:root {
  --bg-primary: #07090e;
  --bg-secondary: #0d111a;
  --bg-card: rgba(18, 24, 38, 0.75);
  --bg-card-hover: rgba(26, 34, 52, 0.9);
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-glow: rgba(99, 102, 241, 0.45);
  --accent-purple: #7c3aed;
  --accent-blue: #2563eb;
  --accent-cyan: #06b6d4;
  --accent-green: #10b981;
  --accent-amber: #f59e0b;
  --accent-rose: #ec4899;
  --gradient-obsidian: linear-gradient(135deg, #1e1b4b 0%, #0f172a 50%, #07090e 100%);
  --gradient-cta: linear-gradient(135deg, #6366f1 0%, #a855f7 50%, #ec4899 100%);
  --gradient-cta-hover: linear-gradient(135deg, #4f46e5 0%, #9333ea 50%, #db2777 100%);
  --gradient-gold: linear-gradient(135deg, #f59e0b 0%, #ec4899 50%, #8b5cf6 100%);
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --shadow-glow: 0 0 35px rgba(99, 102, 241, 0.28);
  --shadow-card: 0 10px 30px -10px rgba(0, 0, 0, 0.65);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
}

body {
  min-height: 100vh;
  position: relative;
  overflow-x: hidden;
  background: radial-gradient(circle at 50% -20%, rgba(99, 102, 241, 0.18), transparent 70%),
              radial-gradient(circle at 10% 40%, rgba(147, 51, 234, 0.1), transparent 50%),
              radial-gradient(circle at 90% 70%, rgba(6, 182, 212, 0.1), transparent 50%),
              var(--bg-primary);
}

/* 顶部星辰极光流光条 */
.top-glow-bar {
  height: 2px;
  width: 100%;
  background: linear-gradient(90deg, transparent 0%, #6366f1 20%, #06b6d4 50%, #ec4899 80%, transparent 100%);
  position: fixed;
  top: 0;
  left: 0;
  z-index: 1001;
}

/* 容器布局 */
.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 24px;
}

/* 页面顶部导航 */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  background: rgba(7, 9, 14, 0.8);
  border-bottom: 1px solid var(--border-subtle);
  transition: all 0.3s ease;
}

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

/* 品牌 Logo 与互动效果 */
.logo-interactive {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  cursor: pointer;
  user-select: none;
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

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

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

.logo-icon-box {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  background: linear-gradient(135deg, #4f46e5, #9333ea);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 22px rgba(99, 102, 241, 0.55);
  position: relative;
  overflow: hidden;
}

.logo-icon-box::after {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: linear-gradient(45deg, transparent, rgba(255, 255, 255, 0.35), transparent);
  transform: rotate(45deg);
  animation: logo-shimmer 4s infinite linear;
}

@keyframes logo-shimmer {
  0% { transform: translateY(-100%) rotate(45deg); }
  20%, 100% { transform: translateY(100%) rotate(45deg); }
}

.logo-icon-svg {
  width: 24px;
  height: 24px;
  fill: #ffffff;
  position: relative;
  z-index: 2;
}

.logo-text-group {
  display: flex;
  flex-direction: column;
}

.logo-title {
  font-size: 1.28rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  background: linear-gradient(90deg, #ffffff, #c7d2fe);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.logo-badge {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.8px;
  color: var(--accent-cyan);
  text-transform: uppercase;
}

/* 导航链接目录 */
.nav-menu {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: all 0.2s ease;
  position: relative;
  padding: 6px 0;
}

.nav-link:hover {
  color: #ffffff;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--accent-cyan);
  transition: width 0.25s ease;
}

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

.nav-right-group {
  display: flex;
  align-items: center;
  gap: 16px;
}

.nav-cta-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 22px;
  font-size: 0.92rem;
  font-weight: 700;
  color: #ffffff;
  background: var(--gradient-cta);
  border-radius: var(--radius-full);
  text-decoration: none;
  box-shadow: 0 4px 18px rgba(99, 102, 241, 0.35);
  transition: all 0.3s ease;
}

.nav-cta-btn:hover {
  background: var(--gradient-cta-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(168, 85, 247, 0.45);
}

/* 移动端汉堡切换按钮与抽屉菜单 */
.mobile-menu-toggle {
  display: none;
  width: 40px;
  height: 40px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border-subtle);
  border-radius: 10px;
  color: #ffffff;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  outline: none;
}

.mobile-menu-toggle svg {
  width: 22px;
  height: 22px;
}

.mobile-nav-drawer {
  display: none;
  position: absolute;
  top: 72px;
  left: 0;
  width: 100%;
  background: rgba(10, 13, 20, 0.98);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-subtle);
  padding: 20px 24px 28px;
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.7);
}

.mobile-nav-drawer.open {
  display: block;
  animation: drawer-fade-in 0.25s ease forwards;
}

@keyframes drawer-fade-in {
  from { opacity: 0; transform: translateY(-10px); }
  to { opacity: 1; transform: translateY(0); }
}

.mobile-menu-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 20px;
}

.mobile-menu-list a {
  color: var(--text-main);
  text-decoration: none;
  font-size: 1.05rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

/* 章节通用样式 */
.section-wrapper {
  padding: 100px 0;
  position: relative;
}

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

.badge-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  background: rgba(99, 102, 241, 0.12);
  border: 1px solid rgba(99, 102, 241, 0.28);
  border-radius: var(--radius-full);
  font-size: 0.82rem;
  font-weight: 700;
  color: #a5b4fc;
  margin-bottom: 18px;
  letter-spacing: 0.5px;
}

.badge-tag span.dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--accent-green);
  box-shadow: 0 0 10px var(--accent-green);
  animation: pulse-dot 2s infinite ease-in-out;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.85); }
}

.section-title {
  font-size: 2.35rem;
  font-weight: 800;
  color: #ffffff;
  line-height: 1.3;
  margin-bottom: 18px;
  letter-spacing: -0.5px;
}

.section-subtitle {
  font-size: 1.08rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* 主视觉区 (Hero Section) 左右两栏分布布局 */
.hero-section {
  padding: 90px 0 80px;
  position: relative;
  overflow: hidden;
}

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

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

.hero-headline {
  font-size: 3.35rem;
  font-weight: 900;
  line-height: 1.18;
  margin-bottom: 22px;
  letter-spacing: -1.2px;
}

.brand-hero-name {
  background: linear-gradient(135deg, #ffffff 10%, #c7d2fe 60%, #818cf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: block;
  font-size: 3.5rem;
  margin-bottom: 6px;
}

.gradient-text {
  background: linear-gradient(135deg, #ffffff 20%, #a5b4fc 50%, #38bdf8 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.gradient-text-accent {
  background: linear-gradient(135deg, #a855f7 0%, #ec4899 50%, #f43f5e 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subhead {
  font-size: 1.12rem;
  color: var(--text-muted);
  line-height: 1.75;
  margin-bottom: 34px;
  max-width: 620px;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 38px;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 15px 32px;
  font-size: 1.05rem;
  font-weight: 700;
  color: #ffffff;
  background: var(--gradient-cta);
  border-radius: var(--radius-full);
  text-decoration: none;
  box-shadow: 0 10px 28px rgba(99, 102, 241, 0.4);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  border: 1px solid rgba(255, 255, 255, 0.15);
  cursor: pointer;
}

.btn-primary:hover {
  background: var(--gradient-cta-hover);
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 14px 35px rgba(168, 85, 247, 0.55);
}

.btn-recommend {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 15px 28px;
  font-size: 1.02rem;
  font-weight: 700;
  color: #ffffff;
  background: var(--gradient-gold);
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: var(--radius-full);
  text-decoration: none;
  box-shadow: 0 10px 28px rgba(245, 158, 11, 0.35);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  overflow: hidden;
  cursor: pointer;
}

.btn-recommend:hover {
  background: linear-gradient(135deg, #d97706 0%, #db2777 50%, #7c3aed 100%);
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 14px 35px rgba(236, 72, 153, 0.5);
  color: #ffffff;
}

.btn-recommend svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 15px 28px;
  font-size: 1.02rem;
  font-weight: 600;
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-full);
  text-decoration: none;
  backdrop-filter: blur(10px);
  transition: all 0.3s ease;
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.25);
  transform: translateY(-2px);
  color: #ffffff;
}

/* Hero 右侧动态高科技图卡 (Cyber Radar Dashboard) */
.hero-right-col {
  position: relative;
}

.cyber-dashboard-card {
  background: linear-gradient(160deg, rgba(22, 29, 47, 0.85) 0%, rgba(13, 17, 26, 0.95) 100%);
  border: 1px solid rgba(99, 102, 241, 0.3);
  border-radius: 24px;
  padding: 28px;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 20px 50px -10px rgba(0, 0, 0, 0.8),
              0 0 30px rgba(99, 102, 241, 0.2);
  position: relative;
  overflow: hidden;
  animation: float-slow 6s ease-in-out infinite;
}

@keyframes float-slow {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

.cyber-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: 20px;
}

.cyber-status-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--accent-green);
  background: rgba(16, 185, 129, 0.12);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  border: 1px solid rgba(16, 185, 129, 0.25);
}

.cyber-status-badge .dot-live {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-green);
  box-shadow: 0 0 8px var(--accent-green);
  animation: live-blink 1.5s infinite;
}

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

.cyber-terminal-id {
  font-family: monospace;
  font-size: 0.78rem;
  color: var(--text-dim);
}

/* 动态波形与雷达图 */
.cyber-waveform-panel {
  background: rgba(0, 0, 0, 0.35);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: 16px;
  padding: 20px;
  margin-bottom: 20px;
  position: relative;
  overflow: hidden;
}

.waveform-meta {
  display: flex;
  justify-content: space-between;
  margin-bottom: 14px;
}

.waveform-label {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.waveform-speed {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--accent-cyan);
  font-feature-settings: "tnum";
}

.waveform-bars-container {
  display: flex;
  align-items: flex-end;
  gap: 6px;
  height: 60px;
  padding-top: 10px;
}

.waveform-bar {
  flex: 1;
  background: linear-gradient(180deg, var(--accent-cyan) 0%, rgba(99, 102, 241, 0.4) 100%);
  border-radius: 4px;
  animation: bar-dance 2s infinite ease-in-out;
}

.waveform-bar:nth-child(2) { animation-delay: 0.2s; }
.waveform-bar:nth-child(3) { animation-delay: 0.4s; }
.waveform-bar:nth-child(4) { animation-delay: 0.6s; }
.waveform-bar:nth-child(5) { animation-delay: 0.1s; }
.waveform-bar:nth-child(6) { animation-delay: 0.3s; }
.waveform-bar:nth-child(7) { animation-delay: 0.5s; }
.waveform-bar:nth-child(8) { animation-delay: 0.7s; }
.waveform-bar:nth-child(9) { animation-delay: 0.25s; }
.waveform-bar:nth-child(10) { animation-delay: 0.45s; }
.waveform-bar:nth-child(11) { animation-delay: 0.65s; }
.waveform-bar:nth-child(12) { animation-delay: 0.35s; }

@keyframes bar-dance {
  0%, 100% { height: 25%; }
  50% { height: 95%; }
}

/* 节点实时延迟监控网格 */
.cyber-node-pills {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
}

.node-pill-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 12px;
  transition: all 0.2s ease;
}

.node-pill-item:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(99, 102, 241, 0.3);
}

.node-city {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  color: #ffffff;
}

.node-flag {
  font-size: 1rem;
}

.node-latency {
  font-size: 0.78rem;
  font-weight: 700;
  color: #34d399;
  font-family: monospace;
}

/* Hero 数据指标条 */
.hero-stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  backdrop-filter: blur(16px);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-card);
  margin-top: 50px;
}

.stat-item {
  text-align: center;
  padding: 8px 12px;
  border-right: 1px solid var(--border-subtle);
}

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

.stat-value {
  font-size: 1.8rem;
  font-weight: 800;
  color: #ffffff;
  font-feature-settings: "tnum";
  margin-bottom: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
}

.stat-value .unit {
  font-size: 1rem;
  color: var(--accent-cyan);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-dim);
  font-weight: 500;
}

/* 核心优势卡片（细节质感深度增强） */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  position: relative;
  overflow: hidden;
  transition: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  display: flex;
  flex-direction: column;
}

.feature-card-number {
  position: absolute;
  top: 24px;
  right: 28px;
  font-size: 2.5rem;
  font-weight: 900;
  color: rgba(255, 255, 255, 0.04);
  font-family: monospace;
  pointer-events: none;
  transition: color 0.3s ease;
}

.feature-card:hover .feature-card-number {
  color: rgba(99, 102, 241, 0.18);
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, #6366f1, #06b6d4, #ec4899);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-8px);
  border-color: var(--border-glow);
  background: var(--bg-card-hover);
  box-shadow: var(--shadow-glow);
}

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

.feature-icon-wrapper {
  width: 62px;
  height: 62px;
  border-radius: 18px;
  background: linear-gradient(135deg, rgba(99, 102, 241, 0.18), rgba(6, 182, 212, 0.1));
  border: 1px solid rgba(99, 102, 241, 0.35);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  color: #a5b4fc;
}

.feature-icon-wrapper svg {
  width: 30px;
  height: 30px;
}

.feature-title {
  font-size: 1.35rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 14px;
}

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

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

.feature-tag-item {
  font-size: 0.78rem;
  padding: 5px 12px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-sm);
  color: #cbd5e1;
  font-weight: 500;
}

/* 流媒体与 AI 支持图卡（高清官方品牌配色与精致图标） */
.support-cards-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
}

.support-category-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 38px;
  position: relative;
  overflow: hidden;
  transition: all 0.3s ease;
}

.support-category-card:hover {
  border-color: rgba(6, 182, 212, 0.4);
  box-shadow: 0 0 35px rgba(6, 182, 212, 0.18);
}

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

.support-cat-icon {
  width: 52px;
  height: 52px;
  border-radius: 16px;
  background: rgba(6, 182, 212, 0.12);
  border: 1px solid rgba(6, 182, 212, 0.35);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-cyan);
}

.support-cat-icon svg {
  width: 28px;
  height: 28px;
}

.support-cat-title {
  font-size: 1.35rem;
  font-weight: 800;
  color: #ffffff;
}

.support-cat-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 24px;
}

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

.service-badge-pill {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-md);
  transition: all 0.25s ease;
}

.service-badge-pill:hover {
  background: rgba(255, 255, 255, 0.08);
  transform: translateX(3px);
  border-color: rgba(255, 255, 255, 0.18);
}

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

.service-brand-icon {
  width: 26px;
  height: 26px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.service-brand-icon svg {
  width: 100%;
  height: 100%;
}

.service-name {
  font-size: 0.9rem;
  font-weight: 600;
  color: #f1f5f9;
}

.service-status {
  font-size: 0.72rem;
  padding: 3px 8px;
  background: rgba(16, 185, 129, 0.15);
  color: #34d399;
  border-radius: 6px;
  font-weight: 700;
  white-space: nowrap;
}

/* 套餐价格对比表（参考网上真实机场套餐体系：4 档精细化阶梯） */
.pricing-grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 34px 24px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

.pricing-card.featured {
  background: linear-gradient(180deg, rgba(32, 41, 68, 0.9) 0%, rgba(18, 24, 38, 0.98) 100%);
  border-color: rgba(168, 85, 247, 0.6);
  box-shadow: 0 0 45px rgba(168, 85, 247, 0.25);
  transform: scale(1.03);
  z-index: 2;
}

.popular-badge {
  position: absolute;
  top: -13px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(90deg, #ec4899, #8b5cf6);
  color: #ffffff;
  padding: 4px 16px;
  border-radius: var(--radius-full);
  font-size: 0.76rem;
  font-weight: 700;
  letter-spacing: 0.5px;
  box-shadow: 0 4px 12px rgba(236, 72, 153, 0.45);
  white-space: nowrap;
}

.savings-pill {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  color: #34d399;
  background: rgba(16, 185, 129, 0.15);
  padding: 2px 8px;
  border-radius: 4px;
  margin-top: 4px;
}

.pricing-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-glow);
}

.pricing-card.featured:hover {
  transform: scale(1.03) translateY(-6px);
}

.plan-name {
  font-size: 1.3rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 6px;
}

.plan-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  min-height: 38px;
}

.plan-price-box {
  display: flex;
  flex-direction: column;
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-subtle);
}

.price-main-row {
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.currency {
  font-size: 1.2rem;
  font-weight: 700;
  color: #ffffff;
}

.amount {
  font-size: 2.7rem;
  font-weight: 900;
  color: #ffffff;
  letter-spacing: -1px;
}

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

.plan-features-list {
  list-style: none;
  margin-bottom: 28px;
  flex-grow: 1;
}

.plan-features-list li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.88rem;
  color: #cbd5e1;
  margin-bottom: 12px;
}

.plan-features-list li svg {
  width: 17px;
  height: 17px;
  color: var(--accent-green);
  flex-shrink: 0;
}

.pricing-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  padding: 13px;
  font-size: 0.98rem;
  font-weight: 700;
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: all 0.3s ease;
  cursor: pointer;
}

.pricing-btn-primary {
  background: var(--gradient-cta);
  color: #ffffff;
  box-shadow: 0 4px 18px rgba(99, 102, 241, 0.4);
}

.pricing-btn-primary:hover {
  background: var(--gradient-cta-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(168, 85, 247, 0.5);
}

.pricing-btn-outline {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-subtle);
  color: #ffffff;
}

.pricing-btn-outline:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.25);
  transform: translateY(-2px);
}

/* SEO 技术专栏图卡板块 (位于价格板块下方) */
.articles-category-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 40px;
}

.category-tab-btn {
  padding: 8px 18px;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s ease;
}

.category-tab-btn:hover,
.category-tab-btn.active {
  background: var(--gradient-cta);
  color: #ffffff;
  border-color: transparent;
  box-shadow: 0 4px 16px rgba(99, 102, 241, 0.4);
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 26px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.article-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, #6366f1, #06b6d4, #ec4899);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.article-card:hover {
  transform: translateY(-6px);
  background: var(--bg-card-hover);
  border-color: var(--border-glow);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5), 0 0 20px rgba(99, 102, 241, 0.2);
}

.article-card:hover::after {
  opacity: 1;
}

.article-top-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}

.article-tag-chip {
  font-size: 0.72rem;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  background: rgba(99, 102, 241, 0.15);
  color: #a5b4fc;
  border: 1px solid rgba(99, 102, 241, 0.3);
}

.article-read-time {
  font-size: 0.76rem;
  color: var(--text-dim);
}

.article-card-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: #ffffff;
  line-height: 1.45;
  margin-bottom: 12px;
  transition: color 0.2s ease;
}

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

.article-card-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 20px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  text-overflow: ellipsis;
}

.article-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 14px;
  margin-top: auto;
}

.article-date {
  font-size: 0.78rem;
  color: var(--text-dim);
}

.article-read-more {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-cyan);
  display: flex;
  align-items: center;
  gap: 4px;
  transition: transform 0.2s ease;
}

.article-card:hover .article-read-more {
  transform: translateX(4px);
}

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

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 30px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.3s ease;
}

.review-card:hover {
  transform: translateY(-5px);
  border-color: rgba(255, 255, 255, 0.2);
  background: var(--bg-card-hover);
}

.review-stars {
  display: flex;
  gap: 4px;
  color: #fbbf24;
  margin-bottom: 16px;
}

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

.review-text {
  font-size: 0.95rem;
  color: #e2e8f0;
  line-height: 1.7;
  margin-bottom: 22px;
  font-style: italic;
}

.reviewer-meta {
  display: flex;
  align-items: center;
  gap: 14px;
  border-top: 1px solid var(--border-subtle);
  padding-top: 16px;
}

.reviewer-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, #4f46e5, #06b6d4);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #ffffff;
  font-size: 1rem;
}

.reviewer-info-box {
  display: flex;
  flex-direction: column;
}

.reviewer-name {
  font-size: 0.92rem;
  font-weight: 700;
  color: #ffffff;
}

.reviewer-role {
  font-size: 0.78rem;
  color: var(--text-dim);
}

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

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all 0.3s ease;
}

.faq-item:hover {
  border-color: rgba(255, 255, 255, 0.2);
}

.faq-summary {
  padding: 20px 24px;
  font-size: 1.05rem;
  font-weight: 600;
  color: #ffffff;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
  list-style: none;
}

.faq-summary::-webkit-details-marker {
  display: none;
}

.faq-summary svg {
  width: 20px;
  height: 20px;
  color: var(--accent-cyan);
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

details[open] .faq-summary svg {
  transform: rotate(180deg);
}

details[open] {
  background: var(--bg-card-hover);
  border-color: var(--border-glow);
}

.faq-answer {
  padding: 0 24px 22px;
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.7;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  margin-top: 4px;
  padding-top: 16px;
}

/* 右侧浮动章节导航控制器 (Side Chapter Navigator) */
.side-chapter-navigator {
  position: fixed;
  right: 24px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 999;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  background: rgba(13, 17, 26, 0.8);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  padding: 12px 8px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-subtle);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.55);
  transition: all 0.3s ease;
}

.nav-arrow-btn {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
  position: relative;
  outline: none;
}

.nav-arrow-btn svg {
  width: 18px;
  height: 18px;
  transition: transform 0.2s ease;
}

.nav-arrow-btn:hover {
  background: var(--gradient-cta);
  border-color: transparent;
  transform: scale(1.15);
  box-shadow: 0 0 16px rgba(168, 85, 247, 0.6);
}

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

.nav-dots-container {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 6px 0;
}

.nav-dot-item {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.25);
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
}

.nav-dot-item:hover,
.nav-dot-item.active {
  background: var(--accent-cyan);
  transform: scale(1.4);
  box-shadow: 0 0 8px var(--accent-cyan);
}

.nav-arrow-btn .tooltip,
.nav-dot-item .tooltip {
  position: absolute;
  right: 48px;
  top: 50%;
  transform: translateY(-50%) translateX(10px);
  background: #0f172a;
  color: #ffffff;
  padding: 5px 12px;
  border-radius: 6px;
  font-size: 0.75rem;
  font-weight: 600;
  white-space: nowrap;
  pointer-events: none;
  opacity: 0;
  transition: all 0.2s ease;
  border: 1px solid var(--border-subtle);
  box-shadow: 0 4px 12px rgba(0,0,0,0.4);
}

.nav-arrow-btn:hover .tooltip,
.nav-dot-item:hover .tooltip {
  opacity: 1;
  transform: translateY(-50%) translateX(0);
}

/* 页脚：严格只保留 4 个标题，并在新页面中打开展示 */
.site-footer {
  background: #05070a;
  border-top: 1px solid var(--border-subtle);
  padding: 48px 0 36px;
  margin-top: 80px;
}

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

.footer-link-item a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 1.02rem;
  font-weight: 600;
  transition: all 0.25s ease;
  position: relative;
  padding: 4px 0;
}

.footer-link-item a:hover {
  color: var(--accent-cyan);
}

.footer-link-item a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0%;
  height: 2px;
  background: var(--accent-cyan);
  transition: width 0.25s ease;
}

.footer-link-item a:hover::after {
  width: 100%;
}

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

.footer-copyright a {
  color: var(--text-muted);
  text-decoration: none;
}

/* 页脚资深 SEO 与安全背书增强模块 */
.footer-trust-badges {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 24px;
  margin: 28px 0 24px;
  padding: 16px 20px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-md);
}

.trust-badge-item {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.trust-badge-item svg {
  width: 16px;
  height: 16px;
  color: var(--accent-cyan);
  flex-shrink: 0;
}

.footer-seo-keywords {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 20px;
  font-size: 0.82rem;
  color: var(--text-dim);
}

.footer-seo-keywords span.label {
  color: var(--text-muted);
  font-weight: 600;
}

.footer-seo-keywords a {
  color: #94a3b8;
  text-decoration: none;
  transition: all 0.2s ease;
  padding: 3px 8px;
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.06);
}

.footer-seo-keywords a:hover {
  color: #ffffff;
  border-color: var(--accent-cyan);
  background: rgba(6, 182, 212, 0.1);
}

.footer-pbn-links {
  text-align: center;
  margin: 18px 0 14px;
  font-size: 0.88rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 12px;
}

.footer-pbn-links .pbn-label {
  color: var(--text-dim);
  font-weight: 600;
}

.footer-pbn-links .pbn-link-item {
  color: #38bdf8;
  text-decoration: none;
  font-weight: 600;
  padding: 4px 12px;
  background: rgba(56, 189, 248, 0.08);
  border: 1px solid rgba(56, 189, 248, 0.22);
  border-radius: var(--radius-sm);
  transition: all 0.25s ease;
}

.footer-pbn-links .pbn-link-item:hover {
  color: #ffffff;
  background: rgba(56, 189, 248, 0.22);
  border-color: var(--accent-cyan);
  box-shadow: 0 0 14px rgba(6, 182, 212, 0.4);
  transform: translateY(-1px);
}

.footer-pbn-links .pbn-separator {
  color: rgba(255, 255, 255, 0.15);
}

/* 响应式媒体查询适配 */
@media (max-width: 1100px) {
  .hero-two-columns {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .hero-left-col {
    text-align: center;
  }
  .hero-subhead {
    margin-left: auto;
    margin-right: auto;
  }
  .hero-cta-group {
    justify-content: center;
  }
  .pricing-grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 900px) {
  .nav-menu {
    display: none;
  }
  .mobile-menu-toggle {
    display: flex;
  }
  .features-grid,
  .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .hero-headline {
    font-size: 2.25rem;
    letter-spacing: -0.8px;
  }
  .brand-hero-name {
    font-size: 2.6rem;
  }
  .hero-subhead {
    font-size: 1.02rem;
  }
  .hero-cta-group {
    flex-direction: column;
    width: 100%;
    gap: 14px;
  }
  .btn-primary, .btn-secondary, .btn-recommend {
    width: 100%;
    min-height: 52px;
    font-size: 1.05rem;
  }
  .hero-stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin-top: 36px;
  }
  .stat-item:nth-child(2) {
    border-right: none;
  }
  .features-grid,
  .support-cards-grid,
  .pricing-grid-4,
  .reviews-grid {
    grid-template-columns: 1fr;
  }
  .service-badges-grid {
    grid-template-columns: 1fr;
  }
  .side-chapter-navigator {
    right: 12px;
    padding: 8px 6px;
    transform: translateY(-50%) scale(0.9);
  }
  .footer-nav-links {
    flex-wrap: wrap;
    gap: 20px 28px;
  }
  .section-title {
    font-size: 1.85rem;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }
  .hero-section {
    padding: 50px 0 40px;
  }
  .hero-stats-grid {
    grid-template-columns: 1fr;
  }
  .stat-item {
    border-right: none;
    border-bottom: 1px solid var(--border-subtle);
    padding-bottom: 12px;
  }
  .stat-item:last-child {
    border-bottom: none;
    padding-bottom: 0;
  }
  .footer-nav-links {
    flex-direction: column;
    gap: 16px;
  }
}