/* ==========================================================================
   扬帆云 (Yangfan Cloud) - 极致深空炭灰 3D 动态视觉系统
   Target domain: yangfanyunjic.homes
   ========================================================================== */

/* 1. 全局变量与设计系统 */
:root {
  --bg-dark: #07090e;
  --bg-card: rgba(15, 19, 28, 0.75);
  --bg-card-hover: rgba(22, 28, 42, 0.9);
  --bg-surface: #0e121b;
  --border-color: rgba(255, 255, 255, 0.08);
  --border-glow: rgba(0, 242, 254, 0.35);
  
  --primary: #00f2fe;
  --primary-gradient: linear-gradient(135deg, #00f2fe 0%, #4facfe 100%);
  --accent-purple: linear-gradient(135deg, #7928ca 0%, #ff0080 100%);
  --accent-gold: linear-gradient(135deg, #f6d365 0%, #fda085 100%);
  --accent-green: #10b981;
  
  --text-main: #f8fafc;
  --text-sub: #94a3b8;
  --text-muted: #64748b;
  
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --transition-fast: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  --shadow-glow: 0 0 35px rgba(0, 242, 254, 0.25);
  --shadow-card: 0 25px 50px -12px rgba(0, 0, 0, 0.7);
}

/* 2. 重置与基础设置 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-dark);
  color: var(--text-main);
  font-family: var(--font-sans);
  overflow-x: hidden;
  -webkit-tap-highlight-color: transparent;
}

body {
  line-height: 1.6;
  min-height: 100vh;
  background: 
    radial-gradient(circle at 15% 15%, rgba(0, 242, 254, 0.08) 0%, transparent 45%),
    radial-gradient(circle at 85% 50%, rgba(121, 40, 202, 0.08) 0%, transparent 50%),
    radial-gradient(circle at 50% 85%, rgba(16, 185, 129, 0.05) 0%, transparent 45%),
    var(--bg-dark);
  background-attachment: fixed;
}

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

ul {
  list-style: none;
}

/* 3. 布局容器 */
.container {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}

section {
  padding: 110px 0;
  position: relative;
  scroll-margin-top: 85px;
}

/* 4. 导航栏 Header 与导航目录菜单 */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(7, 9, 14, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition-fast);
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 85px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-main);
  cursor: pointer;
  user-select: none;
  transition: transform var(--transition-fast);
}

.logo:hover {
  transform: translateY(-2px);
}

.logo-icon {
  width: 44px;
  height: 44px;
  background: var(--primary-gradient);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 20px rgba(0, 242, 254, 0.4);
  transition: var(--transition-normal);
}

.logo:hover .logo-icon {
  box-shadow: 0 0 30px rgba(0, 242, 254, 0.8);
  transform: rotate(5deg) scale(1.05);
}

.logo-text {
  background: linear-gradient(180deg, #ffffff 0%, #cbd5e1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: -0.5px;
}

.logo-tag {
  font-size: 0.7rem;
  padding: 2px 8px;
  background: rgba(0, 242, 254, 0.15);
  color: var(--primary);
  border: 1px solid rgba(0, 242, 254, 0.3);
  border-radius: 20px;
  font-weight: 600;
  text-transform: uppercase;
}

/* 页眉导航目录菜单 */
.header-nav {
  display: flex;
  align-items: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.03);
  padding: 6px 12px;
  border-radius: 30px;
  border: 1px solid rgba(255, 255, 255, 0.06);
}

.header-nav-link {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-sub);
  padding: 6px 14px;
  border-radius: 20px;
  transition: all var(--transition-fast);
}

.header-nav-link:hover {
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.08);
}

.header-nav-link.active {
  color: var(--primary);
  background: rgba(0, 242, 254, 0.12);
  border: 1px solid rgba(0, 242, 254, 0.25);
}

.nav-cta {
  display: flex;
  align-items: center;
  gap: 14px;
}

/* 5. 按钮样式组件 */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: var(--primary-gradient);
  color: #040810;
  font-weight: 700;
  font-size: 1rem;
  padding: 14px 28px;
  border-radius: 12px;
  box-shadow: 0 8px 25px -5px rgba(0, 242, 254, 0.4);
  transition: all var(--transition-fast);
  cursor: pointer;
  border: none;
  position: relative;
  overflow: hidden;
}

.btn-primary::before {
  content: '';
  position: absolute;
  top: 0; left: -100%;
  width: 100%; height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.4), transparent);
  transition: 0.5s;
}

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

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 35px -5px rgba(0, 242, 254, 0.6);
  color: #000;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-main);
  font-weight: 600;
  font-size: 1rem;
  padding: 14px 28px;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  backdrop-filter: blur(10px);
  transition: all var(--transition-fast);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

.btn-accent {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: var(--accent-purple);
  color: #ffffff;
  font-weight: 700;
  font-size: 1rem;
  padding: 14px 28px;
  border-radius: 12px;
  box-shadow: 0 8px 25px -5px rgba(255, 0, 128, 0.4);
  transition: all var(--transition-fast);
  cursor: pointer;
  border: none;
}

.btn-accent:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 35px -5px rgba(255, 0, 128, 0.7);
  color: #ffffff;
}

/* 6. Hero 主视觉区 - 左右双栏动态分布结构 */
.hero {
  padding-top: 165px;
  padding-bottom: 110px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 50px;
  align-items: center;
}

.hero-content {
  text-align: left;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: rgba(0, 242, 254, 0.1);
  border: 1px solid rgba(0, 242, 254, 0.25);
  border-radius: 30px;
  color: var(--primary);
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 24px;
  box-shadow: 0 0 15px rgba(0, 242, 254, 0.15);
}

.hero-badge-dot {
  width: 8px;
  height: 8px;
  background-color: var(--primary);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--primary);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(0, 242, 254, 0.7); }
  70% { transform: scale(1); box-shadow: 0 0 0 10px rgba(0, 242, 254, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(0, 242, 254, 0); }
}

.hero-title {
  font-size: 3.4rem;
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -1px;
  margin-bottom: 24px;
  background: linear-gradient(180deg, #ffffff 0%, #cbd5e1 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

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

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-sub);
  margin-bottom: 36px;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  padding: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  backdrop-filter: blur(16px);
  box-shadow: var(--shadow-card);
}

.stat-item {
  text-align: left;
}

.stat-number {
  font-size: 1.85rem;
  font-weight: 800;
  color: var(--text-main);
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--text-sub);
  margin-top: 2px;
}

/* 6.1 Hero 右侧动态图卡视觉模块 */
.hero-visual {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.hero-visual-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 24px;
  padding: 24px;
  backdrop-filter: blur(20px);
  box-shadow: var(--shadow-card);
  position: relative;
  overflow: hidden;
  transition: var(--transition-normal);
}

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

/* 测速仪表盘动态图卡 */
.speed-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.speed-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1rem;
}

.ping-tag {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-green);
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid rgba(16, 185, 129, 0.3);
  padding: 4px 10px;
  border-radius: 20px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.ping-dot {
  width: 6px;
  height: 6px;
  background-color: var(--accent-green);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--accent-green);
  animation: pulse 1.5s infinite;
}

.speed-display {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  background: rgba(0, 0, 0, 0.3);
  padding: 20px;
  border-radius: 16px;
  border: 1px solid rgba(255, 255, 255, 0.05);
  margin-bottom: 16px;
}

.speed-value {
  font-size: 2.5rem;
  font-weight: 900;
  color: var(--primary);
  line-height: 1;
  letter-spacing: -1px;
}

.speed-unit {
  font-size: 0.9rem;
  color: var(--text-sub);
  font-weight: 600;
}

.speed-bar-container {
  height: 8px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 10px;
  overflow: hidden;
  position: relative;
}

.speed-bar-fill {
  height: 100%;
  width: 92%;
  background: var(--primary-gradient);
  border-radius: 10px;
  box-shadow: 0 0 15px var(--primary);
  animation: shimmer 3s infinite linear;
}

@keyframes shimmer {
  0% { opacity: 0.8; }
  50% { opacity: 1; }
  100% { opacity: 0.8; }
}

/* 动态节点实时状态图卡 */
.node-list-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.node-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: rgba(255, 255, 255, 0.03);
  padding: 12px 16px;
  border-radius: 14px;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

.node-info {
  display: flex;
  align-items: center;
  gap: 12px;
}

.node-flag {
  font-size: 1.2rem;
}

.node-name {
  font-weight: 600;
  font-size: 0.9rem;
}

.node-type {
  font-size: 0.75rem;
  color: var(--primary);
  background: rgba(0, 242, 254, 0.1);
  padding: 2px 8px;
  border-radius: 8px;
}

.node-ping {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-green);
}

/* 7. 通用 Section 头部 */
.section-header {
  text-align: center;
  max-width: 750px;
  margin: 0 auto 65px;
}

.section-tag {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--primary);
  letter-spacing: 2px;
  margin-bottom: 12px;
  display: block;
}

.section-title {
  font-size: 2.6rem;
  font-weight: 800;
  letter-spacing: -1px;
  margin-bottom: 16px;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-sub);
}

/* 8. 核心优势 细节风格全面增强 */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 24px;
  padding: 42px 32px;
  transition: var(--transition-normal);
  position: relative;
  overflow: hidden;
  backdrop-filter: blur(14px);
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; width: 100%; height: 100%;
  background: radial-gradient(circle at top left, rgba(0, 242, 254, 0.12), transparent 60%);
  opacity: 0;
  transition: var(--transition-fast);
}

.feature-card:hover {
  transform: translateY(-8px);
  background: var(--bg-card-hover);
  border-color: rgba(0, 242, 254, 0.4);
  box-shadow: 0 20px 45px -10px rgba(0, 0, 0, 0.7), 0 0 30px rgba(0, 242, 254, 0.15);
}

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

.feature-icon-wrapper {
  width: 70px;
  height: 70px;
  background: linear-gradient(135deg, rgba(0, 242, 254, 0.15) 0%, rgba(79, 172, 254, 0.15) 100%);
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 28px;
  border: 1px solid rgba(0, 242, 254, 0.3);
  color: var(--primary);
  box-shadow: 0 8px 20px rgba(0, 242, 254, 0.2);
  transition: var(--transition-normal);
}

.feature-card:hover .feature-icon-wrapper {
  transform: scale(1.1) rotate(4deg);
  background: var(--primary-gradient);
  color: #040810;
  box-shadow: 0 0 30px rgba(0, 242, 254, 0.6);
}

.feature-title {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 14px;
  color: var(--text-main);
}

.feature-desc {
  color: var(--text-sub);
  font-size: 0.98rem;
  line-height: 1.7;
}

/* 9. 流媒体与 AI 支持图卡 品牌配色高亮增强 */
.support-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.support-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 22px;
  padding: 32px 24px;
  text-align: center;
  transition: var(--transition-normal);
  backdrop-filter: blur(12px);
  position: relative;
  overflow: hidden;
}

.support-card:hover {
  transform: translateY(-6px) scale(1.02);
  background: rgba(24, 30, 44, 0.9);
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.5);
}

/* 品牌专属 Glow 悬浮配色 */
.support-card.netflix:hover { border-color: rgba(229, 9, 20, 0.6); box-shadow: 0 0 30px rgba(229, 9, 20, 0.3); }
.support-card.chatgpt:hover { border-color: rgba(16, 163, 127, 0.6); box-shadow: 0 0 30px rgba(16, 163, 127, 0.3); }
.support-card.claude:hover { border-color: rgba(217, 119, 6, 0.6); box-shadow: 0 0 30px rgba(217, 119, 6, 0.3); }
.support-card.youtube:hover { border-color: rgba(255, 0, 0, 0.6); box-shadow: 0 0 30px rgba(255, 0, 0, 0.3); }
.support-card.disney:hover { border-color: rgba(59, 130, 246, 0.6); box-shadow: 0 0 30px rgba(59, 130, 246, 0.3); }
.support-card.midjourney:hover { border-color: rgba(168, 85, 247, 0.6); box-shadow: 0 0 30px rgba(168, 85, 247, 0.3); }
.support-card.spotify:hover { border-color: rgba(34, 197, 94, 0.6); box-shadow: 0 0 30px rgba(34, 197, 94, 0.3); }
.support-card.tiktok:hover { border-color: rgba(236, 72, 153, 0.6); box-shadow: 0 0 30px rgba(236, 72, 153, 0.3); }

.support-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 18px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition-fast);
}

.support-card:hover .support-icon {
  transform: scale(1.12);
}

.support-name {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.support-tag {
  font-size: 0.8rem;
  color: var(--text-sub);
  background: rgba(255, 255, 255, 0.05);
  padding: 4px 12px;
  border-radius: 12px;
  display: inline-block;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

/* 10. 真实机场/代理套餐价格表 */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 24px;
  padding: 36px 24px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition-normal);
  position: relative;
  backdrop-filter: blur(14px);
}

.pricing-card.popular {
  background: linear-gradient(180deg, rgba(20, 32, 54, 0.95) 0%, rgba(10, 16, 28, 0.95) 100%);
  border: 2px solid var(--primary);
  box-shadow: 0 0 40px rgba(0, 242, 254, 0.25);
  transform: translateY(-8px);
}

.pricing-badge {
  position: absolute;
  top: -14px;
  right: 20px;
  background: var(--primary-gradient);
  color: #040810;
  font-weight: 800;
  font-size: 0.75rem;
  padding: 5px 14px;
  border-radius: 20px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.pricing-header {
  margin-bottom: 24px;
}

.plan-name {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.plan-desc {
  font-size: 0.85rem;
  color: var(--text-sub);
  min-height: 40px;
}

.plan-price {
  margin: 20px 0;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.price-currency {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--primary);
}

.price-amount {
  font-size: 3rem;
  font-weight: 900;
  color: var(--text-main);
  line-height: 1;
}

.price-period {
  font-size: 0.85rem;
  color: var(--text-sub);
}

.plan-features {
  margin-bottom: 30px;
  flex-grow: 1;
}

.plan-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
  color: var(--text-main);
  margin-bottom: 12px;
}

.check-icon {
  width: 16px;
  height: 16px;
  color: var(--primary);
  flex-shrink: 0;
}

.pricing-card .btn-primary,
.pricing-card .btn-secondary {
  width: 100%;
  text-align: center;
}

/* 10.5 30篇 SEO 文章卡片板块 (图卡) */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition-normal);
  backdrop-filter: blur(12px);
  position: relative;
  overflow: hidden;
}

.article-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-glow);
  box-shadow: var(--shadow-glow);
  background: var(--bg-card-hover);
}

.article-tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 14px;
}

.article-tag {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--primary);
  background: rgba(0, 242, 254, 0.1);
  border: 1px solid rgba(0, 242, 254, 0.2);
  padding: 3px 10px;
  border-radius: 12px;
}

.article-card-title {
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 12px;
  color: var(--text-main);
  transition: color var(--transition-fast);
}

.article-card:hover .article-card-title {
  color: var(--primary);
}

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

.article-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 16px;
}

.article-link-btn {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* 11. 用户评价 */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 30px;
  backdrop-filter: blur(10px);
}

.review-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}

.avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, #1e293b 0%, #334155 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: var(--primary);
  border: 1px solid var(--border-glow);
}

.user-info .user-name {
  font-weight: 700;
  font-size: 1rem;
}

.user-info .user-title {
  font-size: 0.8rem;
  color: var(--text-sub);
}

.rating-stars {
  color: #fbbf24;
  margin-bottom: 14px;
  font-size: 0.9rem;
}

.review-text {
  color: var(--text-sub);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* 12. FAQ (常见问题解答) */
.faq-list {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 18px;
  overflow: hidden;
  transition: var(--transition-fast);
}

.faq-question {
  padding: 24px 28px;
  font-size: 1.1rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  user-select: none;
}

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

.faq-toggle {
  width: 24px;
  height: 24px;
  transition: transform var(--transition-fast);
  color: var(--primary);
}

.faq-item.active .faq-toggle {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  padding: 0 28px;
  color: var(--text-sub);
  font-size: 0.95rem;
  line-height: 1.7;
  transition: all 0.3s cubic-bezier(0, 1, 0, 1);
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding: 0 28px 24px;
  transition: all 0.3s cubic-bezier(1, 0, 1, 0);
}

/* 13. 右侧吸附侧边箭头导航 */
.section-nav-arrows {
  position: fixed;
  right: 24px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 9999;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  background: rgba(12, 16, 24, 0.88);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 30px;
  padding: 12px 8px;
  backdrop-filter: blur(16px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.6);
  transition: opacity var(--transition-fast);
}

.nav-arrow-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--text-main);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  outline: none;
}

.nav-arrow-btn:hover {
  background: var(--primary-gradient);
  color: #040810;
  border-color: transparent;
  box-shadow: 0 0 20px rgba(0, 242, 254, 0.6);
  transform: scale(1.1);
}

.nav-arrow-btn:active {
  transform: scale(0.95);
}

.nav-arrow-btn.disabled {
  opacity: 0.3;
  cursor: not-allowed;
  pointer-events: none;
}

.nav-indicator {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--primary);
  padding: 4px 0;
  user-select: none;
}

/* 14. 页脚 Footer */
.footer {
  background: #040609;
  border-top: 1px solid var(--border-color);
  padding: 60px 0 40px;
  text-align: center;
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 40px;
  margin-bottom: 30px;
  flex-wrap: wrap;
}

.footer-nav-item {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-sub);
  transition: color var(--transition-fast);
  position: relative;
}

.footer-nav-item:hover {
  color: var(--primary);
}

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

/* 15. 响应式适配 */
@media (max-width: 1200px) {
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 1024px) {
  .header-nav {
    display: none;
  }
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .features-grid,
  .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .support-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  section {
    padding: 70px 0;
  }

  .hero {
    padding-top: 130px;
    padding-bottom: 70px;
  }

  .hero-title {
    font-size: 2.3rem;
    letter-spacing: -0.5px;
  }

  .hero-subtitle {
    font-size: 1rem;
    margin-bottom: 30px;
  }

  .hero-actions {
    flex-direction: column;
    width: 100%;
    gap: 14px;
  }

  .hero-actions .btn-primary,
  .hero-actions .btn-secondary,
  .hero-actions .btn-accent {
    width: 100%;
  }

  .hero-stats {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .features-grid,
  .pricing-grid,
  .reviews-grid,
  .support-grid,
  .articles-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .pricing-card.popular {
    transform: none;
  }

  .footer-nav {
    flex-direction: column;
    gap: 20px;
  }
}