/* ==========================================================================
   Nexitally (奶昔机场) - Benthic Champagne-Effervescence Luxury UI
   Sovereign Apex of Dedicated Transit | 纯原生 CSS3 | 响应式双模式
   深海深渊午夜黑 (#06080f) + 磨砂牛奶白 + 拉丝香槟金 (#d4af37)
   ========================================================================== */

:root {
  /* 默认白天模式 (Sovereign Champagne Pearl 奢华珠光香槟模式) */
  --bg-primary: #f8f6f0;
  --bg-secondary: #ffffff;
  --bg-tertiary: #f1ede2;
  --bg-obsidian: rgba(255, 255, 255, 0.88);
  --bg-glass: rgba(248, 246, 240, 0.82);

  --text-main: #0c101c;
  --text-muted: #3e4859;
  --text-subtle: #626e82;

  --champagne-gold: #b89730;
  --champagne-gold-light: #d8b858;
  --champagne-gold-glow: rgba(184, 151, 48, 0.22);
  --champagne-bubble: rgba(184, 151, 48, 0.35);

  --frosted-milk: #ffffff;
  --bioluminescent-core: rgba(255, 255, 255, 0.95);
  --bioluminescent-glow: rgba(184, 151, 48, 0.18);
  --zero-loss-emerald: #059669;

  --border-light: rgba(12, 16, 28, 0.08);
  --border-gold: rgba(184, 151, 48, 0.32);
  --border-gold-hover: #b89730;
  --border-glass: rgba(255, 255, 255, 0.7);

  --gradient-gold: linear-gradient(135deg, #d4af37 0%, #aa8012 100%);
  --gradient-gold-text: linear-gradient(135deg, #a67c1e 0%, #d4af37 50%, #8a6512 100%);
  --gradient-hero-bg: radial-gradient(circle at 50% -10%, rgba(212, 175, 55, 0.12) 0%, rgba(248, 246, 240, 0) 75%);

  --shadow-sm: 0 2px 6px rgba(12, 16, 28, 0.04);
  --shadow-md: 0 8px 20px rgba(12, 16, 28, 0.06);
  --shadow-gold: 0 8px 30px rgba(184, 151, 48, 0.2);
  --shadow-card: 0 16px 36px -8px rgba(12, 16, 28, 0.08);

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  --nav-height: 74px;
  --transition-normal: 0.32s cubic-bezier(0.16, 1, 0.3, 1);
}

/* 夜间深渊午夜模式 (Benthic Trench Midnight - 极致深邃奢华) */
[data-theme="dark"] {
  --bg-primary: #06080f; /* 深海深渊午夜黑 */
  --bg-secondary: #0a0d18;
  --bg-tertiary: #101524;
  --bg-obsidian: rgba(10, 13, 24, 0.78); /* 熏黑黑曜石质感 */
  --bg-glass: rgba(6, 8, 15, 0.85);

  --text-main: #f5f7fa; /* 磨砂牛奶白主文字 */
  --text-muted: #9ba6b8;
  --text-subtle: #677488;

  --champagne-gold: #d4af37; /* 拉丝香槟金 */
  --champagne-gold-light: #f3e5ab;
  --champagne-gold-glow: rgba(212, 175, 55, 0.35);
  --champagne-bubble: rgba(212, 175, 55, 0.45);

  --frosted-milk: rgba(245, 247, 250, 0.96);
  --bioluminescent-core: rgba(215, 235, 255, 0.07);
  --bioluminescent-glow: rgba(212, 175, 55, 0.28);
  --zero-loss-emerald: #10b981;

  --border-light: rgba(255, 255, 255, 0.06);
  --border-gold: rgba(212, 175, 55, 0.26);
  --border-gold-hover: #d4af37;
  --border-glass: rgba(255, 255, 255, 0.09);

  --gradient-gold: linear-gradient(135deg, #f3e5ab 0%, #d4af37 50%, #aa8012 100%);
  --gradient-gold-text: linear-gradient(135deg, #ffffff 0%, #f3e5ab 35%, #d4af37 100%);
  --gradient-hero-bg: radial-gradient(circle at 50% -10%, rgba(212, 175, 55, 0.16) 0%, rgba(6, 8, 15, 0) 75%);

  --shadow-sm: 0 2px 6px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.55);
  --shadow-gold: 0 8px 32px rgba(212, 175, 55, 0.28);
  --shadow-card: 0 20px 48px -10px rgba(0, 0, 0, 0.7);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + 24px);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.65;
  overflow-x: hidden;
  position: relative;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  background-image: var(--gradient-hero-bg);
  background-repeat: no-repeat;
  background-position: top center;
  min-height: 100vh;
}

/* 深海香槟微气泡动效画布 (Canvas) */
#effervescenceCanvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 0;
  opacity: 0.85;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-normal), border-color var(--transition-normal), transform var(--transition-normal);
}

img, svg {
  vertical-align: middle;
  display: inline-block;
}

/* 布局容器 */
.container {
  width: 100%;
  max-width: 1220px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 26px;
  padding-right: 26px;
  position: relative;
  z-index: 1;
}

.section {
  padding: 96px 0;
  position: relative;
  z-index: 1;
}

/* 顶部页眉导航栏 */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-light);
  z-index: 1000;
  transition: all var(--transition-normal);
}

.navbar .nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
  color: var(--text-main);
}

.brand-icon {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-sm);
  background: var(--gradient-gold);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #06080f;
  box-shadow: 0 4px 14px var(--champagne-gold-glow);
  font-weight: 800;
}

/* 导航目录 (首页 + 核心板块 + 推荐资讯入口) */
.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
  list-style: none;
}

.nav-links a {
  font-size: 0.94rem;
  font-weight: 500;
  color: var(--text-muted);
  position: relative;
  padding: 8px 4px;
  transition: color var(--transition-normal);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--champagne-gold);
}

.nav-links a::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: var(--champagne-gold);
  border-radius: 2px;
  transition: width var(--transition-normal);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 80%;
}

/* 推荐资讯特殊微高亮标识 */
.nav-badge-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--champagne-gold) !important;
}

.nav-badge-pulse {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--champagne-gold);
  box-shadow: 0 0 8px var(--champagne-gold);
  animation: pulseGold 2s infinite ease-in-out;
}

@keyframes pulseGold {
  0%, 100% { transform: scale(1); opacity: 0.7; }
  50% { transform: scale(1.4); opacity: 1; }
}

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

/* 精致专业化透明昼夜模式切换按钮 */
.theme-toggle-btn {
  background: var(--bg-obsidian);
  border: 1px solid var(--border-gold);
  width: 42px;
  height: 42px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--champagne-gold);
  transition: all var(--transition-normal);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

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

.theme-toggle-btn svg {
  width: 19px;
  height: 19px;
  transition: transform 0.45s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.35s ease;
}

.icon-sun {
  position: absolute;
  opacity: 1;
  transform: rotate(0deg) scale(1);
}

.icon-moon {
  position: absolute;
  opacity: 0;
  transform: rotate(-90deg) scale(0.5);
}

[data-theme="dark"] .icon-sun {
  opacity: 0;
  transform: rotate(90deg) scale(0.5);
}

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

/* 按钮规范 (严格呼吁性 CTA) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  font-weight: 600;
  font-size: 0.96rem;
  padding: 13px 26px;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-normal);
  text-align: center;
  white-space: nowrap;
  border: 1px solid transparent;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: var(--gradient-gold);
  color: #06080f !important;
  font-weight: 700;
  border: 1px solid rgba(255, 255, 255, 0.3);
  box-shadow: 0 4px 16px var(--champagne-gold-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 26px var(--shadow-gold);
  filter: brightness(1.06);
}

.btn-secondary {
  background: var(--bg-obsidian);
  color: var(--text-main);
  border: 1px solid var(--border-gold);
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  border-color: var(--border-gold-hover);
  color: var(--champagne-gold);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.btn-sm {
  padding: 8px 18px;
  font-size: 0.88rem;
  border-radius: var(--radius-sm);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 1.05rem;
  border-radius: var(--radius-md);
}

.btn-block {
  width: 100%;
}

/* 徽章 Badge */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: var(--radius-full);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  white-space: nowrap;
}

.badge-gold {
  background: rgba(212, 175, 55, 0.1);
  color: var(--champagne-gold);
  border: 1px solid var(--border-gold);
}

.badge-emerald {
  background: rgba(16, 185, 129, 0.12);
  color: var(--zero-loss-emerald);
  border: 1px solid rgba(16, 185, 129, 0.28);
}

/* 主视觉区 (Hero Section) */
.hero-section {
  padding-top: calc(var(--nav-height) + 68px);
  padding-bottom: 96px;
  text-align: center;
  position: relative;
}

.hero-content {
  max-width: 900px;
  margin: 0 auto;
}

.hero-title {
  font-size: 3.5rem;
  line-height: 1.18;
  font-weight: 800;
  letter-spacing: -0.035em;
  margin: 26px 0 22px;
  color: var(--text-main);
}

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

/* 品牌大标题高亮专区 */
.brand-hero-tag {
  color: var(--champagne-gold);
  font-weight: 800;
}

.hero-subtitle {
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 14px;
}

.hero-intro {
  font-size: 1.06rem;
  line-height: 1.75;
  color: var(--text-muted);
  max-width: 760px;
  margin: 0 auto 38px;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  margin-bottom: 52px;
}

/* 零丢包与专线指标信任背书 */
.hero-telemetry {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  padding: 24px 28px;
  background: var(--bg-obsidian);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  box-shadow: var(--shadow-md);
}

.telemetry-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  border-right: 1px solid var(--border-light);
  padding: 0 10px;
}

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

.telemetry-val {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--champagne-gold);
  font-variant-numeric: tabular-nums;
  line-height: 1.2;
}

.telemetry-label {
  font-size: 0.8rem;
  color: var(--text-subtle);
  margin-top: 4px;
  font-weight: 500;
}

/* 核心优势板块 (Smoked obsidian glass + razor-thin champagne-gold chamfers) */
.section-header {
  text-align: center;
  max-width: 740px;
  margin: 0 auto 58px;
}

.section-header h2 {
  font-size: 2.35rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  margin-top: 14px;
  margin-bottom: 16px;
  color: var(--text-main);
}

.section-header p {
  font-size: 1.06rem;
  color: var(--text-muted);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

/* 熏黑黑曜石卡片 + 纤细香槟金倒角 (Chamfers) + 生物荧光核心 */
.route-card {
  background: var(--bg-obsidian);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius-lg);
  padding: 38px 30px;
  position: relative;
  overflow: hidden;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-sm);
}

/* 悬停发光微交互：内部乳白色生物发光核心 + 零丢包指示器 */
.route-card::before {
  content: "";
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, var(--bioluminescent-core) 0%, transparent 60%);
  opacity: 0;
  transition: opacity 0.5s ease;
  pointer-events: none;
}

.route-card:hover {
  transform: translateY(-8px);
  border-color: var(--border-gold-hover);
  box-shadow: var(--shadow-card), 0 0 30px var(--bioluminescent-glow);
}

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

.card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
}

.card-icon-gold {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  background: rgba(212, 175, 55, 0.12);
  border: 1px solid var(--border-gold);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--champagne-gold);
}

.bioluminescent-ping {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.3);
  font-size: 0.76rem;
  font-weight: 600;
  color: var(--zero-loss-emerald);
}

.ping-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--zero-loss-emerald);
  box-shadow: 0 0 6px var(--zero-loss-emerald);
}

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

.route-card p {
  color: var(--text-muted);
  font-size: 0.96rem;
  line-height: 1.7;
  margin-bottom: 22px;
}

.card-specs-list {
  list-style: none;
  padding: 0;
  border-top: 1px solid var(--border-light);
  padding-top: 20px;
}

.card-specs-list li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.88rem;
  color: var(--text-subtle);
  margin-bottom: 10px;
}

.card-specs-list li svg {
  color: var(--champagne-gold);
  flex-shrink: 0;
}

/* 专属加速卡片 (流媒体图卡 + AI支持图卡) */
.specialty-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.specialty-card {
  background: var(--bg-obsidian);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius-lg);
  padding: 42px;
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-sm);
}

.specialty-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-gold-hover);
  box-shadow: var(--shadow-card), 0 0 25px var(--champagne-gold-glow);
}

.specialty-card::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-gold);
}

.specialty-content h3 {
  font-size: 1.65rem;
  font-weight: 700;
  margin: 16px 0 14px;
  color: var(--text-main);
}

.specialty-content p {
  color: var(--text-muted);
  font-size: 1rem;
  line-height: 1.7;
  margin-bottom: 28px;
}

.matrix-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 32px;
}

.matrix-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-tertiary);
  color: var(--text-main);
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 500;
  border: 1px solid var(--border-light);
  transition: all var(--transition-normal);
}

.matrix-chip:hover {
  border-color: var(--champagne-gold);
  color: var(--champagne-gold);
  transform: translateY(-1px);
}

/* 套餐价格对比表 (参考 Nexitally 真实网络套餐数据) */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-obsidian);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all var(--transition-normal);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

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

.pricing-card.sovereign-featured {
  border: 2px solid var(--champagne-gold);
  box-shadow: 0 12px 36px var(--champagne-gold-glow);
  transform: scale(1.02);
}

.pricing-card.sovereign-featured:hover {
  transform: scale(1.02) translateY(-8px);
}

.pricing-ribbon {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--gradient-gold);
  color: #06080f;
  padding: 5px 20px;
  border-radius: var(--radius-full);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  white-space: nowrap;
  box-shadow: 0 4px 14px var(--champagne-gold-glow);
  z-index: 2;
}

.plan-code {
  font-size: 0.82rem;
  color: var(--champagne-gold);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 700;
  margin-bottom: 4px;
}

.plan-name {
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 8px;
}

.plan-desc {
  font-size: 0.9rem;
  color: var(--text-subtle);
  margin-bottom: 24px;
}

.plan-pricing-box {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 24px;
  padding-bottom: 22px;
  border-bottom: 1px solid var(--border-light);
}

.pricing-currency {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-main);
}

.pricing-val {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1;
  color: var(--text-main);
  font-variant-numeric: tabular-nums;
}

.pricing-term {
  font-size: 0.88rem;
  color: var(--text-subtle);
}

.plan-items {
  list-style: none;
  padding: 0;
  margin-bottom: 34px;
  flex-grow: 1;
}

.plan-items li {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.94rem;
  color: var(--text-muted);
  margin-bottom: 14px;
}

.plan-items li svg {
  color: var(--champagne-gold);
  flex-shrink: 0;
}

/* 用户真实评价 */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.review-card {
  background: var(--bg-obsidian);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius-md);
  padding: 32px 26px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  transition: all var(--transition-normal);
}

.review-card:hover {
  transform: translateY(-5px);
  border-color: var(--border-gold-hover);
  box-shadow: var(--shadow-md);
}

.review-stars {
  color: var(--champagne-gold);
  margin-bottom: 14px;
  font-size: 1.1rem;
}

.review-text {
  font-size: 0.96rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 22px;
}

.review-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-top: 16px;
  border-top: 1px solid var(--border-light);
}

.avatar-gold {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-full);
  background: rgba(212, 175, 55, 0.15);
  color: var(--champagne-gold);
  border: 1px solid var(--border-gold);
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
}

.author-detail h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
}

.author-detail p {
  font-size: 0.8rem;
  color: var(--text-subtle);
}

/* 常见问题解答 (FAQ) */
.faq-box {
  max-width: 860px;
  margin: 0 auto;
}

.faq-element {
  background: var(--bg-obsidian);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius-md);
  margin-bottom: 16px;
  overflow: hidden;
  transition: all var(--transition-normal);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.faq-element:hover {
  border-color: var(--border-gold-hover);
}

.faq-trigger {
  width: 100%;
  padding: 22px 26px;
  background: transparent;
  border: none;
  font-size: 1.06rem;
  font-weight: 600;
  color: var(--text-main);
  text-align: left;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  outline: none;
  transition: color var(--transition-normal);
}

.faq-trigger:hover {
  color: var(--champagne-gold);
}

.faq-arrow {
  width: 20px;
  height: 20px;
  color: var(--champagne-gold);
  transition: transform 0.35s ease;
  flex-shrink: 0;
}

.faq-element.active .faq-arrow {
  transform: rotate(180deg);
}

.faq-content-area {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.faq-content-inner {
  padding: 0 26px 24px;
  color: var(--text-muted);
  font-size: 0.96rem;
  line-height: 1.75;
}

/* 底部 CTA 黄金横幅 */
.benthic-cta-vault {
  background: linear-gradient(135deg, rgba(212, 175, 55, 0.15) 0%, rgba(10, 13, 24, 0.95) 100%);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius-lg);
  padding: 64px 44px;
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-card);
  margin-top: 48px;
}

.benthic-cta-vault h2 {
  font-size: 2.35rem;
  font-weight: 800;
  margin-bottom: 16px;
  color: var(--text-main);
}

.benthic-cta-vault p {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 680px;
  margin: 0 auto 34px;
}

/* 规范页脚：严格只保留 4 个标题，并在新窗口打开 */
.site-footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-light);
  padding: 52px 0 38px;
  transition: background-color var(--transition-normal);
  position: relative;
  z-index: 2;
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 46px;
  margin-bottom: 30px;
  flex-wrap: wrap;
}

.footer-nav a {
  font-size: 1.02rem;
  font-weight: 600;
  color: var(--text-muted);
  position: relative;
  transition: color var(--transition-normal);
}

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

.footer-bottom {
  text-align: center;
  color: var(--text-subtle);
  font-size: 0.88rem;
  border-top: 1px dashed var(--border-light);
  padding-top: 26px;
}

.footer-bottom p {
  margin-bottom: 6px;
}

/* 子页面独立通用排版 (推荐资讯、关于我们、条款、隐私、网站地图) */
.subpage-container {
  max-width: 900px;
  margin: calc(var(--nav-height) + 44px) auto 88px;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}

.article-box {
  background: var(--bg-obsidian);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius-lg);
  padding: 50px;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: var(--shadow-card);
}

.article-header {
  border-bottom: 1px solid var(--border-light);
  padding-bottom: 26px;
  margin-bottom: 36px;
}

.article-header h1 {
  font-size: 2.3rem;
  font-weight: 800;
  margin-bottom: 12px;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.article-meta {
  color: var(--text-subtle);
  font-size: 0.92rem;
  display: flex;
  gap: 16px;
  align-items: center;
  flex-wrap: wrap;
}

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

.article-body h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-main);
  margin-top: 40px;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.article-body h2::before {
  content: "";
  display: inline-block;
  width: 4px;
  height: 22px;
  background: var(--champagne-gold);
  border-radius: 2px;
}

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

.article-body ul, .article-body ol {
  padding-left: 26px;
  margin-bottom: 22px;
}

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

.highlight-box {
  background: rgba(212, 175, 55, 0.08);
  border-left: 4px solid var(--champagne-gold);
  padding: 18px 22px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 26px 0;
  color: var(--text-main);
}

.highlight-box.warning {
  background: rgba(239, 68, 68, 0.1);
  border-left-color: #ef4444;
}

.highlight-box.success {
  background: rgba(16, 185, 129, 0.1);
  border-left-color: var(--zero-loss-emerald);
}

/* 资讯专栏卡片列表 (用于 insights.html) */
.insight-post {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius-md);
  padding: 28px;
  margin-bottom: 28px;
  transition: all var(--transition-normal);
}

.insight-post:hover {
  transform: translateY(-4px);
  border-color: var(--border-gold-hover);
  box-shadow: var(--shadow-gold);
}

.post-tag {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--champagne-gold);
  text-transform: uppercase;
  margin-bottom: 8px;
}

.insight-post h3 {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 12px;
}

.insight-post p {
  color: var(--text-muted);
  font-size: 0.96rem;
  line-height: 1.7;
  margin-bottom: 16px;
}

.post-foot {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  color: var(--text-subtle);
  border-top: 1px solid var(--border-light);
  padding-top: 14px;
}

/* 网站地图网格 */
.sitemap-list {
  list-style: none;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin-top: 16px;
  margin-bottom: 32px;
}

.sitemap-link-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius-sm);
  color: var(--text-main);
  font-weight: 600;
  transition: all var(--transition-normal);
}

.sitemap-link-card:hover {
  border-color: var(--champagne-gold);
  color: var(--champagne-gold);
  transform: translateX(5px);
}

/* ==========================================================================
   深度科普文章专用样式 (目录 TOC、正文内链、FAQ结构、相关阅读)
   ========================================================================== */

.article-breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--text-subtle);
  margin-bottom: 22px;
  flex-wrap: wrap;
}

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

.article-breadcrumb a:hover {
  color: var(--champagne-gold);
}

.article-breadcrumb span.sep {
  opacity: 0.5;
}

/* 目录 Table of Contents (TOC) */
.article-toc {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius-md);
  padding: 24px 28px;
  margin: 28px 0 36px;
  backdrop-filter: blur(8px);
}

.article-toc-title {
  font-size: 1.12rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.article-toc-title svg {
  color: var(--champagne-gold);
}

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

.article-toc-list li {
  margin-bottom: 9px;
  font-size: 0.94rem;
}

.article-toc-list li a {
  color: var(--text-muted);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: all var(--transition-normal);
}

.article-toc-list li a:hover {
  color: var(--champagne-gold);
  transform: translateX(4px);
}

/* 正文内链高亮 */
.in-text-link {
  color: var(--champagne-gold);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 4px;
  text-decoration-thickness: 1.5px;
  transition: all var(--transition-normal);
}

.in-text-link:hover {
  filter: brightness(1.2);
  text-underline-offset: 6px;
}

/* 文章正文 FAQ 结构 */
.article-faq {
  margin-top: 48px;
  padding-top: 36px;
  border-top: 1px dashed var(--border-gold);
}

.faq-qa-item {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  padding: 20px 24px;
  margin-bottom: 18px;
}

.faq-q {
  font-size: 1.08rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 10px;
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.faq-q-badge {
  background: var(--champagne-gold);
  color: #06080f;
  font-size: 0.72rem;
  font-weight: 800;
  padding: 2px 7px;
  border-radius: 4px;
  flex-shrink: 0;
  margin-top: 3px;
}

.faq-a {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.75;
  padding-left: 28px;
}

/* 文章相关阅读 (Related Articles) */
.related-reading {
  margin-top: 52px;
  padding-top: 36px;
  border-top: 1px solid var(--border-light);
}

.related-reading h3 {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 22px;
  display: flex;
  align-items: center;
  gap: 10px;
}

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

.related-card {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius-sm);
  padding: 22px;
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.related-card:hover {
  transform: translateY(-4px);
  border-color: var(--champagne-gold);
  box-shadow: var(--shadow-sm);
}

.related-card h4 {
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 10px;
  line-height: 1.5;
}

.related-card p {
  font-size: 0.88rem;
  color: var(--text-subtle);
  line-height: 1.6;
  margin-bottom: 16px;
}

.related-link-arrow {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--champagne-gold);
}

/* ==========================================================================
   响应式媒体查询 (@media) - 完美单栏触控适配
   ========================================================================== */

@media (max-width: 1024px) {
  .feature-grid,
  .pricing-grid,
  .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .pricing-card.sovereign-featured {
    transform: none;
  }
  
  .pricing-card.sovereign-featured:hover {
    transform: translateY(-8px);
  }

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

  .telemetry-item:nth-child(2) {
    border-right: none;
  }

  .hero-title {
    font-size: 2.85rem;
  }
}

@media (max-width: 768px) {
  :root {
    --nav-height: 66px;
  }

  .nav-links {
    display: none; /* 移动端精简目录，优先保证手感与性能 */
  }

  .hero-title {
    font-size: 2.25rem;
    line-height: 1.25;
  }

  .hero-subtitle {
    font-size: 1.15rem;
  }

  .hero-intro {
    font-size: 0.98rem;
    padding: 0 8px;
  }

  .hero-actions {
    flex-direction: column;
    width: 100%;
    padding: 0 10px;
  }

  .hero-actions .btn {
    width: 100%;
    min-height: 50px;
  }

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

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

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

  .feature-grid,
  .specialty-grid,
  .pricing-grid,
  .reviews-grid {
    grid-template-columns: 1fr;
    gap: 22px;
  }

  .sitemap-list,
  .related-grid {
    grid-template-columns: 1fr;
  }

  .specialty-card {
    padding: 30px 22px;
  }

  .benthic-cta-vault {
    padding: 42px 22px;
  }

  .benthic-cta-vault h2 {
    font-size: 1.8rem;
  }

  .footer-nav {
    gap: 22px;
    flex-direction: column;
    text-align: center;
  }

  .article-box {
    padding: 28px 20px;
  }

  .article-header h1 {
    font-size: 1.8rem;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 1.95rem;
  }

  .section {
    padding: 60px 0;
  }

  .pricing-val {
    font-size: 2.4rem;
  }

  .pricing-ribbon {
    font-size: 0.72rem;
    padding: 4px 14px;
    letter-spacing: 0.02em;
    white-space: nowrap;
  }
}