@charset "UTF-8";

/* ==========================================================================
   WESTDATA - 快如闪电的全球边缘网络
   Pure CSS - 高性能极简原生样式表 (零外部框架，秒开体验)
   ========================================================================== */

:root {
  --brand: #2544c5;
  --brand-hover: #1b2ea8;
  --brand-light: #eef2ff;
  --brand-glow: rgba(37, 68, 197, 0.15);
  --brand-gradient: linear-gradient(135deg, #2544c5 0%, #1b2ea8 100%);
  --accent-orange: #f59e0b;
  --accent-green: #10b981;
  
  --text-900: #0f172a;
  --text-700: #334155;
  --text-600: #475569;
  --text-400: #94a3b8;
  
  --bg-white: #ffffff;
  --bg-50: #f8fafc;
  --bg-100: #f1f5f9;
  --border-color: #e2e8f0;
  
  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.25rem;
  --radius-full: 9999px;
  
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.06);
  --shadow-soft: 0 10px 30px rgba(37, 68, 197, 0.12);
  --shadow-hover: 0 16px 36px rgba(37, 68, 197, 0.18);
  
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

/* 基础重置与规范 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
  color: var(--text-900);
  background-color: var(--bg-white);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
}

img, picture, svg {
  display: block;
  max-width: 100%;
}

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

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

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

/* 布局容器 */
.container {
  width: 100%;
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 20px;
  padding-right: 20px;
}

.section {
  padding: 80px 0;
  position: relative;
}

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

.section-header {
  margin-bottom: 52px;
}

.section-tag {
  display: inline-block;
  padding: 4px 14px;
  background: var(--brand-light);
  color: var(--brand);
  font-size: 0.85rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  margin-bottom: 12px;
  letter-spacing: 0.5px;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--text-900);
  line-height: 1.25;
  margin-bottom: 14px;
  letter-spacing: -0.5px;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-600);
  max-width: 680px;
  margin-left: auto;
  margin-right: auto;
}

/* 顶部导航栏 (Navbar) */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  height: 72px;
  display: flex;
  align-items: center;
  transition: background var(--transition-fast), border-color var(--transition-fast);
}

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

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  cursor: pointer;
}

.brand-logo-img {
  max-height: 44px;
  width: auto;
  transition: transform var(--transition-normal);
}

.brand-logo-img:hover {
  transform: scale(1.04);
}

.brand-logo-img:active {
  transform: scale(0.96);
}

.nav-menu {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 28px;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-700);
  padding: 6px 0;
  position: relative;
  transition: color var(--transition-fast);
}

.nav-link:hover {
  color: var(--brand);
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--brand);
  transition: width var(--transition-fast);
}

.nav-link:hover::after {
  width: 100%;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* 通用按钮系统 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  padding: 10px 22px;
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
  text-decoration: none;
  white-space: nowrap;
  box-sizing: border-box;
}

.btn-sm {
  padding: 7px 16px;
  font-size: 0.875rem;
  border-radius: var(--radius-sm);
}

.btn-lg {
  padding: 14px 30px;
  font-size: 1.05rem;
  border-radius: var(--radius-lg);
}

.btn-brand {
  background: var(--brand);
  color: #ffffff;
  border: 1px solid var(--brand);
  box-shadow: 0 4px 14px rgba(37, 68, 197, 0.28);
}

.btn-brand:hover {
  background: var(--brand-hover);
  border-color: var(--brand-hover);
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(37, 68, 197, 0.36);
}

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

.btn-recommend {
  background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
  color: #ffffff;
  border: 1px solid #d97706;
  box-shadow: 0 4px 14px rgba(245, 158, 11, 0.25);
  font-weight: 700;
}

.btn-recommend:hover {
  background: linear-gradient(135deg, #d97706 0%, #b45309 100%);
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(245, 158, 11, 0.35);
}

.btn-outline {
  background: transparent;
  color: var(--brand);
  border: 1px solid var(--brand);
}

.btn-outline:hover {
  background: var(--brand-light);
  color: var(--brand-hover);
  border-color: var(--brand-hover);
}

.btn-ghost {
  background: var(--bg-100);
  color: var(--text-700);
}

.btn-ghost:hover {
  background: #e2e8f0;
  color: var(--text-900);
}

/* Hero 主视觉区 */
.hero {
  padding: 80px 0 90px;
  background: radial-gradient(1200px 480px at 10% 0%, rgba(37, 68, 197, 0.18), transparent 60%),
              radial-gradient(900px 420px at 90% 10%, rgba(27, 46, 168, 0.16), transparent 60%),
              linear-gradient(180deg, #f6f8ff 0%, #ffffff 85%);
  position: relative;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  align-items: center;
}

.hero-content {
  max-width: 620px;
}

.hero-badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--brand);
  background: #ffffff;
  border: 1px solid rgba(37, 68, 197, 0.25);
  padding: 6px 14px;
  border-radius: var(--radius-full);
  margin-bottom: 20px;
  box-shadow: 0 2px 8px rgba(37, 68, 197, 0.08);
}

.badge-dot {
  width: 8px;
  height: 8px;
  background: var(--accent-green);
  border-radius: 50%;
  animation: pulse-dot 2s infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.8); }
}

.hero-title {
  font-size: 2.85rem;
  font-weight: 900;
  line-height: 1.2;
  color: var(--text-900);
  margin-bottom: 18px;
  letter-spacing: -0.8px;
}

.hero-title .brand-highlight {
  color: var(--brand);
  background: linear-gradient(120deg, #2544c5, #4f46e5);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-700);
  line-height: 1.45;
  margin-bottom: 12px;
}

.hero-desc {
  font-size: 1.05rem;
  color: var(--text-600);
  line-height: 1.6;
  margin-bottom: 28px;
}

.hero-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 32px;
}

.hero-trust-list {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  font-size: 0.875rem;
  color: var(--text-600);
}

.trust-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.trust-icon {
  color: var(--brand);
  font-weight: bold;
}

/* Hero 右侧动态卡片与主图 */
.hero-visual {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.hero-banner-box {
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-soft);
  border: 1px solid rgba(255, 255, 255, 0.8);
  background: #ffffff;
  position: relative;
  transition: transform var(--transition-normal);
}

.hero-banner-box:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}

.hero-banner-box img {
  width: 100%;
  height: 270px;
  object-fit: cover;
}

/* 动态测速仪小组件 */
.speed-test-widget {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 18px 22px;
  box-shadow: var(--shadow-md);
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  position: relative;
  z-index: 2;
}

.speed-metric {
  text-align: center;
}

.speed-label {
  font-size: 0.75rem;
  color: var(--text-600);
  margin-bottom: 4px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.speed-value {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-900);
}

.speed-value.green {
  color: var(--accent-green);
}

.speed-value.blue {
  color: var(--brand);
}

.status-live-badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-green);
  background: rgba(16, 185, 129, 0.1);
  padding: 2px 8px;
  border-radius: var(--radius-full);
  margin-top: 2px;
}

/* 核心优势卡片 (3个图文卡片) */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 36px 28px;
  transition: all var(--transition-normal);
  position: relative;
  display: flex;
  flex-direction: column;
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(37, 68, 197, 0.4);
}

.feature-icon-badge {
  width: 58px;
  height: 58px;
  border-radius: var(--radius-lg);
  background: var(--brand-light);
  color: var(--brand);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  margin-bottom: 22px;
  transition: all var(--transition-fast);
}

.feature-card:hover .feature-icon-badge {
  background: var(--brand);
  color: #ffffff;
  transform: scale(1.08);
}

.feature-card h3 {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-900);
  margin-bottom: 12px;
}

.feature-card p {
  font-size: 0.95rem;
  color: var(--text-600);
  line-height: 1.65;
  margin-bottom: 16px;
}

.feature-tags {
  margin-top: auto;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.feature-tag-chip {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--brand);
  background: rgba(37, 68, 197, 0.08);
  padding: 3px 8px;
  border-radius: 4px;
}

/* 流媒体与 AI 支持图卡 */
.streaming-ai-section {
  background: var(--bg-50);
}

.services-showcase-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 36px;
}

.service-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 22px;
  display: flex;
  align-items: center;
  gap: 16px;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-sm);
}

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

.service-icon-wrap {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  background: var(--bg-100);
  flex-shrink: 0;
}

.service-info h4 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-900);
  margin-bottom: 3px;
}

.service-info p {
  font-size: 0.8rem;
  color: var(--text-600);
}

.service-badge {
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--accent-green);
  background: rgba(16, 185, 129, 0.12);
  padding: 2px 6px;
  border-radius: 4px;
  display: inline-block;
  margin-top: 4px;
}

.streaming-banner-info {
  background: #ffffff;
  border: 1px solid rgba(37, 68, 197, 0.2);
  border-radius: var(--radius-xl);
  padding: 24px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  box-shadow: var(--shadow-sm);
}

.streaming-banner-text {
  font-size: 0.95rem;
  color: var(--text-700);
}

.streaming-banner-text strong {
  color: var(--brand);
}

/* 套餐价格对比表 (Pricing) */
.pricing-section {
  position: relative;
}

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

.pricing-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 38px 28px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all var(--transition-normal);
}

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

.pricing-card.popular {
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(37, 68, 197, 0.12), var(--shadow-soft);
  background: #ffffff;
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--brand);
  color: #ffffff;
  font-size: 0.8rem;
  font-weight: 700;
  padding: 4px 18px;
  border-radius: var(--radius-full);
  box-shadow: 0 4px 12px rgba(37, 68, 197, 0.3);
}

.plan-type-pill {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-600);
  background: var(--bg-100);
  padding: 3px 10px;
  border-radius: var(--radius-full);
  margin-bottom: 12px;
  align-self: flex-start;
}

.pricing-card h3 {
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--text-900);
  margin-bottom: 8px;
}

.plan-desc {
  font-size: 0.875rem;
  color: var(--text-600);
  margin-bottom: 18px;
}

.plan-price {
  font-size: 2.4rem;
  font-weight: 900;
  color: var(--text-900);
  margin-bottom: 24px;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.price-currency {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--brand);
}

.price-unit {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-600);
}

.features-list {
  list-style: none;
  margin-bottom: 28px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  flex-grow: 1;
}

.feature-li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.9rem;
  color: var(--text-700);
}

.check-icon {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--brand-light);
  color: var(--brand);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 800;
  flex-shrink: 0;
}

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

/* SEO 专栏与文章展示 (位于价格板块下方) */
.seo-articles-section {
  background: var(--bg-50);
  padding: 84px 0;
}

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

.article-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 26px;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-sm);
  position: relative;
}

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

.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 12px;
}

.article-category {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--brand);
  background: var(--brand-light);
  padding: 3px 10px;
  border-radius: var(--radius-full);
}

.article-date {
  font-size: 0.75rem;
  color: var(--text-400);
}

.article-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.45;
  margin-bottom: 10px;
  color: var(--text-900);
}

.article-card h3 a {
  color: inherit;
  transition: color var(--transition-fast);
}

.article-card h3 a:hover {
  color: var(--brand);
}

.article-summary {
  font-size: 0.875rem;
  color: var(--text-600);
  line-height: 1.6;
  margin-bottom: 18px;
  flex-grow: 1;
}

.article-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-color);
  padding-top: 14px;
}

.article-read-btn {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--brand);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.article-read-btn:hover {
  gap: 8px;
}

.article-aff-btn {
  font-size: 0.8rem;
  font-weight: 600;
  padding: 5px 12px;
  background: var(--bg-100);
  color: var(--text-700);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.article-aff-btn:hover {
  background: var(--brand);
  color: #ffffff;
}

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

.review-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 26px;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
}

.review-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-soft);
}

.review-stars {
  color: #f59e0b;
  margin-bottom: 12px;
  font-size: 1rem;
}

.review-text {
  font-size: 0.95rem;
  color: var(--text-700);
  line-height: 1.6;
  margin-bottom: 18px;
  flex-grow: 1;
  font-style: italic;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 12px;
}

.author-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--brand-light);
  color: var(--brand);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
}

.author-name {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-900);
}

.author-role {
  font-size: 0.75rem;
  color: var(--text-600);
}

/* 全球优选节点 (Nodes) */
.nodes-section {
  background: var(--bg-50);
}

.nodes-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 16px;
  margin-bottom: 24px;
}

.node-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 16px 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  transition: all var(--transition-fast);
  text-align: center;
}

.node-card:hover {
  transform: translateY(-3px);
  border-color: var(--brand);
  box-shadow: var(--shadow-sm);
}

.node-flag-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.node-flag {
  width: 24px;
  height: 16px;
  border-radius: 2px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.15);
}

.node-name {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-900);
}

.node-ping {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-green);
  background: rgba(16, 185, 129, 0.1);
  padding: 2px 8px;
  border-radius: var(--radius-full);
}

.nodes-alert {
  background: var(--brand-light);
  border: 1px solid rgba(37, 68, 197, 0.2);
  color: var(--brand-hover);
  border-radius: var(--radius-md);
  padding: 14px 20px;
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 10px;
}

/* 全平台客户端 (Download) */
.download-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
}

.download-platforms {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.download-stat-box {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 32px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  box-shadow: var(--shadow-soft);
}

.stat-item {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 18px;
  background: var(--bg-50);
}

.stat-item-label {
  font-size: 0.8rem;
  color: var(--text-600);
  margin-bottom: 4px;
}

.stat-item-val {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--brand);
}

/* 常见问题 (FAQ) */
.faq-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.faq-column {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}

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

.faq-header {
  padding: 18px 22px;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-900);
  text-align: left;
  background: #ffffff;
}

.faq-toggle-icon {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--bg-100);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  color: var(--text-600);
  transition: transform var(--transition-fast);
  flex-shrink: 0;
}

.faq-item.active .faq-toggle-icon {
  transform: rotate(180deg);
  background: var(--brand);
  color: #ffffff;
}

.faq-body {
  padding: 0 22px 18px;
  font-size: 0.925rem;
  color: var(--text-600);
  line-height: 1.65;
  display: none;
}

.faq-item.active .faq-body {
  display: block;
}

/* 底部 CTA 激励区 */
.cta-banner-section {
  padding: 60px 0;
}

.cta-box {
  background: radial-gradient(800px 400px at 50% 0%, rgba(37, 68, 197, 0.15), transparent 70%),
              #ffffff;
  border: 1px solid rgba(37, 68, 197, 0.25);
  border-radius: var(--radius-xl);
  padding: 56px 36px;
  text-align: center;
  box-shadow: var(--shadow-soft);
}

.cta-box h2 {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 12px;
}

.cta-box p {
  font-size: 1.05rem;
  color: var(--text-600);
  margin-bottom: 28px;
}

.cta-buttons {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* 页脚 (Footer) - 严格遵循指令 */
.site-footer {
  border-top: 1px solid var(--border-color);
  padding: 44px 0 32px;
  background: #ffffff;
}

.footer-nav {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 36px;
  margin-bottom: 24px;
}

.footer-nav a {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-700);
  transition: color var(--transition-fast);
}

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

.footer-pbn-statement {
  text-align: center;
  font-size: 0.875rem;
  color: var(--text-600);
  margin-bottom: 18px;
  line-height: 1.7;
}

.footer-pbn-link {
  font-weight: 700;
  color: var(--brand);
  text-decoration: underline;
  margin: 0 4px;
}

.footer-pbn-link:hover {
  color: var(--brand-hover);
}

.footer-copyright {
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-400);
}

/* ==========================================================================
   右侧章节悬浮上下翻页器 (Interactive Chapter Navigator)
   ========================================================================== */
.chapter-nav-floating {
  position: fixed;
  right: 20px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 999;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.nav-arrow-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: #ffffff;
  border: 1px solid var(--border-color);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
  color: var(--text-700);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  transition: all var(--transition-fast);
  outline: none;
}

.nav-arrow-btn:hover {
  background: var(--brand);
  color: #ffffff;
  border-color: var(--brand);
  transform: scale(1.1);
  box-shadow: 0 6px 20px rgba(37, 68, 197, 0.35);
}

.nav-arrow-btn:active {
  transform: scale(0.92);
}

.nav-arrow-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none;
}

/* ==========================================================================
   文章详情页面的专属排版 (Article Page Styling)
   ========================================================================== */
.article-header {
  padding: 60px 0 40px;
  background: linear-gradient(180deg, #f6f8ff 0%, #ffffff 100%);
  border-bottom: 1px solid var(--border-color);
}

.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-600);
  margin-bottom: 16px;
}

.article-title-single {
  font-size: 2.3rem;
  font-weight: 800;
  line-height: 1.3;
  color: var(--text-900);
  margin-bottom: 16px;
}

.article-meta-single {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.85rem;
  color: var(--text-600);
}

.article-body-content {
  max-width: 860px;
  margin: 40px auto;
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--text-900);
}

.article-body-content h2 {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-900);
  margin-top: 40px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--brand-light);
}

.article-body-content h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-900);
  margin-top: 28px;
  margin-bottom: 12px;
}

.article-body-content p {
  margin-bottom: 20px;
  color: var(--text-700);
}

.article-body-content ul, .article-body-content ol {
  margin-bottom: 24px;
  padding-left: 24px;
}

.article-body-content li {
  margin-bottom: 8px;
  color: var(--text-700);
}

.article-cta-box {
  background: linear-gradient(135deg, rgba(37, 68, 197, 0.08) 0%, rgba(37, 68, 197, 0.03) 100%);
  border: 1px solid rgba(37, 68, 197, 0.25);
  border-radius: var(--radius-lg);
  padding: 30px;
  margin: 36px 0;
  text-align: center;
}

.article-cta-box h3 {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-900);
  margin-top: 0;
  margin-bottom: 10px;
}

.article-cta-box p {
  font-size: 0.95rem;
  color: var(--text-600);
  margin-bottom: 20px;
}

.article-table {
  width: 100%;
  border-collapse: collapse;
  margin: 28px 0;
  font-size: 0.95rem;
}

.article-table th, .article-table td {
  border: 1px solid var(--border-color);
  padding: 12px 16px;
  text-align: left;
}

.article-table th {
  background: var(--bg-100);
  font-weight: 700;
}

/* ==========================================================================
   深色模式支持 (@media prefers-color-scheme: dark)
   ========================================================================== */
@media (prefers-color-scheme: dark) {
  :root {
    --text-900: #f8fafc;
    --text-700: #e2e8f0;
    --text-600: #94a3b8;
    --text-400: #64748b;
    --bg-white: #0b1220;
    --bg-50: #0f172a;
    --bg-100: #1e293b;
    --border-color: rgba(148, 163, 184, 0.2);
  }

  body {
    background-color: var(--bg-white);
    color: var(--text-900);
  }

  .navbar {
    background: rgba(11, 18, 32, 0.92);
    border-color: var(--border-color);
  }

  .nav-link {
    color: #cbd5e1;
  }

  .hero {
    background: radial-gradient(1200px 480px at 10% 0%, rgba(79, 121, 255, 0.22), transparent 60%),
                radial-gradient(900px 420px at 90% 10%, rgba(55, 80, 200, 0.2), transparent 60%),
                linear-gradient(180deg, #111c34 0%, #0b1220 85%);
  }

  .hero-badge-pill {
    background: #1e293b;
    border-color: rgba(148, 163, 184, 0.3);
    color: #93b4ff;
  }

  .hero-banner-box {
    background: #1e293b;
    border-color: var(--border-color);
  }

  .speed-test-widget,
  .feature-card,
  .service-card,
  .pricing-card,
  .article-card,
  .review-card,
  .node-card,
  .download-stat-box,
  .stat-item,
  .faq-item,
  .faq-header,
  .cta-box,
  .site-footer {
    background: #141f38 !important;
    border-color: var(--border-color);
  }

  .feature-icon-badge,
  .service-icon-wrap,
  .author-avatar,
  .faq-toggle-icon {
    background: rgba(99, 102, 241, 0.18) !important;
    color: #93b4ff !important;
  }

  .pricing-card.popular {
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.25);
  }

  .nav-arrow-btn {
    background: #141f38;
    color: #e2e8f0;
    border-color: var(--border-color);
  }

  .article-header {
    background: #0f172a;
    border-color: var(--border-color);
  }

  .article-body-content h2 {
    border-bottom-color: rgba(148, 163, 184, 0.2);
  }

  .article-table th {
    background: #1e293b;
  }
}

/* ==========================================================================
   响应式设计与媒体查询 (@media) - 确保手机端完美单栏与手指触摸体验
   ========================================================================== */
@media (max-width: 992px) {
  .hero-grid,
  .download-grid {
    grid-template-columns: 1fr;
    gap: 36px;
  }

  .hero-visual {
    order: -1;
  }

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

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

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

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

  .nav-menu {
    display: none; /* 极简响应式，手机端聚焦转化按钮 */
  }

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

  .section-title {
    font-size: 1.85rem;
  }

  .chapter-nav-floating {
    right: 12px;
  }

  .nav-arrow-btn {
    width: 38px;
    height: 38px;
    font-size: 0.95rem;
  }
}

@media (max-width: 576px) {
  .section {
    padding: 56px 0;
  }

  .hero {
    padding: 48px 0 60px;
  }

  .hero-title {
    font-size: 1.85rem;
  }

  .hero-subtitle {
    font-size: 1.05rem;
  }

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

  .hero-buttons {
    flex-direction: column;
    width: 100%;
  }

  .hero-buttons .btn {
    width: 100%;
    justify-content: center;
  }

  .speed-test-widget {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .services-showcase-grid {
    grid-template-columns: 1fr;
  }

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

  .download-stat-box {
    grid-template-columns: 1fr;
  }

  .footer-nav {
    flex-direction: column;
    gap: 14px;
  }

  .streaming-banner-info {
    flex-direction: column;
    text-align: center;
  }
}