/* ============================================================
   maifafa.com — 跨境电商老王个人官网
   样式文件 (CSS3)
   ============================================================ */

/* ---------- CSS 自定义属性（设计 Token） ---------- */
:root {
  /* 颜色 */
  --bg-primary: #0a0e1a;
  --bg-secondary: #111827;
  --bg-card: #1a2332;
  --bg-card-hover: #1e293b;
  --brand-blue: #3b82f6;
  --brand-green: #10b981;
  --brand-purple: #8b5cf6;
  --brand-gradient: linear-gradient(135deg, #3b82f6, #10b981);
  --brand-gradient-purple: linear-gradient(135deg, #8b5cf6, #3b82f6);
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border-color: rgba(59, 130, 246, 0.15);
  --border-hover: rgba(59, 130, 246, 0.35);
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.3);
  --shadow-glow-blue: 0 0 30px rgba(59, 130, 246, 0.15);
  --shadow-glow-green: 0 0 30px rgba(16, 185, 129, 0.15);

  /* 字体 */
  --font-main: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Consolas", monospace;

  /* 尺寸 */
  --nav-height: 72px;
  --section-gap: 100px;
  --container-max: 1200px;
  --container-padding: 0 24px;

  /* 圆角 */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* 过渡 */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* ---------- Reset & 基础样式 ---------- */
*,
*::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-main);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

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

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

ul {
  list-style: none;
}

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

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

/* ---------- 通用标题 ---------- */
.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-tag {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--brand-blue);
  background: rgba(59, 130, 246, 0.1);
  padding: 6px 16px;
  border-radius: var(--radius-full);
  margin-bottom: 16px;
}

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 16px;
  background: var(--brand-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-subtitle {
  font-size: clamp(0.95rem, 1.5vw, 1.15rem);
  color: var(--text-secondary);
  max-width: 640px;
  margin: 0 auto;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
  white-space: nowrap;
}

.btn-primary {
  background: var(--brand-gradient);
  color: #fff;
  box-shadow: 0 4px 16px rgba(59, 130, 246, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(59, 130, 246, 0.45);
}

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

.btn-secondary:hover {
  background: rgba(59, 130, 246, 0.1);
  border-color: var(--brand-blue);
  transform: translateY(-2px);
}

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

.btn-outline:hover {
  background: var(--brand-blue);
  color: #fff;
  transform: translateY(-2px);
}

.btn-sm {
  padding: 10px 20px;
  font-size: 0.85rem;
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.05rem;
}

/* ============================================================
   1. 导航栏 (Navbar)
   ============================================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  display: flex;
  align-items: center;
  transition: all var(--transition-normal);
}

.navbar.scrolled {
  background: rgba(10, 14, 26, 0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.navbar-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.navbar-brand .brand-icon {
  width: 36px;
  height: 36px;
  background: var(--brand-gradient);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  color: #fff;
  font-weight: 800;
}

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

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
  position: relative;
  padding: 4px 0;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--brand-gradient);
  transition: width var(--transition-normal);
  border-radius: 2px;
}

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

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.navbar-cta {
  display: flex;
  align-items: center;
  gap: 16px;
}

.navbar-cta .btn {
  padding: 10px 22px;
  font-size: 0.85rem;
}

/* 汉堡菜单按钮 */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 40px;
  height: 40px;
  cursor: pointer;
  background: transparent;
  border: none;
  padding: 0;
  z-index: 1001;
}

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

.hamburger span + span {
  margin-top: 5px;
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

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

/* 科技感网格背景 */
.hero-bg-grid {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image:
    linear-gradient(rgba(59, 130, 246, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(59, 130, 246, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  z-index: 0;
}

/* 光晕效果 */
.hero-glow {
  position: absolute;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  filter: blur(120px);
  opacity: 0.15;
  pointer-events: none;
  z-index: 0;
}

.hero-glow-1 {
  top: -200px;
  right: -200px;
  background: var(--brand-blue);
  animation: glowFloat 8s ease-in-out infinite;
}

.hero-glow-2 {
  bottom: -200px;
  left: -200px;
  background: var(--brand-green);
  animation: glowFloat 10s ease-in-out infinite reverse;
}

/* 浮动粒子 */
.hero-particles {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 0;
  overflow: hidden;
}

.particle {
  position: absolute;
  width: 4px;
  height: 4px;
  background: var(--brand-blue);
  border-radius: 50%;
  opacity: 0;
  animation: particleFloat 6s ease-in-out infinite;
}

.particle:nth-child(1) { left: 10%; top: 20%; animation-delay: 0s; }
.particle:nth-child(2) { left: 25%; top: 60%; animation-delay: 1.5s; background: var(--brand-green); }
.particle:nth-child(3) { left: 50%; top: 30%; animation-delay: 3s; }
.particle:nth-child(4) { left: 70%; top: 70%; animation-delay: 4.5s; background: var(--brand-green); }
.particle:nth-child(5) { left: 85%; top: 40%; animation-delay: 2s; }
.particle:nth-child(6) { left: 40%; top: 80%; animation-delay: 3.5s; }
.particle:nth-child(7) { left: 15%; top: 45%; animation-delay: 1s; background: var(--brand-green); }
.particle:nth-child(8) { left: 90%; top: 15%; animation-delay: 5s; }
.particle:nth-child(9) { left: 60%; top: 10%; animation-delay: 2.5s; }
.particle:nth-child(10) { left: 5%; top: 85%; animation-delay: 4s; background: var(--brand-green); }

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 860px;
  margin: 0 auto;
  padding: 60px 0;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--brand-green);
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.2);
  padding: 6px 18px;
  border-radius: var(--radius-full);
  margin-bottom: 28px;
  letter-spacing: 1px;
}

.hero-badge i {
  font-size: 0.7rem;
}

.hero-title {
  font-size: clamp(2.2rem, 6vw, 4rem);
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 24px;
  letter-spacing: -1px;
}

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

.hero-subtitle {
  font-size: clamp(0.95rem, 2vw, 1.2rem);
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 40px;
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
}

.hero-subtitle span {
  display: inline-block;
  position: relative;
}

.hero-subtitle span::after {
  content: '';
  display: block;
  width: 100%;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--brand-blue), transparent);
  margin-top: 2px;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 48px;
  margin-top: 56px;
  flex-wrap: wrap;
}

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

.hero-stat-item .stat-number {
  font-size: 1.8rem;
  font-weight: 700;
  background: var(--brand-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-stat-item .stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* ============================================================
   3. 信任背书区 (Trust)
   ============================================================ */
.trust {
  padding: var(--section-gap) 0;
  background: var(--bg-secondary);
}

.trust-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.trust-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px 24px;
  text-align: center;
  transition: all var(--transition-normal);
}

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

.trust-card-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin: 0 auto 16px;
}

.trust-card-icon.blue {
  background: rgba(59, 130, 246, 0.12);
  color: var(--brand-blue);
}

.trust-card-icon.green {
  background: rgba(16, 185, 129, 0.12);
  color: var(--brand-green);
}

.trust-card-icon.purple {
  background: rgba(139, 92, 246, 0.12);
  color: var(--brand-purple);
}

.trust-card-icon.amber {
  background: rgba(245, 158, 11, 0.12);
  color: #f59e0b;
}

.trust-card h4 {
  font-size: 1rem;
  margin-bottom: 8px;
}

.trust-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.trust-card .trust-stat {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--brand-blue);
  margin: 12px 0 4px;
}

.trust-book {
  display: flex;
  align-items: center;
  gap: 20px;
  text-align: left;
  padding: 24px;
}

.trust-book-cover {
  width: 80px;
  height: 110px;
  background: var(--brand-gradient);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  color: #fff;
  flex-shrink: 0;
  box-shadow: 0 4px 16px rgba(59, 130, 246, 0.2);
}

.trust-book-info h4 {
  font-size: 0.95rem;
  margin-bottom: 4px;
}

.trust-book-info p {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.trust-book-info .trust-stat {
  font-size: 1.1rem;
  margin: 0;
}

/* ============================================================
   4. 核心产品矩阵 (Products)
   ============================================================ */
.products {
  padding: var(--section-gap) 0;
}

.products-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.product-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  text-align: center;
  transition: all var(--transition-normal);
  position: relative;
  display: flex;
  flex-direction: column;
}

.product-card:hover {
  transform: translateY(-8px);
  border-color: var(--brand-blue);
  box-shadow: var(--shadow-card), var(--shadow-glow-blue);
}

.product-card.featured {
  border-color: var(--brand-blue);
  background: linear-gradient(180deg, rgba(59, 130, 246, 0.06), var(--bg-card));
}

.product-card.featured::before {
  content: '推荐';
  position: absolute;
  top: -1px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 1px;
  color: #fff;
  background: var(--brand-gradient);
  padding: 4px 16px;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
}

.product-icon {
  width: 60px;
  height: 60px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin: 0 auto 20px;
}

.product-icon.blue {
  background: rgba(59, 130, 246, 0.12);
  color: var(--brand-blue);
}

.product-icon.green {
  background: rgba(16, 185, 129, 0.12);
  color: var(--brand-green);
}

.product-icon.purple {
  background: rgba(139, 92, 246, 0.12);
  color: var(--brand-purple);
}

.product-card h3 {
  font-size: 1.15rem;
  margin-bottom: 10px;
}

.product-card .product-desc {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 20px;
  flex-grow: 1;
}

.product-price {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 20px;
  letter-spacing: -1px;
}

.product-price .price-currency {
  font-size: 1rem;
  font-weight: 600;
  vertical-align: super;
  margin-right: 2px;
}

.product-price .price-original {
  font-size: 0.9rem;
  color: var(--text-muted);
  text-decoration: line-through;
  font-weight: 400;
  margin-left: 8px;
}

.product-card .btn {
  width: 100%;
}

/* ============================================================
   5. AI 系统展示区 (AI Systems)
   ============================================================ */
.ai-systems {
  padding: var(--section-gap) 0;
  background: var(--bg-secondary);
}

.ai-systems-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.ai-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.ai-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-card);
}

.ai-card.pod {
  border-color: rgba(59, 130, 246, 0.25);
}

.ai-card.pod:hover {
  box-shadow: var(--shadow-glow-blue);
}

.ai-card.erp {
  border-color: rgba(139, 92, 246, 0.25);
}

.ai-card.erp:hover {
  box-shadow: 0 0 30px rgba(139, 92, 246, 0.15);
}

.ai-card-badge {
  position: absolute;
  top: 16px;
  right: 16px;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 1px;
  color: #fff;
  background: var(--brand-gradient);
  padding: 4px 14px;
  border-radius: var(--radius-full);
}

.ai-card-badge.invite-only {
  background: linear-gradient(135deg, #f59e0b, #ef4444);
}

.ai-card-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 20px;
}

.ai-card-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  flex-shrink: 0;
}

.ai-card.pod .ai-card-icon {
  background: rgba(59, 130, 246, 0.12);
  color: var(--brand-blue);
}

.ai-card.erp .ai-card-icon {
  background: rgba(139, 92, 246, 0.12);
  color: var(--brand-purple);
}

.ai-card-header h3 {
  font-size: 1.15rem;
}

.ai-card-header .ai-domain {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.ai-features {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin: 24px 0;
}

.ai-feature {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.88rem;
  color: var(--text-secondary);
}

.ai-feature i {
  font-size: 0.75rem;
  color: var(--brand-green);
  width: 18px;
  height: 18px;
  background: rgba(16, 185, 129, 0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.ai-card .btn {
  width: 100%;
  margin-top: 8px;
}

.ai-note {
  text-align: center;
  margin-top: 32px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.ai-note a {
  color: var(--brand-blue);
  text-decoration: underline;
}

/* ============================================================
   6. 资源整合区 (Resources)
   ============================================================ */
.resources {
  padding: var(--section-gap) 0;
}

.resources-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.resource-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 24px;
  text-align: center;
  transition: all var(--transition-normal);
  cursor: pointer;
}

.resource-card:hover {
  transform: translateY(-6px) scale(1.02);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-card), var(--shadow-glow-blue);
  background: var(--bg-card-hover);
}

.resource-card .resource-icon {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin: 0 auto 20px;
  transition: all var(--transition-normal);
}

.resource-card:hover .resource-icon {
  transform: scale(1.1);
}

.resource-card .resource-icon.blue {
  background: rgba(59, 130, 246, 0.12);
  color: var(--brand-blue);
}

.resource-card .resource-icon.green {
  background: rgba(16, 185, 129, 0.12);
  color: var(--brand-green);
}

.resource-card .resource-icon.purple {
  background: rgba(139, 92, 246, 0.12);
  color: var(--brand-purple);
}

.resource-card .resource-icon.amber {
  background: rgba(245, 158, 11, 0.12);
  color: #f59e0b;
}

.resource-card h4 {
  font-size: 1.05rem;
  margin-bottom: 8px;
}

.resource-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ============================================================
   7. 最新内容动态区 (Content)
   ============================================================ */
.content {
  padding: var(--section-gap) 0;
  background: var(--bg-secondary);
}

.content-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 40px;
  align-items: start;
}

.content-column-title {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.content-column-title i {
  color: var(--brand-blue);
}

/* 文章卡片 */
.article-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  transition: all var(--transition-normal);
  cursor: pointer;
}

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

.article-card .article-date {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.article-card h4 {
  font-size: 0.95rem;
  margin-bottom: 6px;
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-card .article-excerpt {
  font-size: 0.82rem;
  color: var(--text-secondary);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-card .article-more {
  font-size: 0.8rem;
  color: var(--brand-blue);
  margin-top: 8px;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* 视频卡片 */
.video-placeholder {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all var(--transition-normal);
  cursor: pointer;
}

.video-placeholder:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-card);
}

.video-thumb {
  width: 100%;
  aspect-ratio: 16 / 9;
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), rgba(16, 185, 129, 0.1));
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.video-thumb i {
  font-size: 3rem;
  color: var(--brand-blue);
  opacity: 0.6;
  transition: all var(--transition-normal);
}

.video-placeholder:hover .video-thumb i {
  opacity: 1;
  transform: scale(1.1);
}

.video-info {
  padding: 16px 20px;
}

.video-info h4 {
  font-size: 0.9rem;
  margin-bottom: 4px;
}

.video-info p {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ============================================================
   8. 页脚 (Footer)
   ============================================================ */
.footer {
  background: #060a14;
  border-top: 1px solid var(--border-color);
  padding: 60px 0 30px;
}

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand h3 {
  font-size: 1.2rem;
  margin-bottom: 12px;
}

.footer-brand h3 span {
  background: var(--brand-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.footer-brand p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.7;
  max-width: 320px;
}

.footer-col h4 {
  font-size: 0.9rem;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.footer-col ul li {
  margin-bottom: 10px;
}

.footer-col ul li a {
  font-size: 0.85rem;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}

.footer-col ul li a:hover {
  color: var(--brand-blue);
}

/* 社交媒体链接 */
.footer-social {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 20px;
}

.footer-social a {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  color: var(--text-secondary);
  transition: all var(--transition-normal);
}

.footer-social a:hover {
  background: var(--brand-blue);
  border-color: var(--brand-blue);
  color: #fff;
  transform: translateY(-3px);
}

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-bottom p {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.footer-links {
  display: flex;
  gap: 20px;
}

.footer-links a {
  font-size: 0.82rem;
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

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

/* ============================================================
   9. 模态弹窗 (Modal)
   ============================================================ */
.modal-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  z-index: 2000;
  align-items: center;
  justify-content: center;
  animation: fadeIn 0.25s ease;
}

.modal-overlay.active {
  display: flex;
}

.modal-content {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 40px;
  max-width: 400px;
  width: 90%;
  text-align: center;
  animation: modalSlideUp 0.3s ease;
  position: relative;
}

.modal-close {
  position: absolute;
  top: 12px;
  right: 16px;
  font-size: 1.4rem;
  color: var(--text-muted);
  background: none;
  cursor: pointer;
  transition: color var(--transition-fast);
}

.modal-close:hover {
  color: var(--text-primary);
}

.modal-qr-placeholder {
  width: 200px;
  height: 200px;
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), rgba(16, 185, 129, 0.1));
  border: 2px dashed var(--border-hover);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  font-size: 3rem;
  color: var(--text-muted);
}

.modal-content h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
}

.modal-content p {
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.modal-content .modal-tip {
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* ============================================================
   10. 滚动入场动画 (Scroll Reveal)
   ============================================================ */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }

/* ============================================================
   11. 关键帧动画
   ============================================================ */
@keyframes glowFloat {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(30px, -30px) scale(1.05); }
}

@keyframes particleFloat {
  0%, 100% {
    opacity: 0;
    transform: translateY(0) scale(0);
  }
  20% { opacity: 0.6; }
  50% {
    opacity: 0.8;
    transform: translateY(-30px) scale(1);
  }
  80% { opacity: 0.4; }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes modalSlideUp {
  from {
    opacity: 0;
    transform: translateY(20px) scale(0.95);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

/* ============================================================
   12. 响应式设计
   ============================================================ */

/* 平板 (≤ 1024px) */
@media (max-width: 1024px) {
  .trust-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

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

/* 手机 (≤ 768px) */
@media (max-width: 768px) {
  :root {
    --nav-height: 64px;
    --section-gap: 60px;
    --container-padding: 0 16px;
  }

  /* 导航 */
  .nav-links {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(10, 14, 26, 0.98);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 24px;
    z-index: 999;
  }

  .nav-links.active {
    display: flex;
  }

  .nav-links a {
    font-size: 1.2rem;
  }

  .navbar-cta .btn {
    padding: 8px 16px;
    font-size: 0.78rem;
  }

  .hamburger {
    display: flex;
  }

  .navbar .navbar-cta .btn-text {
    display: none;
  }

  /* Hero */
  .hero-title {
    font-size: clamp(1.8rem, 8vw, 2.5rem);
  }

  .hero-subtitle {
    font-size: 0.9rem;
  }

  .hero-stats {
    gap: 24px;
  }

  .hero-stat-item .stat-number {
    font-size: 1.4rem;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
    padding: 0 20px;
  }

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

  /* Trust */
  .trust-grid {
    grid-template-columns: 1fr;
  }

  .trust-book {
    flex-direction: column;
    text-align: center;
  }

  /* Products */
  .products-grid {
    grid-template-columns: 1fr;
    max-width: 420px;
    margin-left: auto;
    margin-right: auto;
  }

  /* AI Systems */
  .ai-systems-grid {
    grid-template-columns: 1fr;
  }

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

  /* Resources */
  .resources-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }

  .resource-card {
    padding: 24px 16px;
  }

  .resource-card .resource-icon {
    width: 48px;
    height: 48px;
    font-size: 1.2rem;
  }

  /* Content */
  .content-grid {
    grid-template-columns: 1fr;
  }

  /* Footer */
  .footer-content {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }

  /* Modal */
  .modal-content {
    padding: 32px 24px;
  }
}

/* 小手机 (≤ 480px) */
@media (max-width: 480px) {
  .resources-grid {
    grid-template-columns: 1fr;
  }

  .hero-stats {
    flex-direction: column;
    gap: 16px;
  }
}