/* ==========================================================================
   星辰VPN (XingChen VPN) - Minimalist Light Nebula Mesh & Modern Editorial SaaS
   配色：纯白画布 (#FFFFFF), 深石板炭灰 (#0F172A), 柔和石板灰 (#475569), 
   主色星光靛蓝 (#4F46E5), 辅色晴空青蓝 (#0EA5E9), 星云淡紫 (#EEF2FF), 冰蓝 (#E0F2FE)
   ========================================================================== */

:root {
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  
  /* 白天模式颜色 (默认) */
  --bg-canvas: #ffffff;
  --bg-subtle: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-hover: #fcfdfe;
  --bg-glass: rgba(255, 255, 255, 0.85);
  
  --text-main: #0f172a;       /* Deep navy charcoal */
  --text-muted: #475569;      /* Muted slate subtext */
  --text-light: #94a3b8;
  
  --primary: #4f46e5;         /* Starlight indigo */
  --primary-hover: #4338ca;
  --primary-light: #eef2ff;   /* Nebula lavender */
  --secondary: #0ea5e9;       /* Sky cyan */
  --secondary-hover: #0284c7;
  --secondary-light: #e0f2fe; /* Ice blue */
  
  --border-color: #e2e8f0;
  --border-light: #f1f5f9;
  --border-focus: #c7d2fe;
  
  /* 阴影系统 */
  --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.04), 0 1px 2px rgba(15, 23, 42, 0.02);
  --shadow-md: 0 4px 12px -2px rgba(15, 23, 42, 0.06), 0 2px 6px -1px rgba(15, 23, 42, 0.03);
  --shadow-lg: 0 16px 32px -6px rgba(79, 70, 229, 0.08), 0 6px 16px -4px rgba(15, 23, 42, 0.04);
  --shadow-card-hover: 0 20px 35px -8px rgba(14, 165, 233, 0.12), 0 8px 16px -4px rgba(79, 70, 229, 0.06);

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 夜间模式 */
[data-theme="dark"] {
  --bg-canvas: #090d16;
  --bg-subtle: #0f172a;
  --bg-card: #131b2e;
  --bg-card-hover: #17223b;
  --bg-glass: rgba(9, 13, 22, 0.88);
  
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-light: #64748b;
  
  --primary: #6366f1;
  --primary-hover: #818cf8;
  --primary-light: rgba(99, 102, 241, 0.15);
  --secondary: #38bdf8;
  --secondary-hover: #7dd3fc;
  --secondary-light: rgba(56, 189, 248, 0.15);
  
  --border-color: #1e293b;
  --border-light: #283548;
  --border-focus: #3730a3;
  
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.45);
  --shadow-lg: 0 16px 32px rgba(0, 0, 0, 0.6);
  --shadow-card-hover: 0 20px 40px rgba(99, 102, 241, 0.15);
}

/* 全局重置 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-canvas);
  color: var(--text-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--transition), color var(--transition);
  overflow-x: hidden;
  position: relative;
}

/* 星云背景光晕效果 (Nebula Mesh) */
.nebula-glow-tr {
  position: absolute;
  top: 0;
  right: 0;
  width: 550px;
  height: 550px;
  background: radial-gradient(circle at 80% 20%, var(--secondary-light) 0%, rgba(224, 242, 254, 0) 70%);
  pointer-events: none;
  z-index: 0;
  filter: blur(40px);
}

.nebula-glow-bl {
  position: absolute;
  top: 180px;
  left: 0;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle at 20% 40%, var(--primary-light) 0%, rgba(238, 242, 255, 0) 70%);
  pointer-events: none;
  z-index: 0;
  filter: blur(50px);
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}

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

/* ==========================================================================
   导航栏 Header (Sticky Navbar)
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: var(--bg-glass);
  border-bottom: 1px solid var(--border-color);
  transition: background-color var(--transition), border-color var(--transition);
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

/* 品牌官方 Logo 样式 */
.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--text-main);
  text-decoration: none;
}

.brand-logo-img {
  height: 34px;
  width: auto;
  display: block;
  object-fit: contain;
  transition: transform var(--transition-fast);
}

.brand-logo:hover .brand-logo-img {
  transform: scale(1.03);
}

.brand-logo-dark {
  display: none;
}

[data-theme="dark"] .brand-logo-light {
  display: none;
}

[data-theme="dark"] .brand-logo-dark {
  display: block;
}

/* 导航链接与动态滑动下划线 */
.nav-menu {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
  position: relative;
  padding: 6px 0;
  transition: color var(--transition-fast);
}

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

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0%;
  height: 2px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  transition: width 0.3s ease, left 0.3s ease;
  border-radius: 2px;
}

.nav-link:hover::after {
  width: 100%;
  left: 0;
}

/* 特别突出“推荐资讯”入口 */
.nav-badge-new {
  font-size: 0.68rem;
  background: var(--secondary-light);
  color: var(--secondary);
  font-weight: 700;
  padding: 1px 6px;
  border-radius: var(--radius-full);
  margin-left: 4px;
  vertical-align: middle;
}

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

/* 中英文语言切换胶囊按钮 (Pill-shaped Lang Switcher) */
.lang-switcher {
  display: inline-flex;
  align-items: center;
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  padding: 3px 10px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  transition: var(--transition-fast);
  user-select: none;
}

.lang-switcher:hover {
  border-color: var(--primary);
  color: var(--text-main);
}

.lang-switcher .active {
  color: var(--primary);
  font-weight: 700;
}

/* 精致透明昼夜模式切换按钮 */
.theme-toggle-btn {
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  width: 38px;
  height: 38px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition-fast);
}

.theme-toggle-btn:hover {
  border-color: var(--primary);
  background: var(--primary-light);
  color: var(--primary);
  transform: rotate(15deg);
}

.theme-icon {
  width: 19px;
  height: 19px;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  fill: none;
}

.icon-sun { display: none; }
[data-theme="dark"] .icon-sun { display: block; }
[data-theme="dark"] .icon-moon { display: none; }

/* 按钮通用 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  font-size: 0.94rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: var(--transition-fast);
  border: none;
  white-space: nowrap;
}

.btn-indigo {
  background-color: var(--primary);
  color: #ffffff !important;
  box-shadow: 0 4px 14px rgba(79, 70, 229, 0.25);
}

.btn-indigo:hover {
  background-color: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(79, 70, 229, 0.35);
}

.btn-cyan {
  background-color: var(--secondary);
  color: #ffffff !important;
  box-shadow: 0 4px 14px rgba(14, 165, 233, 0.22);
}

.btn-cyan:hover {
  background-color: var(--secondary-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(14, 165, 233, 0.32);
}

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

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

.btn-lg {
  padding: 13px 30px;
  font-size: 1.05rem;
}

/* ==========================================================================
   Hero 主视觉区
   ========================================================================== */
.hero-section {
  padding: 85px 0 60px;
  text-align: center;
  position: relative;
}

.hero-content {
  max-width: 880px;
  margin: 0 auto;
}

/* 顶部全平台极速专线胶囊徽章与信号波形 */
.hero-pill-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 18px;
  background: var(--primary-light);
  color: var(--primary);
  border: 1px solid rgba(79, 70, 229, 0.2);
  border-radius: var(--radius-full);
  font-size: 0.88rem;
  font-weight: 600;
  margin-bottom: 24px;
}

.signal-wave-icon {
  width: 16px;
  height: 16px;
  display: flex;
  align-items: center;
  gap: 2px;
}

.signal-bar {
  width: 3px;
  background-color: currentColor;
  border-radius: 2px;
}
.signal-bar:nth-child(1) { height: 6px; }
.signal-bar:nth-child(2) { height: 10px; }
.signal-bar:nth-child(3) { height: 14px; }
.signal-bar:nth-child(4) { height: 16px; }

/* 大标题与简介 */
.hero-title {
  font-size: 3.4rem;
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -1.2px;
  color: var(--text-main);
  margin-bottom: 20px;
}

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

.hero-subtitle {
  font-size: 1.18rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 36px;
  max-width: 740px;
  margin-left: auto;
  margin-right: auto;
}

/* 双色 CTA 按钮 */
.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 45px;
}

/* 3-Column Animated Metric Row */
.hero-metrics-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: 780px;
  margin: 0 auto 36px;
  padding: 18px 24px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.metric-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  border-right: 1px solid var(--border-color);
}

.metric-item:last-child {
  border-right: none;
}

.metric-number {
  font-size: 1.9rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.2;
}

.metric-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
  margin-top: 4px;
}

/* ==========================================================================
   Interactive Node Ping Strip (实时节点延迟交互条)
   ========================================================================== */
.ping-strip-container {
  max-width: 820px;
  margin: 0 auto;
}

.ping-strip {
  background: var(--bg-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  padding: 8px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: var(--shadow-sm);
}

.ping-strip-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-muted);
  padding-left: 8px;
}

.ping-pulse-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: #10b981;
  box-shadow: 0 0 8px #10b981;
  animation: pulse-ping 2s infinite;
}

@keyframes pulse-ping {
  0% { transform: scale(0.9); opacity: 0.6; }
  50% { transform: scale(1.2); opacity: 1; }
  100% { transform: scale(0.9); opacity: 0.6; }
}

.ping-regions-wrapper {
  display: flex;
  align-items: center;
  gap: 8px;
}

.ping-region-btn {
  background: transparent;
  border: 1px solid transparent;
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  transition: var(--transition-fast);
  display: flex;
  align-items: center;
  gap: 6px;
}

.ping-region-btn:hover {
  color: var(--text-main);
  background: var(--bg-subtle);
}

.ping-region-btn.active {
  background: var(--bg-canvas);
  color: var(--primary);
  border-color: var(--border-color);
  box-shadow: var(--shadow-sm);
}

.ping-val {
  font-family: monospace;
  font-size: 0.82rem;
  color: #10b981;
  font-weight: 700;
}

/* ==========================================================================
   Section 通用规范
   ========================================================================== */
.section-wrapper {
  padding: 85px 0;
  position: relative;
}

.section-subtle {
  background-color: var(--bg-subtle);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 52px;
}

.section-tag {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.2px;
  color: var(--primary);
  margin-bottom: 10px;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.8px;
  color: var(--text-main);
  margin-bottom: 14px;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* ==========================================================================
   产品核心优势 (Bento 风格 3个图文卡片 - 严格技术线条图标)
   ========================================================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-bento-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 36px 30px;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  display: flex;
  flex-direction: column;
  position: relative;
}

.feature-bento-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-card-hover);
  border-color: rgba(79, 70, 229, 0.4);
}

/* 技术线条图标容器 (Signal waveform, lock shield, server racks) */
.tech-icon-container {
  width: 54px;
  height: 54px;
  border-radius: var(--radius-md);
  background: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
}

.tech-icon-container svg {
  width: 26px;
  height: 26px;
  stroke-width: 2;
}

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

.feature-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.68;
  margin-bottom: 22px;
}

.feature-footer-tags {
  margin-top: auto;
  padding-top: 18px;
  border-top: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.feature-tag-line {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--text-main);
}

.feature-tag-line svg {
  width: 15px;
  height: 15px;
  color: var(--secondary);
  flex-shrink: 0;
}

/* ==========================================================================
   流媒体图卡 & AI 支持图卡
   ========================================================================== */
.services-split-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
}

.service-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 38px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

.service-card:hover {
  border-color: rgba(14, 165, 233, 0.4);
  box-shadow: var(--shadow-card-hover);
}

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

.service-icon-box {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.service-icon-box.stream {
  background: rgba(225, 29, 72, 0.1);
  color: #e11d48;
}

.service-icon-box.ai {
  background: rgba(14, 165, 233, 0.12);
  color: var(--secondary);
}

.service-icon-box svg {
  width: 26px;
  height: 26px;
}

.service-card-title {
  font-size: 1.38rem;
  font-weight: 700;
  color: var(--text-main);
}

.service-card-desc {
  font-size: 0.96rem;
  color: var(--text-muted);
  line-height: 1.68;
  margin-bottom: 26px;
}

.service-chips-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-bottom: 26px;
}

.service-chip {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-main);
}

.chip-status {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: #10b981;
}

.service-bottom-note {
  margin-top: auto;
  font-size: 0.85rem;
  color: var(--text-light);
  display: flex;
  align-items: center;
  gap: 6px;
}

/* ==========================================================================
   套餐价格对比表 (参考网上真实套餐价格)
   ========================================================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 38px 30px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: transform var(--transition), box-shadow var(--transition);
}

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

.pricing-card.featured {
  border: 2px solid var(--primary);
  box-shadow: 0 16px 36px -6px rgba(79, 70, 229, 0.2);
}

.popular-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #ffffff;
  font-size: 0.78rem;
  font-weight: 700;
  padding: 4px 16px;
  border-radius: var(--radius-full);
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.3);
}

.plan-name {
  font-size: 1.3rem;
  font-weight: 700;
  margin: 0 0 8px 0;
  line-height: 1.3;
  color: var(--text-main);
}

.plan-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  min-height: 42px;
  margin-bottom: 20px;
}

.plan-price-wrap {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-color);
}

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

.price-num {
  font-size: 3rem;
  font-weight: 900;
  letter-spacing: -1.2px;
  color: var(--text-main);
}

.price-cycle {
  font-size: 0.92rem;
  color: var(--text-muted);
}

.plan-features {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 13px;
  margin-bottom: 32px;
  flex-grow: 1;
}

.plan-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.92rem;
  color: var(--text-main);
}

.check-icon {
  width: 17px;
  height: 17px;
  color: #10b981;
  flex-shrink: 0;
}

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

/* ==========================================================================
   用户评价 (User Reviews)
   ========================================================================== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 30px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: var(--transition);
}

.review-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(79, 70, 229, 0.3);
}

.review-score-stars {
  display: flex;
  gap: 4px;
  color: #f59e0b;
  margin-bottom: 14px;
}

.review-score-stars svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

.review-body {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 22px;
}

.reviewer-meta {
  display: flex;
  align-items: center;
  gap: 12px;
}

.avatar-initial {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--primary-light);
  color: var(--primary);
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
}

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

.reviewer-title {
  font-size: 0.8rem;
  color: var(--text-light);
}

/* ==========================================================================
   常见问题解答 (FAQ)
   ========================================================================== */
.faq-accordion {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

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

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

.faq-question {
  width: 100%;
  background: none;
  border: none;
  text-align: left;
  padding: 22px 26px;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
}

.faq-icon {
  width: 20px;
  height: 20px;
  color: var(--text-muted);
  transition: transform 0.25s ease;
  flex-shrink: 0;
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s cubic-bezier(0, 1, 0, 1);
  background-color: var(--bg-subtle);
}

.faq-answer-inner {
  padding: 0 26px 22px;
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.7;
}

.faq-item.active .faq-icon {
  transform: rotate(180deg);
  color: var(--primary);
}

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

/* ==========================================================================
   页脚 Footer - 严格仅保留4个标题，且新页面打开
   ========================================================================== */
.site-footer {
  background-color: var(--bg-canvas);
  border-top: 1px solid var(--border-color);
  padding: 50px 0 35px;
  text-align: center;
}

.footer-nav-list {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 36px;
  list-style: none;
  margin-bottom: 28px;
}

.footer-nav-link {
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

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

.footer-copy {
  font-size: 0.86rem;
  color: var(--text-light);
  line-height: 1.6;
}

/* ==========================================================================
   深度 SEO 长文专页专属排版 (Article Layout & Typography)
   ========================================================================== */
.article-container {
  max-width: 900px;
  margin: 36px auto 80px;
  padding: 0 24px;
}

.article-main-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 52px;
  box-shadow: var(--shadow-sm);
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.86rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.breadcrumb a {
  color: var(--primary);
  text-decoration: none;
}

.breadcrumb a:hover {
  text-decoration: underline;
}

.article-header {
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 28px;
  margin-bottom: 36px;
}

.article-category-tag {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--primary);
  background: var(--primary-light);
  padding: 4px 14px;
  border-radius: var(--radius-full);
  margin-bottom: 16px;
}

.article-main-title {
  font-size: 2.3rem;
  font-weight: 900;
  line-height: 1.28;
  letter-spacing: -0.8px;
  color: var(--text-main);
  margin-bottom: 18px;
}

.article-meta-bar {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.88rem;
  color: var(--text-light);
  flex-wrap: wrap;
}

.article-meta-bar span {
  display: flex;
  align-items: center;
  gap: 6px;
}

/* 目录组件 (Table of Contents) */
.article-toc {
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-left: 4px solid var(--primary);
  border-radius: var(--radius-md);
  padding: 24px 28px;
  margin: 30px 0 40px;
}

.toc-title {
  font-size: 1.12rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.toc-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 0;
  padding: 0;
}

.toc-list li a {
  font-size: 0.94rem;
  color: var(--text-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
  display: flex;
  align-items: center;
  gap: 8px;
}

.toc-list li a:hover {
  color: var(--primary);
  text-decoration: underline;
}

/* 文章正文正规化排版 */
.article-body {
  color: var(--text-muted);
  font-size: 1.05rem;
  line-height: 1.85;
}

.article-body h2 {
  font-size: 1.65rem;
  font-weight: 800;
  color: var(--text-main);
  margin: 46px 0 18px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-color);
  letter-spacing: -0.5px;
}

.article-body h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin: 30px 0 12px;
}

.article-body p {
  margin-bottom: 20px;
}

.article-body ul, .article-body ol {
  margin: 0 0 24px 24px;
}

.article-body li {
  margin-bottom: 10px;
}

.article-body strong {
  color: var(--text-main);
}

.article-body a {
  color: var(--primary);
  text-decoration: underline;
  font-weight: 600;
}

.article-body a:hover {
  color: var(--secondary);
}

/* 引用提示框 (Callout Box) */
.article-callout {
  background: var(--primary-light);
  border-left: 4px solid var(--primary);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: 20px 24px;
  margin: 28px 0;
  color: var(--text-main);
}

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

/* 深度对比表格 (Comparison Table) */
.table-responsive {
  width: 100%;
  overflow-x: auto;
  margin: 28px 0;
}

.article-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.95rem;
}

.article-table th {
  background: var(--bg-subtle);
  color: var(--text-main);
  font-weight: 700;
  padding: 14px 18px;
  border: 1px solid var(--border-color);
}

.article-table td {
  padding: 14px 18px;
  border: 1px solid var(--border-color);
  color: var(--text-muted);
}

.article-table tr:hover td {
  background: var(--bg-subtle);
}

/* 文章内置 FAQ 模块 */
.article-faq-section {
  margin-top: 52px;
  padding-top: 36px;
  border-top: 2px dashed var(--border-color);
}

.article-faq-item {
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 22px 24px;
  margin-bottom: 18px;
}

.article-faq-item h4 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.article-faq-item p {
  margin-bottom: 0;
  font-size: 0.96rem;
  line-height: 1.7;
}

/* 相关阅读网格 (Related Articles Grid) */
.related-section {
  margin-top: 50px;
  padding-top: 36px;
  border-top: 1px solid var(--border-color);
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-top: 20px;
}

.related-card {
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  text-decoration: none;
  transition: var(--transition-fast);
  display: flex;
  flex-direction: column;
}

.related-card:hover {
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.related-card h4 {
  font-size: 1.05rem;
  color: var(--text-main);
  margin-bottom: 8px;
  line-height: 1.45;
}

.related-card p {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 0;
}

/* 文章末尾专属转化条 */
.article-cta-box {
  background: linear-gradient(135deg, var(--primary-light) 0%, var(--secondary-light) 100%);
  border: 1px solid rgba(79, 70, 229, 0.25);
  border-radius: var(--radius-lg);
  padding: 36px;
  text-align: center;
  margin-top: 48px;
}

.article-cta-box h3 {
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 10px;
}

.article-cta-box p {
  font-size: 0.98rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto 24px;
}

@media (max-width: 768px) {
  .article-main-card {
    padding: 26px 18px;
  }
  .article-main-title {
    font-size: 1.7rem;
  }
  .related-grid {
    grid-template-columns: 1fr;
  }
}
.subpage-container {
  max-width: 860px;
  margin: 40px auto 80px;
  padding: 0 24px;
}

.subpage-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 48px;
  box-shadow: var(--shadow-sm);
}

.subpage-header {
  margin-bottom: 36px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
}

.subpage-title {
  font-size: 2.2rem;
  font-weight: 800;
  letter-spacing: -0.8px;
  color: var(--text-main);
  margin-bottom: 10px;
}

.subpage-subtitle {
  font-size: 1rem;
  color: var(--text-muted);
}

.subpage-content {
  color: var(--text-muted);
  line-height: 1.8;
  font-size: 1rem;
}

.subpage-content h2 {
  color: var(--text-main);
  font-size: 1.4rem;
  margin: 32px 0 14px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.subpage-content h2::before {
  content: '';
  width: 4px;
  height: 20px;
  background: linear-gradient(180deg, var(--primary), var(--secondary));
  border-radius: 2px;
  display: inline-block;
}

.subpage-content p {
  margin-bottom: 16px;
}

.subpage-content ul {
  margin-left: 20px;
  margin-bottom: 20px;
}

.subpage-content li {
  margin-bottom: 8px;
}

.highlight-box {
  background: var(--primary-light);
  border: 1px solid rgba(79, 70, 229, 0.2);
  border-radius: var(--radius-md);
  padding: 20px;
  margin: 24px 0;
  color: var(--text-main);
}

.sitemap-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-top: 24px;
}

.sitemap-item {
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  padding: 20px;
  border-radius: var(--radius-md);
  transition: var(--transition-fast);
}

.sitemap-item:hover {
  border-color: var(--primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.sitemap-item h3 {
  font-size: 1.15rem;
  color: var(--text-main);
  margin-bottom: 8px;
}

.sitemap-item p {
  font-size: 0.88rem;
  color: var(--text-muted);
}

/* ==========================================================================
   推荐资讯文章专页样式 (insights-v8n3.html)
   ========================================================================== */
.article-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-top: 28px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 26px;
  transition: var(--transition-fast);
  display: flex;
  flex-direction: column;
}

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

.article-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.82rem;
  color: var(--secondary);
  font-weight: 600;
  margin-bottom: 12px;
}

.article-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 12px;
  line-height: 1.4;
}

.article-snippet {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 20px;
}

.article-link {
  margin-top: auto;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* ==========================================================================
   响应式媒体查询 (@media) - 确保手机端完美单栏呈现
   ========================================================================== */
@media (max-width: 992px) {
  .features-grid,
  .pricing-grid,
  .reviews-grid,
  .article-grid {
    grid-template-columns: 1fr;
    max-width: 520px;
    margin-left: auto;
    margin-right: auto;
  }
  
  .services-split-grid {
    grid-template-columns: 1fr;
  }
  
  .hero-title {
    font-size: 2.7rem;
  }
}

@media (max-width: 768px) {
  .nav-menu {
    display: none; /* 移动端精简头部，直奔转化 */
  }

  .hero-section {
    padding: 48px 0 35px;
  }

  .hero-title {
    font-size: 2.15rem;
    letter-spacing: -0.5px;
  }

  .hero-subtitle {
    font-size: 1rem;
    margin-bottom: 28px;
  }

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

  .hero-cta-group .btn {
    width: 100%;
    height: 52px;
    font-size: 1.05rem;
  }

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

  .metric-item {
    border-right: none;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 12px;
  }

  .metric-item:last-child {
    border-bottom: none;
    padding-bottom: 0;
  }

  .ping-strip {
    flex-direction: column;
    border-radius: var(--radius-lg);
    gap: 12px;
    padding: 14px;
  }

  .ping-regions-wrapper {
    flex-wrap: wrap;
    justify-content: center;
  }

  .section-wrapper {
    padding: 50px 0;
  }

  .section-title {
    font-size: 1.75rem;
  }

  .service-card,
  .feature-bento-card,
  .pricing-card,
  .subpage-card {
    padding: 26px 20px;
  }

  .service-chips-grid,
  .sitemap-grid {
    grid-template-columns: 1fr;
  }

  .footer-nav-list {
    flex-direction: column;
    gap: 16px;
  }
}