/* ==========================================================================
   耶耶云 (YeYe Cloud) - Scandinavian Coastal-Breeze Design System
   Fluid Organic Glassmorphism & High-Precision Interaction Engine
   ========================================================================== */

/* 1. Design Tokens & Color Palette */
:root {
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;

  /* Coastal-Breeze Palette (Light Mode - Default) */
  --cobalt-primary: #1D4ED8;
  --cobalt-hover: #1e40af;
  --cobalt-light: #3b82f6;
  --polar-ice: #F0F7FF;
  --polar-ice-alt: #e0f0fe;
  
  --bg-page: #f8fbff;
  --bg-surface: #ffffff;
  --bg-subtle: #f0f7ff;
  --bg-glass: rgba(255, 255, 255, 0.72);
  --bg-glass-card: rgba(255, 255, 255, 0.75);
  --bg-glass-active: rgba(255, 255, 255, 0.92);
  --bg-nav: rgba(248, 251, 255, 0.85);

  --text-main: #0b192c;
  --text-muted: #475569;
  --text-faint: #94a3b8;
  --text-tag: #1d4ed8;

  /* Specular 1px White Glass Borders */
  --border-specular: rgba(255, 255, 255, 0.9);
  --border-light: rgba(29, 78, 216, 0.1);
  --border-card: rgba(219, 234, 254, 0.8);
  --border-card-hover: rgba(29, 78, 216, 0.45);

  --accent-gradient: linear-gradient(135deg, #1D4ED8 0%, #2563EB 50%, #0284c7 100%);
  --accent-gradient-wave: linear-gradient(135deg, rgba(29, 78, 216, 0.08) 0%, rgba(56, 189, 248, 0.08) 100%);
  --accent-glow: rgba(29, 78, 216, 0.18);
  --badge-glow: rgba(29, 78, 216, 0.25);

  --shadow-ambient: 0 8px 32px 0 rgba(29, 78, 216, 0.08);
  --shadow-glass: 0 16px 36px -4px rgba(29, 78, 216, 0.1), 0 0 0 1px rgba(255, 255, 255, 0.85) inset;
  --shadow-lift: 0 24px 48px -12px rgba(29, 78, 216, 0.18), 0 0 0 1px rgba(255, 255, 255, 1) inset;

  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 22px;
  --radius-xl: 30px;
  --radius-full: 9999px;

  --transition-fast: 0.2s cubic-bezier(0.2, 0, 0, 1);
  --transition-normal: 0.35s cubic-bezier(0.25, 1, 0.5, 1);
  --transition-spring: 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
  --transition-slow: 0.5s ease;
}

/* Dark Mode Tokens */
[data-theme="dark"] {
  --cobalt-primary: #3b82f6;
  --cobalt-hover: #60a5fa;
  --cobalt-light: #93c5fd;
  --polar-ice: #0f172a;
  --polar-ice-alt: #1e293b;

  --bg-page: #070b14;
  --bg-surface: #0f172a;
  --bg-subtle: #0d1526;
  --bg-glass: rgba(15, 23, 42, 0.75);
  --bg-glass-card: rgba(17, 27, 49, 0.72);
  --bg-glass-active: rgba(24, 38, 68, 0.9);
  --bg-nav: rgba(7, 11, 20, 0.85);

  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-faint: #64748b;
  --text-tag: #60a5fa;

  --border-specular: rgba(255, 255, 255, 0.15);
  --border-light: rgba(59, 130, 246, 0.18);
  --border-card: rgba(30, 48, 80, 0.8);
  --border-card-hover: rgba(59, 130, 246, 0.6);

  --accent-gradient: linear-gradient(135deg, #2563eb 0%, #38bdf8 100%);
  --accent-gradient-wave: linear-gradient(135deg, rgba(37, 99, 235, 0.15) 0%, rgba(56, 189, 248, 0.1) 100%);
  --accent-glow: rgba(59, 130, 246, 0.3);
  --badge-glow: rgba(59, 130, 246, 0.4);

  --shadow-ambient: 0 8px 32px 0 rgba(0, 0, 0, 0.5);
  --shadow-glass: 0 16px 36px -4px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(255, 255, 255, 0.12) inset;
  --shadow-lift: 0 24px 48px -12px rgba(59, 130, 246, 0.3), 0 0 0 1px rgba(255, 255, 255, 0.2) inset;
}

/* 2. Reset & Layout Setup */
*, *::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-page);
  color: var(--text-main);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  transition: background-color var(--transition-slow), color var(--transition-slow);
  overflow-x: hidden;
  position: relative;
}

/* 锚点平滑跳转预留顶部导航偏移 */
section[id], div[id] {
  scroll-margin-top: 86px;
}

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

.container {
  width: 100%;
  max-width: 1220px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 2;
}

/* 3. Interactive Physics Fluid Canvas Background */
#fluid-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 0;
  opacity: 0.75;
  transition: opacity 0.5s ease;
}

[data-theme="dark"] #fluid-canvas {
  opacity: 0.45;
}

/* 4. 头部导航 (Navbar) */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-nav);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-light);
  box-shadow: 0 4px 20px -2px rgba(29, 78, 216, 0.04);
  transition: background-color var(--transition-slow), border-color var(--transition-slow);
}

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

.nav-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-main);
  text-decoration: none;
}

.brand-icon-wrap {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-md);
  background: var(--accent-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  box-shadow: 0 6px 16px var(--badge-glow);
  position: relative;
  overflow: hidden;
}

.brand-icon-wrap::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  border-radius: inherit;
  box-shadow: inset 0 1px 1px rgba(255, 255, 255, 0.6);
}

.brand-name {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  font-weight: 900;
  letter-spacing: -0.02em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-link {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-muted);
  position: relative;
  padding: 6px 4px;
  transition: color var(--transition-fast);
}

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

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%) scaleX(0);
  width: 18px;
  height: 2px;
  background: var(--cobalt-primary);
  border-radius: var(--radius-full);
  transition: transform var(--transition-normal);
}

.nav-link:hover::after,
.nav-link.active::after {
  transform: translateX(-50%) scaleX(1);
}

/* 推荐资讯入口高亮小角标 */
.nav-link-badge {
  background: var(--polar-ice);
  color: var(--cobalt-primary);
  font-size: 0.72rem;
  padding: 2px 7px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-light);
  font-weight: 700;
  margin-left: 4px;
}

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

/* 昼夜模式切换按钮（极致剔透、北欧微质感） */
.theme-toggle-btn {
  background: var(--bg-glass);
  border: 1px solid var(--border-specular);
  border-radius: var(--radius-full);
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-muted);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: all var(--transition-normal);
  padding: 0;
  outline: none;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

.theme-toggle-btn:hover {
  color: var(--cobalt-primary);
  border-color: var(--cobalt-light);
  transform: translateY(-2px);
  box-shadow: var(--shadow-ambient);
}

.theme-icon-sun { display: none; }
.theme-icon-moon { display: block; }

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

/* 5. 按钮系统 (CTA Buttons) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 24px;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
  cursor: pointer;
  border: none;
  text-align: center;
  white-space: nowrap;
}

.btn-primary {
  background: var(--accent-gradient);
  color: #ffffff !important;
  box-shadow: 0 4px 16px var(--badge-glow), inset 0 1px 1px rgba(255, 255, 255, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px var(--accent-glow), inset 0 1px 1px rgba(255, 255, 255, 0.6);
  filter: brightness(1.05);
}

.btn-outline {
  background: var(--bg-glass);
  color: var(--text-main);
  border: 1px solid var(--border-card);
  backdrop-filter: blur(8px);
}

.btn-outline:hover {
  border-color: var(--cobalt-primary);
  color: var(--cobalt-primary);
  background: var(--bg-surface);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 14px 34px;
  font-size: 1.05rem;
  border-radius: var(--radius-lg);
}

.btn-block {
  width: 100%;
}

/* 6. 主视觉 Hero 区域 (Scandinavian Editorial Layout) */
.hero-section {
  position: relative;
  padding: 70px 0 60px;
  overflow: hidden;
}

.hero-content {
  text-align: center;
  max-width: 880px;
  margin: 0 auto 50px;
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 18px;
  background: var(--bg-glass);
  border: 1px solid var(--border-specular);
  border-radius: var(--radius-full);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--cobalt-primary);
  margin-bottom: 26px;
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow-ambient);
}

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

@keyframes pulse-live {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(0.8); opacity: 0.6; }
}

/* 大标题必须明确包含当前品牌名‘耶耶云’ */
.hero-title {
  font-size: clamp(2.3rem, 5.2vw, 3.9rem);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -0.035em;
  margin-bottom: 22px;
  color: var(--text-main);
}

.hero-subtitle {
  font-size: clamp(1.05rem, 2vw, 1.25rem);
  color: var(--text-muted);
  line-height: 1.75;
  margin-bottom: 36px;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

/* Floating Acrylic Glass Slabs - 浮动亚克力玻璃监控看板 */
.acrylic-stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 1040px;
  margin: 0 auto;
}

.acrylic-slab {
  background: var(--bg-glass-card);
  border: 1px solid var(--border-specular);
  border-radius: var(--radius-xl);
  padding: 24px 20px;
  box-shadow: var(--shadow-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.acrylic-slab:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lift);
  border-color: var(--border-card-hover);
}

.slab-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.slab-title {
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-faint);
}

.slab-badge {
  font-size: 0.72rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  background: rgba(16, 185, 129, 0.12);
  color: #10b981;
}

.slab-value {
  font-size: 2rem;
  font-weight: 900;
  color: var(--text-main);
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 6px;
}

.slab-desc {
  font-size: 0.84rem;
  color: var(--text-muted);
}

/* Live Traffic Bar */
.traffic-progress-bar {
  width: 100%;
  height: 4px;
  background: var(--border-card);
  border-radius: var(--radius-full);
  margin-top: 10px;
  overflow: hidden;
}

.traffic-progress-val {
  height: 100%;
  background: var(--accent-gradient);
  border-radius: var(--radius-full);
}

/* 7. Fluid Wave Contour Divider */
.wave-divider {
  width: 100%;
  overflow: hidden;
  line-height: 0;
  transform: translateZ(0);
}

.wave-divider svg {
  position: relative;
  display: block;
  width: calc(100% + 1.3px);
  height: 60px;
}

.wave-divider .shape-fill {
  fill: var(--bg-subtle);
  transition: fill var(--transition-slow);
}

.wave-divider.invert {
  transform: rotate(180deg);
}

/* 8. 公共区块标题 */
.section-space {
  padding: 85px 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 55px;
}

.section-tag {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--cobalt-primary);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(1.85rem, 3.6vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.025em;
  margin-bottom: 14px;
  color: var(--text-main);
}

.section-desc {
  font-size: 1.02rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* 9. 3D Spatial Tilt Feature Cards (3个图文卡片) */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  perspective: 1200px;
}

.feature-card {
  background: var(--bg-glass-card);
  border: 1px solid var(--border-specular);
  border-radius: var(--radius-xl);
  padding: 38px 30px;
  box-shadow: var(--shadow-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  transition: transform 0.25s ease-out, box-shadow 0.25s ease-out, border-color 0.25s ease-out;
  display: flex;
  flex-direction: column;
  position: relative;
  transform-style: preserve-3d;
  will-change: transform;
}

.feature-card:hover {
  border-color: var(--border-card-hover);
  box-shadow: var(--shadow-lift);
}

.feature-icon-box {
  width: 62px;
  height: 62px;
  border-radius: var(--radius-lg);
  background: var(--polar-ice);
  border: 1px solid var(--border-specular);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--cobalt-primary);
  margin-bottom: 24px;
  transition: all var(--transition-normal);
}

.feature-card:hover .feature-icon-box {
  background: var(--accent-gradient);
  color: #ffffff;
  transform: translateZ(18px);
}

.feature-title {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-main);
}

.feature-text {
  font-size: 0.96rem;
  color: var(--text-muted);
  line-height: 1.7;
  flex-grow: 1;
}

.feature-pill-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 24px;
}

.feature-pill {
  font-size: 0.78rem;
  font-weight: 600;
  padding: 5px 12px;
  border-radius: var(--radius-full);
  background: var(--polar-ice);
  color: var(--cobalt-primary);
  border: 1px solid var(--border-light);
}

/* 10. 流媒体与 AI 支持图卡展示区 */
.media-ai-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
  perspective: 1200px;
}

.showcase-card {
  background: var(--bg-glass-card);
  border: 1px solid var(--border-specular);
  border-radius: var(--radius-xl);
  padding: 42px;
  box-shadow: var(--shadow-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  position: relative;
  overflow: hidden;
  transition: transform 0.25s ease-out, box-shadow 0.25s ease-out;
  display: flex;
  flex-direction: column;
  transform-style: preserve-3d;
  will-change: transform;
}

.showcase-card:hover {
  box-shadow: var(--shadow-lift);
  border-color: var(--border-card-hover);
}

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

.showcase-icon {
  width: 54px;
  height: 54px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  flex-shrink: 0;
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.15);
}

.icon-streaming {
  background: linear-gradient(135deg, #e50914 0%, #ff5e62 100%);
}

.icon-ai {
  background: linear-gradient(135deg, #059669 0%, #2563eb 100%);
}

.showcase-title {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-main);
}

.showcase-desc {
  font-size: 1rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 26px;
}

.platform-badges-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-bottom: 28px;
}

.platform-badge {
  background: var(--polar-ice);
  border: 1px solid var(--border-specular);
  border-radius: var(--radius-md);
  padding: 14px 10px;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 8px;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-main);
  transition: all var(--transition-fast);
}

.platform-badge:hover {
  background: var(--bg-surface);
  border-color: var(--cobalt-primary);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(29, 78, 216, 0.08);
}

.platform-badge svg {
  width: 26px;
  height: 26px;
}

.showcase-highlights {
  list-style: none;
  margin-top: auto;
  border-top: 1px solid var(--border-light);
  padding-top: 20px;
}

.showcase-highlights li {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-bottom: 10px;
}

.showcase-highlights li svg {
  color: #10b981;
  flex-shrink: 0;
}

/* 11. Server Node Selector with Fluid Sliding Tabs (节点选择器) */
.node-selector-wrap {
  background: var(--bg-glass-card);
  border: 1px solid var(--border-specular);
  border-radius: var(--radius-xl);
  padding: 36px;
  box-shadow: var(--shadow-glass);
  backdrop-filter: blur(16px);
  margin: 0 auto;
}

/* Fluid Sliding Tabs Nav */
.tabs-nav-container {
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  background: var(--polar-ice);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-full);
  padding: 6px;
  max-width: 640px;
  margin: 0 auto 36px;
}

/* Sliding active pill indicator that stretches */
.tab-active-pill {
  position: absolute;
  top: 6px;
  bottom: 6px;
  left: 6px;
  background: var(--accent-gradient);
  border-radius: var(--radius-full);
  box-shadow: 0 4px 14px var(--badge-glow);
  pointer-events: none;
  transition: transform var(--transition-spring), width var(--transition-spring);
  will-change: transform, width;
}

.tab-btn {
  flex: 1;
  position: relative;
  z-index: 2;
  background: none;
  border: none;
  padding: 10px 18px;
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--text-muted);
  cursor: pointer;
  border-radius: var(--radius-full);
  transition: color var(--transition-fast);
  outline: none;
  text-align: center;
}

.tab-btn.active {
  color: #ffffff;
}

/* Nodes Grid for the Active Tab */
.nodes-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.node-item-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 22px;
  transition: all var(--transition-fast);
  display: flex;
  flex-direction: column;
}

.node-item-card:hover {
  border-color: var(--cobalt-primary);
  transform: translateY(-3px);
  box-shadow: var(--shadow-ambient);
}

.node-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.node-name-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
}

.node-flag {
  font-size: 1.25rem;
}

.node-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-main);
}

.ping-tag {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 0.8rem;
  font-weight: 700;
  color: #10b981;
  background: rgba(16, 185, 129, 0.1);
  padding: 2px 8px;
  border-radius: var(--radius-full);
}

.ping-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #10b981;
}

.node-meta {
  display: flex;
  justify-content: space-between;
  font-size: 0.84rem;
  color: var(--text-muted);
  margin-top: 8px;
  padding-top: 10px;
  border-top: 1px dashed var(--border-light);
}

/* 12. 套餐价格对比表 (参考网上真实机场/加速器套餐定价) */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  align-items: stretch;
  perspective: 1200px;
}

.pricing-card {
  background: var(--bg-glass-card);
  border: 1px solid var(--border-specular);
  border-radius: var(--radius-xl);
  padding: 34px 24px;
  box-shadow: var(--shadow-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  transition: transform 0.25s ease-out, box-shadow 0.25s ease-out, border-color 0.25s ease-out;
  display: flex;
  flex-direction: column;
  position: relative;
  transform-style: preserve-3d;
  will-change: transform;
}

.pricing-card:hover {
  box-shadow: var(--shadow-lift);
  border-color: var(--border-card-hover);
}

/* 热门高亮推荐卡片 */
.pricing-card.featured {
  border-color: var(--cobalt-primary);
  background: var(--bg-glass-active);
  box-shadow: 0 16px 36px -4px var(--accent-glow), 0 0 0 1px rgba(29, 78, 216, 0.3) inset;
}

.featured-ribbon {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent-gradient);
  color: #ffffff;
  font-size: 0.76rem;
  font-weight: 700;
  padding: 4px 16px;
  border-radius: var(--radius-full);
  letter-spacing: 0.04em;
  box-shadow: 0 3px 10px var(--badge-glow);
  white-space: nowrap;
}

.pricing-header {
  margin-bottom: 20px;
  text-align: center;
}

.plan-name {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 6px;
}

.plan-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.pricing-amount {
  text-align: center;
  margin: 18px 0 24px;
  padding-bottom: 22px;
  border-bottom: 1px solid var(--border-light);
}

.currency {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--cobalt-primary);
  vertical-align: super;
}

.price {
  font-size: 2.85rem;
  font-weight: 900;
  color: var(--text-main);
  letter-spacing: -0.03em;
}

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

.plan-features {
  list-style: none;
  margin-bottom: 30px;
  flex-grow: 1;
}

.plan-features li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.plan-features li svg {
  color: #10b981;
  flex-shrink: 0;
}

/* 13. 用户评价 (Testimonials) */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}

.review-card {
  background: var(--bg-glass-card);
  border: 1px solid var(--border-specular);
  border-radius: var(--radius-xl);
  padding: 30px;
  box-shadow: var(--shadow-glass);
  backdrop-filter: blur(16px);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all var(--transition-normal);
}

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

.stars {
  color: #f59e0b;
  display: flex;
  gap: 3px;
  margin-bottom: 16px;
}

.review-text {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 22px;
  font-style: italic;
}

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

.author-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--polar-ice);
  border: 1px solid var(--border-specular);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: var(--cobalt-primary);
  font-size: 0.95rem;
}

.author-info h4 {
  font-size: 0.94rem;
  font-weight: 700;
  color: var(--text-main);
}

.author-info p {
  font-size: 0.78rem;
  color: var(--text-faint);
}

/* 14. 常见问题 (FAQ) */
.faq-wrap {
  max-width: 840px;
  margin: 0 auto;
}

.faq-item {
  background: var(--bg-glass-card);
  border: 1px solid var(--border-specular);
  border-radius: var(--radius-lg);
  margin-bottom: 16px;
  overflow: hidden;
  box-shadow: var(--shadow-ambient);
  backdrop-filter: blur(16px);
  transition: all var(--transition-normal);
}

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

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

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

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0, 1, 0, 1);
  padding: 0 26px;
  color: var(--text-muted);
  font-size: 0.96rem;
  line-height: 1.75;
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding-bottom: 24px;
  transition: max-height 0.35s cubic-bezier(1, 0, 1, 0);
}

/* 15. Call to Action Banner */
.cta-banner {
  margin: 40px 0 85px;
  background: var(--accent-gradient);
  border-radius: var(--radius-xl);
  padding: 60px 40px;
  text-align: center;
  color: #ffffff;
  box-shadow: var(--shadow-lift);
  position: relative;
  overflow: hidden;
}

.cta-banner h2 {
  font-size: clamp(1.85rem, 3.6vw, 2.6rem);
  font-weight: 900;
  margin-bottom: 14px;
  letter-spacing: -0.02em;
}

.cta-banner p {
  font-size: 1.05rem;
  max-width: 620px;
  margin: 0 auto 34px;
  opacity: 0.95;
}

.cta-banner .btn-cta-white {
  background: #ffffff;
  color: var(--cobalt-primary) !important;
  font-size: 1.05rem;
  padding: 14px 36px;
  font-weight: 700;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

.cta-banner .btn-cta-white:hover {
  transform: translateY(-2px);
  background: #f8fafc;
}

/* 16. 规范页脚 (Footer) - 严格保留四个指定标题并在新页面展示 */
.site-footer {
  background: var(--bg-surface);
  border-top: 1px solid var(--border-light);
  padding: 55px 0 45px;
  text-align: center;
  transition: background-color var(--transition-slow), border-color var(--transition-slow);
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 40px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.footer-nav-link {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
  transition: color var(--transition-fast);
  position: relative;
  padding: 4px 0;
}

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

.footer-copyright {
  font-size: 0.86rem;
  color: var(--text-faint);
}

/* 17. 推荐资讯子页面与文章专用排版 */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin: 36px 0 60px;
}

.article-card {
  background: var(--bg-glass-card);
  border: 1px solid var(--border-specular);
  border-radius: var(--radius-xl);
  padding: 28px;
  box-shadow: var(--shadow-glass);
  backdrop-filter: blur(16px);
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
}

.article-card:hover {
  transform: translateY(-5px);
  border-color: var(--border-card-hover);
  box-shadow: var(--shadow-lift);
}

.article-tag {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--cobalt-primary);
  background: var(--polar-ice);
  padding: 4px 10px;
  border-radius: var(--radius-full);
  display: inline-block;
  margin-bottom: 14px;
  width: fit-content;
}

.article-card-title {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 12px;
  line-height: 1.4;
  color: var(--text-main);
}

.article-excerpt {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 20px;
  flex-grow: 1;
}

.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.82rem;
  color: var(--text-faint);
  border-top: 1px solid var(--border-light);
  padding-top: 14px;
}

.article-read-more {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--cobalt-primary);
  margin-top: 10px;
  transition: gap var(--transition-fast);
}

.article-card:hover .article-read-more {
  gap: 10px;
}

/* 18. SEO 深度科普长文详情页样式 (Single Article Layout) */
.article-container {
  max-width: 900px;
  margin: 30px auto 80px;
  position: relative;
  z-index: 2;
}

.article-breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

.article-breadcrumb a {
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

.article-breadcrumb a:hover {
  color: var(--cobalt-primary);
}

.article-breadcrumb span.sep {
  color: var(--text-faint);
}

.article-main-header {
  margin-bottom: 32px;
  text-align: left;
}

.article-header-tag {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--cobalt-primary);
  background: var(--polar-ice);
  padding: 5px 14px;
  border-radius: var(--radius-full);
  margin-bottom: 16px;
  border: 1px solid var(--border-light);
}

.article-headline {
  font-size: clamp(1.8rem, 3.8vw, 2.6rem);
  font-weight: 900;
  line-height: 1.3;
  color: var(--text-main);
  letter-spacing: -0.025em;
  margin-bottom: 18px;
}

.article-meta-info {
  display: flex;
  align-items: center;
  gap: 18px;
  flex-wrap: wrap;
  font-size: 0.86rem;
  color: var(--text-faint);
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 20px;
}

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

/* 文章目录 (Table of Contents) */
.article-toc {
  background: var(--bg-glass-card);
  border: 1px solid var(--border-specular);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
  margin-bottom: 36px;
  box-shadow: var(--shadow-glass);
  backdrop-filter: blur(16px);
}

.toc-title {
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.toc-list {
  list-style: none;
  padding-left: 0;
  margin: 0;
}

.toc-item {
  margin-bottom: 8px;
  line-height: 1.5;
}

.toc-item a {
  color: var(--text-muted);
  font-size: 0.94rem;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all var(--transition-fast);
}

.toc-item a:hover {
  color: var(--cobalt-primary);
  transform: translateX(4px);
}

.toc-subitem {
  padding-left: 20px;
  margin-top: 6px;
  font-size: 0.88rem;
}

/* 正文主体排版 */
.article-body {
  background: var(--bg-glass-card);
  border: 1px solid var(--border-specular);
  border-radius: var(--radius-xl);
  padding: 48px;
  box-shadow: var(--shadow-glass);
  backdrop-filter: blur(16px);
  color: var(--text-main);
  line-height: 1.8;
}

.article-body h2 {
  font-size: 1.55rem;
  font-weight: 800;
  color: var(--text-main);
  margin: 42px 0 18px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-light);
  scroll-margin-top: 90px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.article-body h2:first-of-type {
  margin-top: 10px;
}

.article-body h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin: 28px 0 14px;
  scroll-margin-top: 90px;
}

.article-body p {
  font-size: 1.02rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  line-height: 1.85;
}

.article-body ul, .article-body ol {
  margin-bottom: 22px;
  padding-left: 24px;
  color: var(--text-muted);
}

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

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

.article-body a {
  color: var(--cobalt-primary);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 4px;
}

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

/* 信息提示框 */
.article-callout {
  background: var(--polar-ice);
  border-left: 4px solid var(--cobalt-primary);
  padding: 18px 22px;
  border-radius: var(--radius-sm);
  margin: 26px 0;
  font-size: 0.96rem;
  color: var(--text-main);
}

.article-callout.warning {
  border-left-color: #f59e0b;
  background: rgba(245, 158, 11, 0.08);
}

/* 文章内嵌入的对比表格 */
.article-table-wrap {
  width: 100%;
  overflow-x: auto;
  margin: 26px 0;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-card);
}

.article-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.92rem;
}

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

.article-table td {
  padding: 13px 18px;
  border-bottom: 1px solid var(--border-light);
  color: var(--text-muted);
}

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

/* 文章专用 CTA 卡片 */
.article-cta-box {
  background: var(--accent-gradient);
  color: #ffffff;
  padding: 36px 30px;
  border-radius: var(--radius-lg);
  margin: 40px 0;
  text-align: center;
  box-shadow: var(--shadow-lift);
}

.article-cta-box h3 {
  color: #ffffff;
  font-size: 1.45rem;
  font-weight: 800;
  margin-bottom: 10px;
}

.article-cta-box p {
  color: rgba(255, 255, 255, 0.92);
  font-size: 0.98rem;
  max-width: 620px;
  margin: 0 auto 22px;
}

.article-cta-box .btn-white {
  background: #ffffff;
  color: var(--cobalt-primary) !important;
  font-weight: 700;
  padding: 12px 30px;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.15);
}

.article-cta-box .btn-white:hover {
  background: #f8fafc;
  transform: translateY(-2px);
}

/* 常见问题 (Article FAQ Section) */
.article-faq-section {
  margin-top: 45px;
  border-top: 1px solid var(--border-light);
  padding-top: 36px;
}

.article-faq-item {
  margin-bottom: 22px;
}

.article-faq-item h4 {
  font-size: 1.12rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.article-faq-item p {
  font-size: 0.96rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* 相关阅读推荐 (Related Articles) */
.related-articles-section {
  margin-top: 55px;
  border-top: 1px solid var(--border-light);
  padding-top: 36px;
}

.related-title {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 22px;
  display: flex;
  align-items: center;
  gap: 8px;
}

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

.related-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 20px;
  transition: all var(--transition-fast);
  display: flex;
  flex-direction: column;
}

.related-card:hover {
  border-color: var(--cobalt-primary);
  transform: translateY(-3px);
  box-shadow: var(--shadow-ambient);
}

.related-card h5 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 8px;
  line-height: 1.45;
}

.related-card p {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 12px;
  flex-grow: 1;
}

.related-link {
  font-size: 0.84rem;
  font-weight: 700;
  color: var(--cobalt-primary);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* 18. 响应式与移动端深度适配 */
@media (max-width: 1024px) {
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .nodes-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .acrylic-stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

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

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

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

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

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

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

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

  .tabs-nav-container {
    overflow-x: auto;
    justify-content: flex-start;
    padding: 4px;
  }

  .tab-btn {
    padding: 8px 14px;
    font-size: 0.85rem;
    white-space: nowrap;
  }

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

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

  .hero-cta-group .btn {
    width: 100%;
  }
}