira Code', 'Consolas', monospace;

    /* 容器 */
    --container-max: 1200px;
    --container-padding: 24px;

    /* 导航高度 */
    --nav-height: 64px;
}

/* ==================== 重置基础 ==================== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
    scroll-behavior: smooth;
    scrollbar-width: thin;
    scrollbar-color: var(--primary) var(--bg-secondary);
}

::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--primary);
    border-radius: var(--radius-full);
}

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

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.7;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    min-height: 100vh;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

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

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

input, textarea, select {
    font-family: inherit;
    font-size: inherit;
    outline: none;
    border: none;
}

ul, ol {
    list-style: none;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
    color: var(--text-primary);
}

/* ==================== 容器布局 ==================== */
.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

.container-fluid {
    width: 100%;
    padding: 0 var(--container-padding);
}

.section {
    padding: var(--space-4xl) 0;
    position: relative;
    z-index: 1;
}

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

.section-lg {
    padding: var(--space-4xl) 0;
}

/* ==================== 背景效果 ==================== */
.bg-grid {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image:
        linear-gradient(rgba(99, 102, 241, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(99, 102, 241, 0.05) 1px, transparent 1px);
    background-size: 60px 60px;
    pointer-events: none;
    z-index: 0;
}

.bg-radial {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(ellipse at 50% 0%, rgba(99, 102, 241, 0.12) 0%, transparent 60%);
    pointer-events: none;
    z-index: 0;
}

.bg-radial-accent {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(ellipse at 80% 50%, rgba(249, 115, 22, 0.06) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
}

/* ==================== 导航栏 ==================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    height: var(--nav-height);
    background: var(--bg-overlay);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 1px solid var(--border);
    transition: all var(--transition-base);
}

.navbar.scrolled {
    background: rgba(3, 7, 18, 0.96);
    box-shadow: var(--shadow-md);
}

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

.navbar-brand {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 1.35rem;
    font-weight: 800;
    color: var(--text-primary);
    letter-spacing: -0.5px;
}

.navbar-brand-icon {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    box-shadow: 0 4px 12px var(--primary-glow);
}

.navbar-brand-text {
    background: linear-gradient(135deg, var(--text-primary), var(--text-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.navbar-brand-sub {
    font-size: 0.55rem;
    color: var(--text-muted);
    display: block;
    margin-top: -4px;
    letter-spacing: 2px;
    text-transform: uppercase;
    font-weight: 600;
    -webkit-text-fill-color: var(--text-muted);
}

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

.navbar-nav a {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    padding: var(--space-sm) 0;
    position: relative;
    transition: color var(--transition-fast);
}

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

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

.navbar-nav a:hover::after,
.navbar-nav a.active::after {
    transform: scaleX(1);
}

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

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

.navbar-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--text-primary);
    border-radius: var(--radius-full);
    transition: all var(--transition-base);
}

/* ==================== 按钮 ==================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: 10px 24px;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
    white-space: nowrap;
    border: none;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    transition: left 0.5s;
}

.btn:hover::before {
    left: 100%;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: #fff;
    box-shadow: 0 4px 16px var(--primary-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px var(--primary-glow);
    filter: brightness(1.1);
}

.btn-accent {
    background: linear-gradient(135deg, var(--accent), var(--accent-dark));
    color: #fff;
    box-shadow: 0 4px 16px rgba(249, 115, 22, 0.3);
}

.btn-accent:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(249, 115, 22, 0.4);
    filter: brightness(1.1);
}

.btn-outline {
    background: transparent;
    color: var(--primary-light);
    border: 1.5px solid var(--primary);
}

.btn-outline:hover {
    background: var(--primary-bg);
    transform: translateY(-2px);
}

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
    border: 1.5px solid var(--border);
}

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

.btn-sm {
    padding: 6px 16px;
    font-size: 0.82rem;
    border-radius: var(--radius-sm);
}

.btn-lg {
    padding: 14px 36px;
    font-size: 1rem;
    border-radius: var(--radius-lg);
}

.btn-icon {
    width: 40px;
    height: 40px;
    padding: 0;
    border-radius: var(--radius-md);
}

/* ==================== 卡片 ==================== */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

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

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--primary-light));
    transform: scaleX(0);
    transition: transform var(--transition-base);
}

.card:hover::before {
    transform: scaleX(1);
}

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

.card-title {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: var(--space-xs);
}

.card-desc {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.card-icon {
    width: 52px;
    height: 52px;
    background: var(--primary-bg);
    border: 1px solid rgba(99, 102, 241, 0.15);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    margin-bottom: var(--space-lg);
    transition: all var(--transition-base);
}

.card:hover .card-icon {
    background: var(--primary);
    border-color: var(--primary);
    transform: scale(1.1);
}

/* ==================== Hero 区域 ==================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: var(--nav-height);
    position: relative;
    overflow: hidden;
}

.hero-split {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3xl);
    align-items: center;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    background: var(--primary-bg);
    border: 1px solid rgba(99, 102, 241, 0.2);
    padding: 5px 14px;
    border-radius: var(--radius-full);
    font-size: 0.78rem;
    color: var(--primary-light);
    font-weight: 600;
    margin-bottom: var(--space-lg);
    letter-spacing: 0.5px;
}

.hero-title {
    font-size: 3.2rem;
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: var(--space-lg);
    letter-spacing: -1px;
}

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

.hero-desc {
    color: var(--text-secondary);
    font-size: 1.05rem;
    margin-bottom: var(--space-xl);
    line-height: 1.8;
    max-width: 500px;
}

.hero-btns {
    display: flex;
    gap: var(--space-md);
    flex-wrap: wrap;
    margin-bottom: var(--space-xl);
}

.hero-stats {
    display: flex;
    gap: var(--space-xl);
}

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

.hero-stat-val {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--primary-light);
}

.hero-stat-lbl {
    font-size: 0.72rem;
    color: var(--text-muted);
    margin-top: 2px;
}

.hero-chips {
    display: flex;
    gap: var(--space-sm);
    flex-wrap: wrap;
}

.chip {
    padding: 4px 12px;
    background: rgba(99, 102, 241, 0.08);
    border: 1px solid rgba(99, 102, 241, 0.15);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* ==================== 特性网格 ==================== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.features-grid-2 {
    grid-template-columns: repeat(2, 1fr);
}

.features-grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

/* ==================== 节点网格 ==================== */
.node-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: var(--space-md);
}

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

.node-card:hover {
    transform: translateY(-4px);
    border-color: var(--primary);
    background: var(--bg-card-hover);
}

.node-card.selected {
    border-color: var(--primary);
    background: var(--primary-bg);
}

.node-icon {
    font-size: 1.8rem;
    margin-bottom: var(--space-sm);
}

.node-name {
    font-size: 0.82rem;
    font-weight: 700;
    margin-bottom: 2px;
}

.node-ping {
    font-size: 0.72rem;
    color: var(--success);
    font-weight: 600;
}

.node-ping.high {
    color: var(--warning);
}

.node-ping.medium {
    color: var(--accent);
}

/* ==================== 用户评价 ==================== */
.testi-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.testi-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
}

.testi-stars {
    color: #fbbf24;
    font-size: 0.85rem;
    letter-spacing: 3px;
    margin-bottom: var(--space-md);
}

.testi-text {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--space-lg);
}

.testi-author {
    display: flex;
    align-items: center;
    gap: var(--space-md);
}

.testi-avatar {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
    flex-shrink: 0;
}

.testi-name {
    font-weight: 700;
    font-size: 0.9rem;
}

.testi-role {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 2px;
}

/* ==================== FAQ 手风琴 ==================== */
.faq-wrap {
    max-width: 760px;
    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: border-color var(--transition-fast);
}

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

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

.faq-q {
    padding: var(--space-lg) var(--space-xl);
    cursor: pointer;
    font-weight: 600;
    font-size: 0.95rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--space-md);
    transition: all var(--transition-fast);
}

.faq-q:hover {
    color: var(--primary-light);
}

.faq-q::after {
    content: '+';
    font-size: 1.3rem;
    color: var(--primary);
    transition: transform var(--transition-base);
    flex-shrink: 0;
    font-weight: 300;
}

.faq-item.active .faq-q::after {
    transform: rotate(45deg);
}

.faq-a {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
}

.faq-item.active .faq-a {
    max-height: 400px;
}

.faq-a-inner {
    padding: 0 var(--space-xl) var(--space-lg);
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.8;
}

/* ==================== 下载卡片 ==================== */
.dl-platforms {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-xl);
    margin: var(--space-3xl) 0;
}

.dl-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl) var(--space-xl);
    text-align: center;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.dl-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary);
    box-shadow: var(--shadow-lg), 0 0 40px var(--primary-glow);
}

.dl-card-tag {
    position: absolute;
    top: var(--space-lg);
    right: var(--space-lg);
    padding: 3px 10px;
    border-radius: var(--radius-sm);
    font-size: 0.7rem;
    font-weight: 700;
}

.dl-card-tag.hot {
    background: rgba(239, 68, 68, 0.12);
    color: var(--danger);
}

.dl-card-tag.new {
    background: rgba(99, 102, 241, 0.12);
    color: var(--primary-light);
}

.dl-card-tag.rec {
    background: rgba(249, 115, 22, 0.12);
    color: var(--accent);
}

.dl-card-icon {
    font-size: 2.4rem;
    margin-bottom: var(--space-lg);
}

.dl-card h3 {
    font-size: 1.2rem;
    margin-bottom: var(--space-xs);
}

.dl-card-ver {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: var(--space-md);
}

.dl-card p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-xl);
    min-height: 40px;
}

/* ==================== 教程页 ==================== */
.tutorial-nav {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-md);
    margin: var(--space-3xl) 0;
}

.tutorial-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    display: flex;
    align-items: flex-start;
    gap: var(--space-lg);
    transition: all var(--transition-base);
    text-decoration: none;
    color: inherit;
}

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

.tutorial-num {
    width: 44px;
    height: 44px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 1.1rem;
    flex-shrink: 0;
    box-shadow: 0 4px 12px var(--primary-glow);
}

.tutorial-info h4 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: var(--space-xs);
}

.tutorial-info p {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* ==================== 面包屑 ==================== */
.breadcrumb {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-lg) 0;
    font-size: 0.85rem;
    color: var(--text-muted);
}

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

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

.breadcrumb span {
    color: var(--text-muted);
}

/* ==================== 标题组件 ==================== */
.eyebrow {
    display: inline-block;
    padding: 4px 14px;
    background: var(--primary-bg);
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-radius: var(--radius-full);
    font-size: 0.72rem;
    color: var(--primary-light);
    font-weight: 600;
    letter-spacing: 1px;
    text-transform: uppercase;
    margin-bottom: var(--space-md);
}

.section-title {
    font-size: 2.2rem;
    font-weight: 800;
    margin-bottom: var(--space-md);
    letter-spacing: -0.5px;
}

.section-desc {
    color: var(--text-secondary);
    font-size: 1rem;
    max-width: 560px;
    margin-bottom: var(--space-3xl);
}

.center {
    text-align: center;
}

.ma {
    margin-left: auto;
    margin-right: auto;
}

/* ==================== CTA 区域 ==================== */
.cta-section {
    padding: var(--space-4xl) 0;
    text-align: center;
    position: relative;
    z-index: 1;
}

.cta-box {
    background: linear-gradient(135deg, var(--bg-card), var(--bg-secondary));
    border: 1px solid var(--border);
    border-radius: var(--radius-2xl);
    padding: var(--space-4xl) var(--space-2xl);
    max-width: 860px;
    margin: 0 auto;
    position: relative;
    overflow: hidden;
}

.cta-box::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.06) 0%, transparent 60%);
    pointer-events: none;
}

.cta-box h2 {
    font-size: 2.4rem;
    font-weight: 800;
    margin-bottom: var(--space-md);
    position: relative;
}

.cta-box p {
    font-size: 1.05rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-xl);
    position: relative;
}

.cta-btns {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    flex-wrap: wrap;
    position: relative;
}

.cta-chips {
    display: flex;
    gap: var(--space-sm);
    justify-content: center;
    margin-top: var(--space-xl);
    flex-wrap: wrap;
    position: relative;
}

.cta-chip {
    padding: 4px 12px;
    background: rgba(99, 102, 241, 0.08);
    border: 1px solid rgba(99, 102, 241, 0.15);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    color: var(--text-secondary);
}

/* ==================== 页脚 ==================== */
.footer {
    border-top: 1px solid var(--border);
    padding: var(--space-3xl) 0 var(--space-xl);
    position: relative;
    z-index: 1;
}

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

.footer-brand p {
    color: var(--text-muted);
    font-size: 0.88rem;
    margin-top: var(--space-md);
    line-height: 1.7;
}

.footer-title {
    font-size: 0.88rem;
    font-weight: 700;
    margin-bottom: var(--space-lg);
    color: var(--text-primary);
}

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

.footer-links a {
    color: var(--text-muted);
    font-size: 0.85rem;
    transition: color var(--transition-fast);
}

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

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

.footer-copy {
    color: var(--text-muted);
    font-size: 0.8rem;
}

.footer-social {
    display: flex;
    gap: var(--space-md);
}

.footer-social a {
    width: 36px;
    height: 36px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all var(--transition-base);
    font-size: 1rem;
}

.footer-social a:hover {
    border-color: var(--primary);
    color: var(--primary-light);
    transform: translateY(-2px);
}

/* ==================== 步骤流程 ==================== */
.steps-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-lg);
    margin: var(--space-3xl) 0;
}

.step-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    text-align: center;
    transition: all var(--transition-base);
}

.step-card:hover {
    border-color: var(--primary);
    transform: translateY(-4px);
}

.step-num {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--space-lg);
    font-weight: 800;
    font-size: 1.2rem;
    box-shadow: 0 4px 16px var(--primary-glow);
}

.step-card h4 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: var(--space-sm);
}

.step-card p {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* ==================== 信息面板 ==================== */
.info-panels {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-xl);
    margin: var(--space-3xl) 0;
}

.info-panel {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
}

.info-panel h3 {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-md);
    border-bottom: 1px solid var(--border);
}

.info-list {
    list-style: none;
}

.info-list li {
    display: flex;
    align-items: flex-start;
    gap: var(--space-sm);
    padding: var(--space-sm) 0;
    font-size: 0.88rem;
    color: var(--text-secondary);
    border-bottom: 1px solid rgba(99, 102, 241, 0.05);
}

.info-list li:last-child {
    border-bottom: none;
}

.info-list li::before {
    content: '✓';
    color: var(--success);
    font-weight: 700;
    flex-shrink: 0;
    margin-top: 1px;
}

/* ==================== 表格 ==================== */
.table-wrap {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    overflow: hidden;
    margin: var(--space-3xl) 0;
}

.table-wrap h3 {
    padding: var(--space-lg) var(--space-xl);
    border-bottom: 1px solid var(--border);
    font-size: 1.05rem;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
}

.data-table th {
    padding: var(--space-md) var(--space-xl);
    text-align: left;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
    background: rgba(99, 102, 241, 0.05);
    border-bottom: 1px solid var(--border);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.data-table td {
    padding: var(--space-md) var(--space-xl);
    font-size: 0.88rem;
    border-bottom: 1px solid rgba(99, 102, 241, 0.05);
    color: var(--text-secondary);
}

.data-table tr:last-child td {
    border-bottom: none;
}

.data-table tr:hover td {
    background: rgba(99, 102, 241, 0.03);
}

.status-badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--success);
}

.status-badge::before {
    content: '';
    width: 6px;
    height: 6px;
    background: var(--success);
    border-radius: 50%;
}

/* ==================== AI 组件 ==================== */
.ai-widget {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.ai-widget::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.05) 0%, transparent 60%);
    animation: ai-rotate 15s linear infinite;
}

@keyframes ai-rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.ai-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--space-lg);
    font-size: 1.6rem;
    box-shadow: 0 0 30px var(--primary-glow);
    position: relative;
    z-index: 1;
}

.ai-widget h3 {
    font-size: 1.2rem;
    margin-bottom: var(--space-sm);
    position: relative;
    z-index: 1;
}

.ai-widget > p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: var(--space-xl);
    position: relative;
    z-index: 1;
}

.ai-tags {
    display: flex;
    gap: var(--space-sm);
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: var(--space-xl);
    position: relative;
    z-index: 1;
}

.ai-tag {
    padding: 6px 14px;
    background: rgba(99, 102, 241, 0.08);
    border: 1px solid rgba(99, 102, 241, 0.15);
    border-radius: var(--radius-md);
    cursor: pointer;
    font-size: 0.82rem;
    color: var(--text-secondary);
    transition: all var(--transition-base);
}

.ai-tag:hover,
.ai-tag.active {
    background: rgba(99, 102, 241, 0.15);
    border-color: var(--primary);
    color: var(--primary-light);
}

/* ==================== 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-success { color: var(--success); }
.text-warning { color: var(--warning); }
.text-danger { color: var(--danger); }
.text-sm { font-size: 0.875rem; }
.text-xs { font-size: 0.75rem; }
.text-lg { font-size: 1.125rem; }
.text-xl { font-size: 1.25rem; }
.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); }
.p-sm { padding: var(--space-sm); }
.p-md { padding: var(--space-md); }
.p-lg { padding: var(--space-lg); }
.p-xl { padding: var(--space-xl); }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }
.d-flex { display: flex; }
.d-grid { display: grid; }
.d-block { display: block; }
.d-none { display: none; }
.flex-wrap { flex-wrap: wrap; }
.align-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.flex-1 { flex: 1; }
.w-full { width: 100%; }
.rounded { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }
.overflow-hidden { overflow: hidden; }
.relative { position: relative; }
.absolute { position: absolute; }

/* ==================== 响应式断点 ==================== */

/* 超大屏 */
@media (max-width: 1280px) {
    .features-grid-4 {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* 平板 */
@media (max-width: 1024px) {
    :root {
        --container-padding: 20px;
    }

    .hero-split {
        grid-template-columns: 1fr;
        gap: var(--space-2xl);
    }

    .hero-title {
        font-size: 2.6rem;
    }

    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .features-grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }

    .node-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .testi-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .dl-platforms {
        grid-template-columns: repeat(2, 1fr);
    }

    .steps-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .info-panels {
        grid-template-columns: 1fr 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: var(--space-2xl);
    }

    .navbar-nav {
        display: none;
    }

    .navbar-toggle {
        display: flex;
    }
}

/* 大手机 */
@media (max-width: 768px) {
    :root {
        --container-padding: 16px;
        --space-4xl: 72px;
        --space-3xl: 56px;
    }

    .hero {
        min-height: auto;
        padding: calc(var(--nav-height) + 40px) 0 60px;
    }

    .hero-title {
        font-size: 2.2rem;
    }

    .hero-desc {
        font-size: 0.95rem;
    }

    .hero-stats {
        gap: var(--space-lg);
    }

    .section-title {
        font-size: 1.7rem;
    }

    .features-grid,
    .features-grid-2 {
        grid-template-columns: 1fr;
    }

    .features-grid-4 {
        grid-template-columns: repeat(2, 1fr);
    }

    .node-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

    .dl-platforms {
        grid-template-columns: 1fr;
    }

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

    .info-panels {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
    }

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

    .cta-box {
        padding: var(--space-3xl) var(--space-xl);
    }

    .cta-box h2 {
        font-size: 1.8rem;
    }

    .tutorial-nav {
        grid-template-columns: 1fr;
    }
}

/* 小手机 */
@media (max-width: 480px) {
    :root {
        --space-4xl: 56px;
        --space-3xl: 40px;
    }

    .hero-title {
        font-size: 1.8rem;
    }

    .hero-btns {
        flex-direction: column;
    }

    .hero-btns .btn {
        width: 100%;
    }

    .hero-stats {
        flex-direction: column;
        gap: var(--space-md);
    }

    .features-grid-4 {
        grid-template-columns: 1fr;
    }

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

    .node-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .faq-q {
        padding: var(--space-md) var(--space-lg);
        font-size: 0.88rem;
    }

    .faq-a-inner {
        padding: 0 var(--space-lg) var(--space-md);
    }
}

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

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

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

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.animate-fadeIn {
    animation: fadeIn 0.6s ease forwards;
}

.animate-slideIn {
    animation: slideIn 0.5s ease forwards;
}

.animate-pulse {
    animation: pulse 2s ease-in-out infinite;
}

/* ==================== 打印样式 ==================== */
@media print {
    .navbar,
    .footer,
    .btn,
    .hero-btns {
        display: none !important;
    }

    body {
        background: #fff;
        color: #000;
    }

    .card,
    .dl-card {
        border: 1px solid #ddd;
        background: #fff;
    }
}