/* ==========================================================================
   TAGInternet - 超厚光学亚克力棱镜 UI 体系 (Thick Acrylic Prism Optical UI)
   核心设计理念：
   - 深渊暗场画布 (Abyssal dark-field canvas: #06080b)
   - 超厚高透光学亚克力切片 (Hyper-thick translucent optical acrylic slabs)
   - 棱镜色散光谱与蓝紫折射切边 (Chromatic blue-violet edge shears & caustics)
   - 物理级光学透镜焦散与 3D 浮动微交互
   ========================================================================== */

:root {
  /* ===================== 白天模式 (Pristine Optical Crystal) ===================== */
  --bg-field: #f5f7fb;
  --bg-secondary: #ebf0f8;
  --bg-acrylic: rgba(255, 255, 255, 0.75);
  --bg-acrylic-hover: rgba(255, 255, 255, 0.9);
  --bg-acrylic-heavy: rgba(255, 255, 255, 0.88);
  --bg-acrylic-nav: rgba(245, 247, 251, 0.8);
  --bg-badge: rgba(59, 130, 246, 0.08);

  /* 折射色散切边与棱镜边框 */
  --border-acrylic: rgba(255, 255, 255, 0.9);
  --border-prism: linear-gradient(135deg, rgba(56, 189, 248, 0.45) 0%, rgba(139, 92, 246, 0.35) 50%, rgba(59, 130, 246, 0.2) 100%);
  --border-prism-hover: linear-gradient(135deg, #38bdf8 0%, #8b5cf6 50%, #3b82f6 100%);
  --border-subtle: rgba(148, 163, 184, 0.22);

  /* 物理高光与焦散阴影 (Soft Caustic Shadows) */
  --specular-top: inset 0 1px 1px 0 rgba(255, 255, 255, 0.95);
  --specular-internal: inset 0 0 25px 0 rgba(255, 255, 255, 0.5);
  --caustic-shadow: 0 20px 45px -10px rgba(30, 41, 59, 0.12), 0 0 25px -5px rgba(99, 102, 241, 0.1);
  --caustic-shadow-hover: 0 30px 60px -12px rgba(30, 41, 59, 0.2), 0 0 35px 2px rgba(139, 92, 246, 0.18);

  /* 排版色彩 */
  --text-primary: #0b0f19;
  --text-secondary: #334155;
  --text-muted: #64748b;
  --text-inverse: #ffffff;

  /* 光谱色标 */
  --spectrum-blue: #2563eb;
  --spectrum-cyan: #06b6d4;
  --spectrum-violet: #7c3aed;
  --spectrum-flare: radial-gradient(circle, rgba(99, 102, 241, 0.35) 0%, rgba(6, 182, 212, 0.15) 50%, transparent 70%);
  --accent-gradient: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
  --accent-gradient-text: linear-gradient(135deg, #1d4ed8 0%, #6366f1 50%, #06b6d4 100%);

  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;

  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-smooth: 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

/* ===================== 深渊暗场模式 (Abyssal Dark-Field #06080b) ===================== */
[data-theme="dark"] {
  --bg-field: #06080b;
  --bg-secondary: #0a0e17;
  --bg-acrylic: rgba(13, 18, 30, 0.65);
  --bg-acrylic-hover: rgba(18, 26, 44, 0.82);
  --bg-acrylic-heavy: rgba(11, 15, 26, 0.78);
  --bg-acrylic-nav: rgba(6, 8, 11, 0.75);
  --bg-badge: rgba(56, 189, 248, 0.12);

  /* 棱镜色散切边 (Chromatic blue-violet edge shears) */
  --border-acrylic: rgba(255, 255, 255, 0.12);
  --border-prism: linear-gradient(135deg, rgba(56, 189, 248, 0.5) 0%, rgba(168, 85, 247, 0.45) 50%, rgba(59, 130, 246, 0.25) 100%);
  --border-prism-hover: linear-gradient(135deg, #38bdf8 0%, #a855f7 50%, #60a5fa 100%);
  --border-subtle: rgba(255, 255, 255, 0.08);

  /* 物理高光与焦散阴影 (Deep Abyssal Caustics) */
  --specular-top: inset 0 1px 1px 0 rgba(255, 255, 255, 0.35);
  --specular-internal: inset 0 0 30px 0 rgba(56, 189, 248, 0.05);
  --caustic-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.8), 0 0 35px -5px rgba(56, 189, 248, 0.15);
  --caustic-shadow-hover: 0 35px 70px -15px rgba(0, 0, 0, 0.95), 0 0 50px 4px rgba(168, 85, 247, 0.25);

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-inverse: #06080b;

  --spectrum-blue: #3b82f6;
  --spectrum-cyan: #38bdf8;
  --spectrum-violet: #a855f7;
  --spectrum-flare: radial-gradient(circle, rgba(168, 85, 247, 0.4) 0%, rgba(56, 189, 248, 0.2) 50%, transparent 70%);
  --accent-gradient: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
  --accent-gradient-text: linear-gradient(135deg, #38bdf8 0%, #a855f7 50%, #60a5fa 100%);
}

/* ==========================================================================
   全局重置与排版规范
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", Roboto, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  background-color: var(--bg-field);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  overflow-x: hidden;
  position: relative;
}

/* 深渊暗场画布透镜背景光晕 */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: 
    radial-gradient(circle at 15% 20%, rgba(56, 189, 248, 0.08) 0%, transparent 45%),
    radial-gradient(circle at 85% 65%, rgba(168, 85, 247, 0.09) 0%, transparent 50%),
    radial-gradient(circle at 50% 90%, rgba(59, 130, 246, 0.06) 0%, transparent 40%);
  pointer-events: none;
  z-index: -1;
  transition: opacity var(--transition-normal);
}

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

img, svg {
  vertical-align: middle;
}

ul, ol {
  list-style: none;
}

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

.container {
  width: 100%;
  max-width: 1220px;
  margin: 0 auto;
  padding: 0 24px;
}

.text-gradient {
  background: var(--accent-gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

/* ==========================================================================
   超厚光学亚克力基石结构 (Thick Acrylic Slab Base)
   ========================================================================== */
.acrylic-slab {
  background: var(--bg-acrylic);
  backdrop-filter: blur(28px) saturate(190%);
  -webkit-backdrop-filter: blur(28px) saturate(190%);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  box-shadow: var(--specular-top), var(--specular-internal), var(--caustic-shadow);
  position: relative;
  overflow: hidden;
  transition: transform var(--transition-smooth), box-shadow var(--transition-smooth), border-color var(--transition-smooth), background var(--transition-smooth);
  transform-style: preserve-3d;
  perspective: 1000px;
}

/* 棱镜色散切边伪元素 (Chromatic Shear Edge) */
.acrylic-slab::after {
  content: "";
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  padding: 1.5px;
  background: var(--border-prism);
  -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
  opacity: 0.75;
  transition: opacity var(--transition-normal);
}

.acrylic-slab:hover::after {
  opacity: 1;
  background: var(--border-prism-hover);
}

.acrylic-slab:hover {
  background: var(--bg-acrylic-hover);
  box-shadow: var(--specular-top), var(--specular-internal), var(--caustic-shadow-hover);
}

/* 物理焦散高光斑 (Caustic Flare Highlight) */
.acrylic-slab .caustic-glare {
  position: absolute;
  width: 250px;
  height: 250px;
  border-radius: 50%;
  background: var(--spectrum-flare);
  filter: blur(40px);
  pointer-events: none;
  opacity: 0;
  transform: translate(-50%, -50%);
  transition: opacity 0.3s ease;
  z-index: 2;
}

.acrylic-slab:hover .caustic-glare {
  opacity: 0.85;
}

/* ==========================================================================
   页眉与导航目录 (Header & Nav Directory)
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--bg-acrylic-nav);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  border-bottom: 1px solid var(--border-subtle);
  transition: background var(--transition-normal), border-color var(--transition-normal);
}

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 74px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 1.38rem;
  font-weight: 850;
  letter-spacing: -0.03em;
  color: var(--text-primary);
}

.site-brand-logo {
  height: 38px;
  width: auto;
  object-fit: contain;
  vertical-align: middle;
  filter: drop-shadow(0 2px 10px rgba(234, 58, 24, 0.2));
  transition: transform var(--transition-fast), filter var(--transition-fast);
}

.brand-logo:hover .site-brand-logo {
  transform: scale(1.05);
  filter: drop-shadow(0 4px 16px rgba(234, 58, 24, 0.45));
}

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

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

.brand-name-suffix {
  font-size: 1.32rem;
  font-weight: 850;
  letter-spacing: -0.02em;
  background: var(--accent-gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.brand-logo span.highlight {
  background: var(--accent-gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* 导航目录 (首页 + 核心优势 + 流媒体&AI + 套餐对比 + 用户评价 + 常见问题 + 推荐资讯) */
.nav-menu {
  display: flex;
  align-items: center;
  gap: 22px;
}

.nav-link {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
  position: relative;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
}

.nav-link:hover {
  color: var(--text-primary);
  background: rgba(148, 163, 184, 0.1);
}

.nav-link.active {
  color: var(--spectrum-cyan);
  background: rgba(56, 189, 248, 0.12);
}

/* 推荐资讯特别高亮徽章 */
.nav-link.nav-link-news {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--spectrum-cyan);
}

.nav-link-news .news-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #38bdf8;
  box-shadow: 0 0 8px #38bdf8;
  animation: pulse-dot 1.8s infinite;
}

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

/* 昼夜模式切换按钮 - 精致光学亚克力玻璃按钮 */
.theme-toggle-btn {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-acrylic);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: var(--specular-top), 0 2px 8px rgba(0,0,0,0.1);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.theme-toggle-btn:hover {
  background: var(--bg-acrylic-hover);
  color: var(--text-primary);
  border-color: var(--spectrum-cyan);
  transform: translateY(-2px);
  box-shadow: var(--specular-top), 0 0 16px rgba(56, 189, 248, 0.35);
}

.theme-icon-sun,
.theme-icon-moon {
  position: absolute;
  transition: transform var(--transition-smooth), opacity var(--transition-smooth);
}

[data-theme="light"] .theme-icon-moon {
  transform: rotate(90deg) scale(0);
  opacity: 0;
}
[data-theme="light"] .theme-icon-sun {
  transform: rotate(0deg) scale(1);
  opacity: 1;
}

[data-theme="dark"] .theme-icon-sun {
  transform: rotate(-90deg) scale(0);
  opacity: 0;
}
[data-theme="dark"] .theme-icon-moon {
  transform: rotate(0deg) scale(1);
  opacity: 1;
}

/* 移动端汉堡菜单 */
.mobile-toggle {
  display: none;
  width: 42px;
  height: 42px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  background: var(--bg-acrylic);
  border: 1px solid var(--border-subtle);
}

/* ==========================================================================
   按钮组件 (CTA 规范与光学焦散点击微交互)
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius-full);
  font-size: 0.95rem;
  font-weight: 600;
  line-height: 1.2;
  transition: all var(--transition-normal);
  white-space: nowrap;
  user-select: none;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: var(--accent-gradient);
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.25);
  box-shadow: 0 6px 20px rgba(56, 189, 248, 0.35), inset 0 1px 1px rgba(255, 255, 255, 0.5);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(168, 85, 247, 0.45), 0 0 20px rgba(56, 189, 248, 0.3), inset 0 1px 1px rgba(255, 255, 255, 0.7);
  color: #ffffff;
}

.btn-secondary {
  background: var(--bg-acrylic);
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
  box-shadow: var(--specular-top), 0 4px 12px rgba(0, 0, 0, 0.08);
}

.btn-secondary:hover {
  background: var(--bg-acrylic-hover);
  border-color: var(--spectrum-cyan);
  color: var(--spectrum-cyan);
  transform: translateY(-2px);
  box-shadow: var(--specular-top), 0 0 20px rgba(56, 189, 248, 0.25);
}

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

.btn-block {
  width: 100%;
}

/* 按钮点击聚焦散爆闪 (Optical Caustic Flare Flash) */
.optical-flare-pulse {
  animation: flare-pop 0.55s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes flare-pop {
  0% { transform: scale(0.96); box-shadow: 0 0 0 0 rgba(56, 189, 248, 0.8), inset 0 0 30px rgba(255, 255, 255, 0.8); }
  60% { transform: scale(1.02); box-shadow: 0 0 40px 10px rgba(168, 85, 247, 0.6), inset 0 0 50px rgba(255, 255, 255, 0.9); }
  100% { transform: scale(1); box-shadow: 0 6px 20px rgba(56, 189, 248, 0.35); }
}

/* ==========================================================================
   主视觉区 (Hero Section) - 必须包含品牌名与完整简介
   ========================================================================== */
.hero-section {
  position: relative;
  padding: 95px 0 80px;
  text-align: center;
  overflow: hidden;
}

.hero-prism-spectrum {
  position: absolute;
  top: 10%;
  left: 50%;
  transform: translateX(-50%);
  width: 850px;
  height: 480px;
  background: 
    radial-gradient(circle at 30% 30%, rgba(56, 189, 248, 0.22) 0%, transparent 55%),
    radial-gradient(circle at 70% 40%, rgba(168, 85, 247, 0.2) 0%, transparent 60%),
    radial-gradient(circle at 50% 80%, rgba(59, 130, 246, 0.15) 0%, transparent 50%);
  filter: blur(60px);
  pointer-events: none;
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 1140px;
  margin: 0 auto;
}

.hero-badge-slab {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 20px;
  border-radius: var(--radius-full);
  background: var(--bg-acrylic);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-subtle);
  box-shadow: var(--specular-top), 0 4px 15px rgba(0, 0, 0, 0.08);
  color: var(--spectrum-cyan);
  font-size: 0.88rem;
  font-weight: 700;
  margin-bottom: 28px;
}

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

@keyframes pulse-dot {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
  70% { transform: scale(1.05); box-shadow: 0 0 0 10px rgba(16, 185, 129, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

/* 大标题必须包含当前品牌名 TAGInternet */
.hero-headline {
  font-size: 3.1rem;
  font-weight: 850;
  letter-spacing: -0.035em;
  line-height: 1.2;
  margin-bottom: 24px;
}

.hero-headline .hero-title-main {
  display: block;
  margin-bottom: 12px;
}

.hero-headline .hero-title-sub {
  display: block;
  font-size: clamp(1.2rem, 2.35vw, 2.05rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  white-space: nowrap;
}

.hero-headline .brand-focus {
  background: var(--accent-gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
  padding: 0 4px;
}

/* 主视觉区简介 */
.hero-subheadline {
  font-size: 1.25rem;
  color: var(--text-secondary);
  line-height: 1.68;
  max-width: 740px;
  margin: 0 auto 40px;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 18px;
  margin-bottom: 60px;
  flex-wrap: wrap;
}

/* 光学厚切板核心指标栏 (Stats Slab) */
.hero-stats-slab {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  padding: 30px 36px;
  margin-top: 10px;
}

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

.stat-value {
  font-size: 1.95rem;
  font-weight: 850;
  line-height: 1.1;
  margin-bottom: 8px;
}

.stat-label {
  font-size: 0.86rem;
  color: var(--text-muted);
  font-weight: 600;
}

/* ==========================================================================
   通用 Section 规范
   ========================================================================== */
.section {
  padding: 90px 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 60px;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.82rem;
  font-weight: 750;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--spectrum-cyan);
  margin-bottom: 12px;
  padding: 4px 12px;
  border-radius: var(--radius-full);
  background: var(--bg-badge);
  border: 1px solid var(--border-subtle);
}

.section-title {
  font-size: 2.35rem;
  font-weight: 850;
  letter-spacing: -0.025em;
  line-height: 1.25;
  margin-bottom: 16px;
}

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

/* ==========================================================================
   产品核心优势介绍 (3个厚切光学亚克力图文卡片)
   ========================================================================== */
.core-features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.feature-card {
  padding: 40px 32px;
  display: flex;
  flex-direction: column;
}

.feature-card:hover {
  transform: translateY(-8px);
}

.feature-icon-prism {
  width: 62px;
  height: 62px;
  border-radius: 16px;
  background: var(--bg-badge);
  border: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--spectrum-cyan);
  margin-bottom: 26px;
  box-shadow: inset 0 1px 1px rgba(255,255,255,0.4), 0 4px 16px rgba(56, 189, 248, 0.2);
  transition: transform var(--transition-fast), color var(--transition-fast);
}

.feature-card:hover .feature-icon-prism {
  transform: scale(1.1);
  color: var(--spectrum-violet);
}

.feature-title {
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 14px;
  color: var(--text-primary);
}

.feature-desc {
  font-size: 0.96rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 24px;
  flex-grow: 1;
}

.feature-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.feature-pill {
  font-size: 0.78rem;
  font-weight: 600;
  padding: 4px 12px;
  background: rgba(148, 163, 184, 0.12);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  color: var(--text-muted);
}

/* ==========================================================================
   流媒体图卡 & AI 支持图卡 (Special Optical Showcase)
   ========================================================================== */
.showcase-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.showcase-card {
  padding: 44px 38px;
}

.showcase-card:hover {
  transform: translateY(-6px);
}

.showcase-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 22px;
}

.showcase-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.76rem;
  font-weight: 750;
  padding: 6px 14px;
  border-radius: var(--radius-full);
}

.card-streaming .showcase-badge {
  background: rgba(239, 68, 68, 0.12);
  color: #ef4444;
  border: 1px solid rgba(239, 68, 68, 0.3);
}

.card-ai .showcase-badge {
  background: rgba(168, 85, 247, 0.15);
  color: #c084fc;
  border: 1px solid rgba(168, 85, 247, 0.3);
}

.showcase-card-title {
  font-size: 1.75rem;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 16px;
}

.showcase-card-desc {
  font-size: 0.98rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 30px;
}

.media-badges-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-bottom: 30px;
}

.media-badge-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 14px;
  border-radius: var(--radius-md);
  background: rgba(148, 163, 184, 0.08);
  border: 1px solid var(--border-subtle);
  font-size: 0.86rem;
  font-weight: 600;
  color: var(--text-primary);
  transition: all var(--transition-fast);
}

.media-badge-item:hover {
  background: rgba(56, 189, 248, 0.15);
  border-color: var(--spectrum-cyan);
  transform: translateY(-2px);
}

.showcase-features-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.showcase-feature-row {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.92rem;
  color: var(--text-secondary);
}

.showcase-feature-row svg {
  color: #10b981;
  flex-shrink: 0;
}

/* ==========================================================================
   套餐价格对比表 (参考网上真实主流专线机场价格)
   ========================================================================== */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
  align-items: stretch;
  padding-top: 18px;
}

.pricing-card {
  padding: 42px 32px;
  display: flex;
  flex-direction: column;
}

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

/* 进阶畅享款 - 高亮光学焦散与彩虹边缘 */
.pricing-card.featured {
  overflow: visible;
  position: relative;
  border: 1px solid var(--spectrum-cyan);
  box-shadow: var(--specular-top), 0 0 40px rgba(56, 189, 248, 0.25), var(--caustic-shadow-hover);
}

.pricing-card.featured::after {
  opacity: 1;
  background: var(--border-prism-hover);
}

.featured-ribbon {
  position: absolute;
  top: -15px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent-gradient);
  color: #ffffff;
  font-size: 0.8rem;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: 0.05em;
  padding: 6px 20px;
  border-radius: var(--radius-full);
  box-shadow: 0 4px 16px rgba(168, 85, 247, 0.5), inset 0 1px 1px rgba(255,255,255,0.6);
  z-index: 10;
  white-space: nowrap;
}

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

.pricing-tier-name {
  font-size: 1.35rem;
  font-weight: 850;
  margin-bottom: 8px;
}

.pricing-tier-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.5;
}

.pricing-price-box {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 26px;
  padding-bottom: 26px;
  border-bottom: 1px solid var(--border-subtle);
}

.price-currency {
  font-size: 1.35rem;
  font-weight: 750;
  color: var(--text-primary);
}

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

.price-period {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.pricing-features {
  display: flex;
  flex-direction: column;
  gap: 15px;
  margin-bottom: 34px;
  flex-grow: 1;
}

.pricing-feature-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.94rem;
  color: var(--text-secondary);
}

.pricing-feature-item svg {
  flex-shrink: 0;
  color: #10b981;
  margin-top: 2px;
}

.pricing-feature-item.disabled {
  color: var(--text-muted);
  opacity: 0.5;
}

.pricing-feature-item.disabled svg {
  color: var(--text-muted);
}

/* ==========================================================================
   用户真实评价 (Testimonials)
   ========================================================================== */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.testimonial-card {
  padding: 34px 30px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.testimonial-card:hover {
  transform: translateY(-5px);
}

.testimonial-stars {
  display: flex;
  gap: 4px;
  color: #f59e0b;
  margin-bottom: 18px;
}

.testimonial-comment {
  font-size: 0.96rem;
  line-height: 1.7;
  color: var(--text-secondary);
  margin-bottom: 26px;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 14px;
  padding-top: 20px;
  border-top: 1px solid var(--border-subtle);
}

.author-avatar {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: var(--accent-gradient);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 750;
  font-size: 1.05rem;
  box-shadow: 0 4px 12px rgba(56, 189, 248, 0.3);
}

.author-info h4 {
  font-size: 0.98rem;
  font-weight: 750;
  color: var(--text-primary);
}

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

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

.faq-item {
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all var(--transition-fast);
}

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

.faq-question {
  width: 100%;
  padding: 22px 28px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  text-align: left;
  font-size: 1.08rem;
  font-weight: 750;
  color: var(--text-primary);
  background: none;
  cursor: pointer;
  transition: color var(--transition-fast);
}

.faq-icon-chevron {
  transition: transform var(--transition-normal);
  color: var(--text-muted);
  flex-shrink: 0;
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-smooth), padding var(--transition-smooth);
  padding: 0 28px;
  font-size: 0.98rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  max-height: 280px;
  padding: 0 28px 24px 28px;
}

/* ==========================================================================
   底部行动号召 (Bottom CTA Strip)
   ========================================================================== */
.bottom-cta-banner {
  margin: 70px 0 0;
  padding: 65px 44px;
  background: var(--accent-gradient);
  border-radius: var(--radius-lg);
  color: #ffffff;
  text-align: center;
  box-shadow: 0 20px 50px rgba(56, 189, 248, 0.35), inset 0 1px 1px rgba(255, 255, 255, 0.4);
  position: relative;
  overflow: hidden;
}

.bottom-cta-banner h2 {
  font-size: 2.3rem;
  font-weight: 850;
  margin-bottom: 16px;
}

.bottom-cta-banner p {
  font-size: 1.12rem;
  opacity: 0.92;
  max-width: 640px;
  margin: 0 auto 34px;
}

.btn-white {
  background: #ffffff;
  color: #1d4ed8;
  font-weight: 750;
  box-shadow: 0 4px 18px rgba(0, 0, 0, 0.2);
}

.btn-white:hover {
  background: #f8fafc;
  transform: translateY(-2px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
  color: #2563eb;
}

/* ==========================================================================
   页脚规范 (严格仅保留四个标题，在新页面打开)
   1. 网站地图
   2. 关于我们
   3. 服务条款
   4. 隐私政策
   ========================================================================== */
.site-footer {
  margin-top: auto;
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-subtle);
  padding: 48px 0 36px;
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 40px;
  margin-bottom: 26px;
  flex-wrap: wrap;
}

.footer-link {
  font-size: 1.02rem;
  font-weight: 650;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.footer-link:hover {
  color: var(--spectrum-cyan);
  transform: translateY(-1px);
}

.footer-divider {
  width: 1px;
  height: 14px;
  background: var(--border-subtle);
}

.footer-copy {
  text-align: center;
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.footer-copy a {
  color: var(--text-muted);
  text-decoration: underline;
  text-underline-offset: 4px;
}

.footer-copy a:hover {
  color: var(--spectrum-cyan);
}

/* ==========================================================================
   独立子页面通用样式 (about, terms, privacy, sitemap, news)
   ========================================================================== */
.subpage-hero {
  padding: 75px 0 45px;
  text-align: center;
  border-bottom: 1px solid var(--border-subtle);
  background: var(--bg-secondary);
}

.subpage-hero h1 {
  font-size: 2.6rem;
  font-weight: 850;
  margin-bottom: 14px;
  letter-spacing: -0.025em;
}

.subpage-hero p {
  font-size: 1.12rem;
  color: var(--text-secondary);
  max-width: 680px;
  margin: 0 auto;
}

.subpage-content {
  padding: 65px 0 95px;
  max-width: 900px;
  margin: 0 auto;
}

.prose-section {
  padding: 44px 38px;
  margin-bottom: 32px;
}

.prose-section h2 {
  font-size: 1.55rem;
  font-weight: 800;
  margin-bottom: 18px;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 12px;
}

.prose-section p {
  font-size: 1.02rem;
  color: var(--text-secondary);
  line-height: 1.78;
  margin-bottom: 18px;
}

.prose-section ul {
  margin: 14px 0 22px 24px;
  list-style: disc;
}

.prose-section li {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.72;
  margin-bottom: 10px;
}

.callout-box {
  padding: 22px 26px;
  border-radius: var(--radius-md);
  margin: 22px 0;
  border-left: 4px solid var(--spectrum-cyan);
  background: var(--bg-badge);
  font-size: 0.98rem;
  line-height: 1.7;
  color: var(--text-primary);
}

.callout-box.warning {
  border-left-color: #ef4444;
  background: rgba(239, 68, 68, 0.08);
}

.callout-box.success {
  border-left-color: #10b981;
  background: rgba(16, 185, 129, 0.08);
}

/* 资讯中心文章列表卡片 (Insights / News) */
.news-grid {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.news-card {
  padding: 38px 34px;
  display: flex;
  flex-direction: column;
}

.news-meta {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 14px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.news-tag {
  color: var(--spectrum-cyan);
  font-weight: 700;
  background: var(--bg-badge);
  padding: 3px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
}

.news-title {
  font-size: 1.45rem;
  font-weight: 800;
  margin-bottom: 14px;
  color: var(--text-primary);
  line-height: 1.35;
}

.news-excerpt {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.75;
  margin-bottom: 22px;
}

.news-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 18px;
  border-top: 1px solid var(--border-subtle);
}

/* ==========================================================================
   深度科普长篇 SEO 文章排版规范 (Article Layout & Typography)
   ========================================================================== */
.breadcrumb-nav {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 24px;
  flex-wrap: wrap;
}

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

.breadcrumb-nav a:hover {
  color: var(--spectrum-cyan);
}

.breadcrumb-separator {
  color: var(--border-subtle);
}

.article-header {
  margin-bottom: 36px;
  text-align: left;
}

.article-headline {
  font-size: 2.4rem;
  font-weight: 850;
  line-height: 1.25;
  letter-spacing: -0.025em;
  color: var(--text-primary);
  margin: 16px 0 20px;
}

.article-meta-bar {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.9rem;
  color: var(--text-muted);
  flex-wrap: wrap;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-subtle);
}

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

/* 目录面板 (Table of Contents) */
.article-toc {
  margin: 32px 0 40px;
  padding: 26px 30px;
  border-left: 4px solid var(--spectrum-cyan);
}

.article-toc-title {
  font-size: 1.15rem;
  font-weight: 800;
  margin-bottom: 16px;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 10px;
}

.article-toc-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-left: 0 !important;
  list-style: none !important;
}

.article-toc-list a {
  color: var(--text-secondary);
  font-size: 0.96rem;
  font-weight: 550;
  display: inline-block;
  transition: all var(--transition-fast);
}

.article-toc-list a:hover {
  color: var(--spectrum-cyan);
  transform: translateX(4px);
}

.article-toc-list .toc-sub {
  margin-left: 20px;
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* 文章正文 (Article Content Body) */
.article-body {
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--text-secondary);
}

.article-body h2 {
  font-size: 1.7rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin: 44px 0 20px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  gap: 10px;
}

.article-body h3 {
  font-size: 1.3rem;
  font-weight: 750;
  color: var(--text-primary);
  margin: 30px 0 14px;
}

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

.article-body ul, .article-body ol {
  margin: 16px 0 24px 28px;
}

.article-body li {
  margin-bottom: 10px;
  line-height: 1.75;
}

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

/* 站内核心高亮链接 (SEO Internal Links) */
.article-internal-link {
  color: var(--spectrum-cyan);
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: 4px;
  transition: all var(--transition-fast);
}

.article-internal-link:hover {
  color: var(--spectrum-violet);
  background: rgba(56, 189, 248, 0.12);
  border-radius: 4px;
  padding: 0 4px;
}

/* 对比表格 (Data & Spec Comparison Table) */
.table-responsive {
  width: 100%;
  overflow-x: auto;
  margin: 28px 0;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
}

.spec-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.94rem;
  text-align: left;
}

.spec-table th {
  background: var(--bg-badge);
  color: var(--text-primary);
  font-weight: 750;
  padding: 14px 18px;
  border-bottom: 1px solid var(--border-subtle);
  white-space: nowrap;
}

.spec-table td {
  padding: 14px 18px;
  border-bottom: 1px solid var(--border-subtle);
  color: var(--text-secondary);
}

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

.spec-table tr:hover td {
  background: rgba(148, 163, 184, 0.05);
}

/* 代码与配置块 */
.code-block {
  background: #090d16;
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 18px 22px;
  margin: 22px 0;
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.9rem;
  color: #38bdf8;
  overflow-x: auto;
  line-height: 1.6;
}

/* 相关阅读网格 (Related Reading Grid) */
.related-reading-box {
  margin-top: 55px;
  padding-top: 35px;
  border-top: 1px solid var(--border-subtle);
}

.related-reading-title {
  font-size: 1.35rem;
  font-weight: 800;
  margin-bottom: 22px;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 10px;
}

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

.related-card {
  padding: 22px 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.related-card h4 {
  font-size: 1.05rem;
  font-weight: 750;
  color: var(--text-primary);
  margin-bottom: 10px;
  line-height: 1.4;
}

.related-card:hover h4 {
  color: var(--spectrum-cyan);
}

.related-card p {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.55;
  margin-bottom: 14px;
}

/* 网站地图样式 */
.sitemap-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.sitemap-card {
  padding: 34px 28px;
}

.sitemap-card h3 {
  font-size: 1.3rem;
  font-weight: 800;
  margin-bottom: 20px;
  color: var(--text-primary);
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-subtle);
}

.sitemap-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.sitemap-list a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.98rem;
  color: var(--text-secondary);
  padding: 8px 0;
  border-bottom: 1px dashed var(--border-subtle);
}

.sitemap-list a:hover {
  color: var(--spectrum-cyan);
  padding-left: 8px;
}

/* ==========================================================================
   响应式媒体查询 (Mobile & Tablet)
   ========================================================================== */
@media (max-width: 992px) {
  .core-features-grid,
  .pricing-grid,
  .testimonials-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

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

  .hero-headline .hero-title-sub {
    font-size: clamp(1.1rem, 2.3vw, 1.75rem);
    white-space: nowrap;
  }
}

@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    top: 74px;
    left: 0;
    right: 0;
    background: var(--bg-acrylic-heavy);
    backdrop-filter: blur(28px);
    -webkit-backdrop-filter: blur(28px);
    border-bottom: 1px solid var(--border-subtle);
    padding: 24px;
    flex-direction: column;
    align-items: flex-start;
    gap: 14px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.4);
    display: none;
  }

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

  .mobile-toggle {
    display: flex;
  }

  .nav-link {
    font-size: 1.05rem;
    width: 100%;
    padding: 10px 14px;
  }

  .hero-section {
    padding: 55px 0 45px;
  }

  .hero-headline {
    font-size: 2.05rem;
  }

  .hero-headline .hero-title-sub {
    font-size: clamp(0.95rem, 2.8vw, 1.35rem);
    white-space: nowrap;
  }

  .hero-subheadline {
    font-size: 1.05rem;
    margin-bottom: 30px;
  }

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

  .hero-cta-group .btn {
    width: 100%;
    min-height: 48px;
  }

  .hero-stats-slab {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    padding: 20px 16px;
  }

  .stat-value {
    font-size: 1.55rem;
  }

  .core-features-grid,
  .pricing-grid,
  .testimonials-grid,
  .sitemap-grid,
  .related-grid {
    grid-template-columns: 1fr;
    gap: 22px;
  }

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

  .section {
    padding: 60px 0;
  }

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

  .feature-card,
  .showcase-card,
  .pricing-card,
  .prose-section {
    padding: 30px 22px;
  }

  .bottom-cta-banner {
    padding: 44px 22px;
  }

  .bottom-cta-banner h2 {
    font-size: 1.75rem;
  }

  .footer-nav {
    flex-direction: column;
    gap: 18px;
  }

  .footer-divider {
    display: none;
  }

  .btn {
    min-height: 48px; /* 适合手机手指触碰体验 */
  }
}

@media (max-width: 480px) {
  .hero-headline {
    font-size: 1.8rem;
  }
  .hero-headline .hero-title-sub {
    font-size: 1.1rem;
    white-space: normal;
    line-height: 1.4;
  }
}