/* ==========================================================================
   飞鸟云 (feiniaonyun.mom) - 航空飞行气动美学样式系统
   Stratospheric Aviation & Kinetic Flight Aesthetic
   纯原生 CSS3 · 零第三方框架 · 极致秒开 · 60fps 动效 · 优化垂直居中与紧凑布局
   ========================================================================== */

/* --- 1. 颜色与气动设计系统变量 (白天模式 - 默认) --- */
:root {
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;

  /* 航空气动主色谱 (Aerodynamic Palette) */
  --color-sky-blue: #0284c7;        /* 电子天际蓝 (Electric Sky Blue) */
  --color-sky-hover: #0369a1;
  --color-jetstream: #0284c7;       /* 白天模式强调蓝 */
  --color-jetstream-glow: rgba(2, 132, 199, 0.18);
  --color-aero-cyan: #0284c7;
  --color-radar-green: #059669;      /* 雷达信标绿 */
  --color-radar-pulse: rgba(5, 150, 105, 0.25);

  /* 背景与表面 (高空平流层纯净晴空白) */
  --bg-page: #f0f7ff;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #f8fafc;
  --bg-card: rgba(255, 255, 255, 0.88);
  --bg-card-hover: #ffffff;
  --bg-nav: rgba(240, 247, 255, 0.92);
  --bg-badge: rgba(2, 132, 199, 0.1);
  --bg-radar-box: rgba(255, 255, 255, 0.95);

  /* 文本色 (高对比度深海航天蓝黑与气动银灰) */
  --text-main: #0a1128;
  --text-secondary: #334155;
  --text-muted: #64748b;
  --text-inverse: #ffffff;
  --text-badge: #0284c7;
  --text-mach: #0284c7;

  /* 边框与微光 */
  --border-light: rgba(186, 230, 253, 0.7);
  --border-card: #e2e8f0;
  --border-focus: #0284c7;
  --border-radar: rgba(2, 132, 199, 0.25);

  /* 气动阴影体系 */
  --shadow-sm: 0 1px 3px rgba(10, 17, 40, 0.05);
  --shadow-md: 0 4px 20px -2px rgba(2, 132, 199, 0.08), 0 2px 6px -1px rgba(10, 17, 40, 0.04);
  --shadow-lg: 0 12px 36px -4px rgba(2, 132, 199, 0.12), 0 4px 12px -2px rgba(10, 17, 40, 0.06);
  --shadow-hover: 0 20px 48px -8px rgba(2, 132, 199, 0.2);

  /* 气动平流层渐变 */
  --grad-primary: linear-gradient(135deg, #0284c7 0%, #0369a1 50%, #075985 100%);
  --grad-jetstream: linear-gradient(135deg, #0284c7 0%, #38bdf8 100%);
  --grad-badge: linear-gradient(135deg, rgba(2, 132, 199, 0.12) 0%, rgba(56, 189, 248, 0.18) 100%);

  /* 磨砂气动玻璃 */
  --glass-bg: rgba(255, 255, 255, 0.85);
  --glass-border: rgba(186, 230, 253, 0.6);
  --glass-blur: blur(14px);

  /* 布局与圆角 */
  --container-max: 1220px;
  --radius-xs: 6px;
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;

  /* 动效过渡 */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-theme: background-color 0.35s ease, color 0.35s ease, border-color 0.35s ease, box-shadow 0.35s ease;
}

/* --- 2. 气动夜航模式 (Aerospace Midnight - 暗色主题) --- */
[data-theme="dark"] {
  --bg-page: #0a1128;
  --bg-surface: #0f1738;
  --bg-surface-elevated: #15224d;
  --bg-card: rgba(15, 23, 56, 0.78);
  --bg-card-hover: rgba(21, 34, 77, 0.88);
  --bg-nav: rgba(10, 17, 40, 0.88);
  --bg-badge: rgba(56, 189, 248, 0.14);
  --bg-radar-box: rgba(15, 23, 56, 0.88);

  --color-sky-blue: #38bdf8;
  --color-sky-hover: #7dd3fc;
  --color-jetstream: #38bdf8;
  --color-jetstream-glow: rgba(56, 189, 248, 0.28);
  --color-aero-cyan: #00f0ff;
  --color-radar-green: #10b981;
  --color-radar-pulse: rgba(16, 185, 129, 0.4);

  --text-main: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --text-inverse: #0a1128;
  --text-badge: #38bdf8;
  --text-mach: #00f0ff;

  --border-light: rgba(56, 189, 248, 0.2);
  --border-card: rgba(56, 189, 248, 0.14);
  --border-focus: #38bdf8;
  --border-radar: rgba(56, 189, 248, 0.3);

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.5);
  --shadow-md: 0 4px 24px -2px rgba(0, 0, 0, 0.6), 0 2px 8px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 12px 40px -4px rgba(0, 0, 0, 0.75), 0 0 30px rgba(56, 189, 248, 0.12);
  --shadow-hover: 0 20px 48px -6px rgba(0, 0, 0, 0.85), 0 0 36px rgba(56, 189, 248, 0.24);

  --glass-bg: rgba(15, 23, 56, 0.8);
  --glass-border: rgba(56, 189, 248, 0.22);

  --grad-primary: linear-gradient(135deg, #0284c7 0%, #38bdf8 100%);
  --grad-jetstream: linear-gradient(135deg, #38bdf8 0%, #00f0ff 100%);
  --grad-badge: linear-gradient(135deg, rgba(56, 189, 248, 0.15) 0%, rgba(0, 240, 255, 0.2) 100%);
}

/* --- 3. 基础重置与排版 --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-page);
  color: var(--text-main);
  line-height: 1.6;
  min-height: 100vh;
  transition: var(--transition-theme);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

img, svg {
  vertical-align: middle;
}

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

/* --- 4. 容器与通用排版 (优化垂直居中与紧凑外边距) --- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.section {
  padding: 3.5rem 0;
  position: relative;
}

/* 套餐价格专区紧凑排版，避免底部截断 */
#pricing.section {
  padding: 2.25rem 0 3.25rem 0;
}

.section-alt {
  background-color: var(--bg-surface);
  transition: background-color 0.35s ease;
}

.section-header {
  text-align: center;
  max-width: 860px;
  margin: 0 auto 2rem;
}

/* 航空气动信标标签 (Aero Beacon Tag) */
.badge-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.3rem 0.85rem;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-jetstream);
  background: var(--bg-badge);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-full);
  margin-bottom: 0.65rem;
  box-shadow: 0 2px 10px var(--color-jetstream-glow);
}

.badge-tag svg {
  width: 13px;
  height: 13px;
}

.section-title {
  font-size: 2.15rem;
  font-weight: 800;
  line-height: 1.25;
  color: var(--text-main);
  margin-bottom: 0.65rem;
  letter-spacing: -0.025em;
  text-wrap: balance;
}

.section-desc {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.65;
  max-width: 820px;
  margin-left: auto;
  margin-right: auto;
  text-wrap: balance;
}

/* 喷气流文字渐变 */
.text-jetstream {
  background: var(--grad-jetstream);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
  font-weight: 900;
}

/* --- 5. 顶部飞行控制导航栏 (Aero Header & Nav) --- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--bg-nav);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--border-light);
  transition: var(--transition-theme);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.75rem;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.015em;
}

.brand-icon {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 12px;
  background: var(--grad-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  box-shadow: 0 4px 16px var(--color-jetstream-glow);
  position: relative;
  overflow: hidden;
}

.brand-icon svg {
  width: 1.5rem;
  height: 1.5rem;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.75rem;
  list-style: none;
}

.nav-link {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-secondary);
  position: relative;
  padding: 0.35rem 0;
  transition: color var(--transition-fast);
}

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

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

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

.nav-link-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.15rem 0.45rem;
  background: var(--bg-badge);
  color: var(--color-jetstream);
  border-radius: var(--radius-full);
  margin-left: 0.25rem;
  vertical-align: middle;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* 精致专业半透明昼夜切换按钮 */
.theme-toggle-btn {
  width: 2.6rem;
  height: 2.6rem;
  border-radius: var(--radius-full);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-light);
  color: var(--text-main);
  transition: all var(--transition-normal);
  cursor: pointer;
  position: relative;
  box-shadow: var(--shadow-sm);
}

.theme-toggle-btn:hover {
  border-color: var(--color-jetstream);
  box-shadow: 0 0 16px var(--color-jetstream-glow);
  transform: translateY(-2px);
}

.theme-icon {
  width: 1.3rem;
  height: 1.3rem;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.2s ease;
}

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

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

/* 移动端菜单按钮 */
.mobile-menu-btn {
  display: none;
  width: 2.6rem;
  height: 2.6rem;
  align-items: center;
  justify-content: center;
  background: var(--glass-bg);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  color: var(--text-main);
  cursor: pointer;
}

/* --- 6. 按钮设计规范 --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-size: 0.9375rem;
  font-weight: 700;
  padding: 0.7rem 1.5rem;
  border-radius: var(--radius-full);
  transition: all var(--transition-normal);
  text-decoration: none;
  cursor: pointer;
  white-space: nowrap;
  line-height: 1.2;
}

.btn-primary {
  background: var(--grad-primary);
  color: #ffffff !important;
  box-shadow: 0 4px 18px var(--color-jetstream-glow);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 26px var(--color-jetstream-glow);
  opacity: 0.95;
}

.btn-secondary {
  background: var(--glass-bg);
  color: var(--text-main);
  border: 1px solid var(--border-light);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  background: var(--bg-surface-elevated);
  border-color: var(--color-jetstream);
  color: var(--color-jetstream);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn-lg {
  padding: 0.85rem 1.85rem;
  font-size: 1.025rem;
}

.btn-block {
  width: 100%;
}

.btn-white {
  background: #ffffff;
  color: #0284c7 !important;
  font-weight: 800;
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

.btn-white:hover {
  background: #f8fafc;
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.25);
}

/* --- 7. 主视觉区 (Aerospace Hero Section - 紧凑居中) --- */
.hero-section {
  padding-top: 6.75rem;
  padding-bottom: 3.5rem;
  position: relative;
  overflow: hidden;
  text-align: center;
}

.hero-canvas-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
  opacity: 0.75;
}

.hero-glow-radial {
  position: absolute;
  top: -120px;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 520px;
  background: radial-gradient(circle, var(--color-jetstream-glow) 0%, rgba(2, 132, 199, 0) 70%);
  pointer-events: none;
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 960px;
  margin: 0 auto;
}

.hero-headline {
  font-size: 3.1rem;
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -0.035em;
  margin-bottom: 1.15rem;
  text-wrap: balance;
}

.hero-subhead {
  font-size: 1.15rem;
  color: var(--text-secondary);
  line-height: 1.7;
  max-width: 820px;
  margin: 0 auto 2rem;
  text-wrap: balance;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  margin-bottom: 2.75rem;
  flex-wrap: wrap;
}

/* --- 8. 实时航空雷达扫描仪表盘 --- */
.radar-panel-wrap {
  margin: 1.75rem auto 2.5rem;
  max-width: 900px;
  background: var(--bg-radar-box);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-radar);
  border-radius: var(--radius-lg);
  padding: 1.5rem 1.75rem;
  box-shadow: var(--shadow-lg);
  position: relative;
  overflow: hidden;
}

.radar-panel-wrap::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(56, 189, 248, 0.12), transparent);
  animation: radar-sweep 4s linear infinite;
  pointer-events: none;
}

@keyframes radar-sweep {
  0% { left: -100%; }
  100% { left: 100%; }
}

.radar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.25rem;
  padding-bottom: 0.85rem;
  border-bottom: 1px solid var(--border-light);
  flex-wrap: wrap;
  gap: 0.75rem;
}

.radar-title-group {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.radar-blip-pulse {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-radar-green);
  box-shadow: 0 0 10px var(--color-radar-green);
  animation: radar-pulse 2s infinite;
}

@keyframes radar-pulse {
  0% { box-shadow: 0 0 0 0 var(--color-radar-pulse); }
  70% { box-shadow: 0 0 0 10px transparent; }
  100% { box-shadow: 0 0 0 0 transparent; }
}

.radar-title {
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-main);
}

.radar-frequency-badge {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--color-jetstream);
  background: var(--bg-badge);
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-xs);
  border: 1px solid var(--border-light);
}

.radar-nodes-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
}

.radar-node-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 0.85rem 1.15rem;
  text-align: left;
  transition: all var(--transition-normal);
  position: relative;
}

.radar-node-card:hover {
  border-color: var(--color-jetstream);
  transform: translateY(-3px);
  box-shadow: 0 6px 18px var(--color-jetstream-glow);
}

.node-meta-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.35rem;
}

.node-code {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

.node-status-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--color-radar-green);
}

.node-city {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.25rem;
}

.node-ping-val {
  font-family: var(--font-mono);
  font-size: 1.3rem;
  font-weight: 900;
  color: var(--text-mach);
  line-height: 1;
}

.node-ping-unit {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-left: 2px;
}

/* --- 9. "Zero-Drag" 零阻力协议巡航切换器 --- */
.protocol-switcher-wrap {
  margin: 2.5rem auto 1rem;
  max-width: 900px;
  background: var(--bg-surface);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow-md);
  text-align: left;
}

.protocol-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.25rem;
  flex-wrap: wrap;
  gap: 1rem;
}

.protocol-title {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.protocol-nav-tabs {
  display: flex;
  background: var(--bg-page);
  padding: 0.3rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-light);
  gap: 0.3rem;
}

.protocol-tab-btn {
  padding: 0.4rem 1.1rem;
  font-size: 0.85rem;
  font-weight: 700;
  border-radius: var(--radius-full);
  color: var(--text-secondary);
  transition: all var(--transition-fast);
  cursor: pointer;
}

.protocol-tab-btn.active {
  background: var(--color-jetstream);
  color: #ffffff;
  box-shadow: 0 2px 10px var(--color-jetstream-glow);
}

.protocol-display-box {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: 1.35rem 1.5rem;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 1.25rem;
  align-items: center;
}

.proto-info-title {
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 0.25rem;
}

.proto-info-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.55;
}

.proto-stat-block {
  border-left: 1px solid var(--border-light);
  padding-left: 1.15rem;
}

.proto-stat-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.2rem;
}

.proto-stat-value {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--text-mach);
}

/* 全平台流线型客户端底座 */
.client-dock {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  margin-top: 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-light);
  flex-wrap: wrap;
}

.client-dock-label {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.client-dock-items {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.dock-item {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  padding: 0.35rem 0.8rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.dock-item:hover {
  border-color: var(--color-jetstream);
  color: var(--color-jetstream);
  transform: translateY(-2px);
}

.dock-item svg {
  width: 1.15rem;
  height: 1.15rem;
}

/* --- 10. 3大核心优势卡片 --- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
  max-width: 1180px;
  margin: 0 auto;
  justify-content: center;
}

.feature-card {
  background: var(--bg-card);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 2.25rem 1.85rem;
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}

.feature-card:hover {
  transform: translateY(-6px);
  border-color: var(--color-jetstream);
  box-shadow: var(--shadow-hover);
  background: var(--bg-card-hover);
}

.feature-velocity-badge {
  position: absolute;
  top: 1.25rem;
  right: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 800;
  color: var(--text-mach);
  background: var(--bg-badge);
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-xs);
  border: 1px solid var(--border-light);
}

.feature-icon-wrapper {
  width: 3.25rem;
  height: 3.25rem;
  border-radius: var(--radius-md);
  background: var(--bg-badge);
  color: var(--color-jetstream);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.35rem;
  border: 1px solid var(--border-light);
  transition: all var(--transition-normal);
}

.feature-card:hover .feature-icon-wrapper {
  background: var(--grad-primary);
  color: #fff;
  transform: scale(1.08);
}

.feature-icon-wrapper svg {
  width: 1.75rem;
  height: 1.75rem;
}

.feature-title {
  font-size: 1.3rem;
  font-weight: 800;
  margin-bottom: 0.65rem;
  color: var(--text-main);
  letter-spacing: -0.015em;
}

.feature-desc {
  font-size: 0.925rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 1.25rem;
}

.feature-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: auto;
}

.tag-pill {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.22rem 0.65rem;
  border-radius: var(--radius-sm);
  background: var(--bg-badge);
  color: var(--color-jetstream);
  border: 1px solid var(--border-light);
}

/* --- 11. 4K/8K 流媒体图卡 & AI 支持图卡 --- */
.showcase-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.75rem;
  max-width: 1180px;
  margin: 0 auto;
}

.showcase-card {
  background: var(--bg-card);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 2.25rem 2rem;
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-normal);
}

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

.showcase-card-header {
  display: flex;
  align-items: flex-start;
  gap: 1.15rem;
  margin-bottom: 1.25rem;
}

.showcase-icon-badge {
  width: 3.25rem;
  height: 3.25rem;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.showcase-media .showcase-icon-badge {
  background: linear-gradient(135deg, #e11d48 0%, #be123c 100%);
  color: #fff;
  box-shadow: 0 4px 18px rgba(225, 29, 72, 0.3);
}

.showcase-ai .showcase-icon-badge {
  background: linear-gradient(135deg, #0284c7 0%, #0369a1 100%);
  color: #fff;
  box-shadow: 0 4px 18px rgba(2, 132, 199, 0.3);
}

.showcase-icon-badge svg {
  width: 1.75rem;
  height: 1.75rem;
}

.showcase-card-title {
  font-size: 1.35rem;
  font-weight: 800;
  margin-bottom: 0.25rem;
  color: var(--text-main);
}

.showcase-card-subtitle {
  font-size: 0.88rem;
  color: var(--text-secondary);
}

.showcase-desc {
  font-size: 0.925rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 1.5rem;
}

.brand-chips-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
  margin-top: auto;
}

.brand-chip {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-light);
  padding: 0.75rem 1rem;
  border-radius: var(--radius-md);
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--text-main);
  transition: all var(--transition-fast);
}

.brand-chip:hover {
  border-color: var(--color-jetstream);
  background: var(--bg-badge);
  transform: translateX(4px);
}

.chip-status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-radar-green);
  box-shadow: 0 0 10px var(--color-radar-green);
  flex-shrink: 0;
}

/* --- 12. 真实套餐价格对比表 (优化垂直紧凑与居中，彻底杜绝按钮截断) --- */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  max-width: 1160px;
  margin: 0 auto;
  align-items: stretch;
  justify-content: center;
}

.pricing-card {
  background: var(--bg-card);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 1.85rem 1.65rem;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all var(--transition-normal);
}

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

.pricing-card.featured {
  border: 2px solid var(--color-sky-blue);
  background: var(--bg-card-hover);
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

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

.pricing-badge {
  position: absolute;
  top: -0.85rem;
  right: 1.5rem;
  background: var(--grad-primary);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 800;
  padding: 0.3rem 0.85rem;
  border-radius: var(--radius-full);
  box-shadow: 0 4px 14px var(--color-jetstream-glow);
  letter-spacing: 0.03em;
}

.plan-name {
  font-size: 1.35rem;
  font-weight: 900;
  color: var(--text-main);
  margin-bottom: 0.35rem;
}

.plan-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 1.15rem;
  min-height: 2.4rem;
  line-height: 1.45;
}

.plan-price-wrap {
  display: flex;
  align-items: baseline;
  gap: 0.25rem;
  margin-bottom: 1.15rem;
  padding-bottom: 1.15rem;
  border-bottom: 1px solid var(--border-light);
}

.price-currency {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--color-jetstream);
}

.price-amount {
  font-size: 2.75rem;
  font-weight: 900;
  line-height: 1;
  color: var(--text-main);
}

.price-period {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
}

.plan-features-list {
  list-style: none;
  margin-bottom: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  flex-grow: 1;
}

.plan-feature-item {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-size: 0.885rem;
  color: var(--text-secondary);
}

.plan-feature-item svg {
  color: var(--color-radar-green);
  width: 1.15rem;
  height: 1.15rem;
  flex-shrink: 0;
}

.plan-feature-item.muted {
  color: var(--text-muted);
}

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

.pricing-card .btn {
  padding: 0.65rem 1.25rem;
  font-size: 0.925rem;
}

/* --- 13. 用户口碑与飞行评价 --- */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
  max-width: 1180px;
  margin: 0 auto;
}

.testimonial-card {
  background: var(--bg-card);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 1.85rem 1.65rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all var(--transition-normal);
}

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

.rating-stars {
  display: flex;
  gap: 0.25rem;
  color: #f59e0b;
  margin-bottom: 1rem;
}

.rating-stars svg {
  width: 1.1rem;
  height: 1.1rem;
}

.testimonial-text {
  font-size: 0.925rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 1.35rem;
}

.testimonial-user {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.user-avatar {
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 50%;
  background: var(--bg-badge);
  border: 1px solid var(--border-light);
  color: var(--color-jetstream);
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  flex-shrink: 0;
}

.user-meta-name {
  font-size: 0.925rem;
  font-weight: 800;
  color: var(--text-main);
}

.user-meta-role {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* --- 14. 常见问题 (FAQ 手风琴) --- */
.faq-wrap {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

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

.faq-item.active {
  border-color: var(--color-jetstream);
  box-shadow: var(--shadow-sm);
}

.faq-question {
  width: 100%;
  padding: 1.25rem 1.65rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  text-align: left;
  font-size: 1.025rem;
  font-weight: 700;
  color: var(--text-main);
  background: none;
  border: none;
  cursor: pointer;
  gap: 1rem;
}

.faq-question:hover {
  color: var(--color-jetstream);
}

.faq-toggle-icon {
  width: 1.25rem;
  height: 1.25rem;
  transition: transform 0.25s ease;
  color: var(--text-muted);
  flex-shrink: 0;
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
  padding: 0 1.65rem;
  color: var(--text-secondary);
  font-size: 0.925rem;
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  max-height: 350px;
  padding: 0 1.65rem 1.25rem;
}

/* --- 15. 底部极速转化横幅 --- */
.bottom-cta-box {
  background: var(--grad-primary);
  border-radius: var(--radius-lg);
  padding: 3.25rem 2.25rem;
  text-align: center;
  color: #fff;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.bottom-cta-title {
  font-size: 2.15rem;
  font-weight: 900;
  margin-bottom: 0.85rem;
  color: #fff;
}

.bottom-cta-desc {
  font-size: 1.05rem;
  color: rgba(255, 255, 255, 0.92);
  max-width: 650px;
  margin: 0 auto 2rem;
  text-wrap: balance;
}

/* --- 16. 精简专业页脚 (严格只保留4个标题，且新页面展示) --- */
.site-footer {
  background: var(--bg-surface);
  border-top: 1px solid var(--border-light);
  padding: 3rem 0 2rem;
  transition: var(--transition-theme);
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 3rem;
  list-style: none;
  margin-bottom: 1.75rem;
  flex-wrap: wrap;
}

.footer-link {
  font-size: 1.025rem;
  font-weight: 700;
  color: var(--text-secondary);
  transition: color var(--transition-fast);
  padding: 0.4rem 0.75rem;
}

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

.footer-bottom {
  text-align: center;
  padding-top: 1.75rem;
  border-top: 1px solid var(--border-light);
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* --- 17. 独立内页与推荐资讯文章卡片样式 --- */
.page-hero {
  padding-top: 7rem;
  padding-bottom: 2.75rem;
  text-align: center;
  border-bottom: 1px solid var(--border-light);
}

.content-article {
  max-width: 860px;
  margin: 2.75rem auto 4rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-lg);
  padding: 3rem;
  box-shadow: var(--shadow-sm);
}

.content-article h2 {
  font-size: 1.55rem;
  font-weight: 800;
  margin: 2.25rem 0 0.85rem;
  color: var(--text-main);
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-light);
}

.content-article h2:first-of-type {
  margin-top: 0;
}

.content-article h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 1.5rem 0 0.75rem;
  color: var(--text-main);
}

.content-article p {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 1.25rem;
}

.content-article ul, .content-article ol {
  margin: 1rem 0 1.5rem 1.75rem;
  color: var(--text-secondary);
  line-height: 1.8;
}

.content-article li {
  margin-bottom: 0.5rem;
}

.notice-box {
  background: var(--bg-badge);
  border-left: 4px solid var(--color-jetstream);
  padding: 1.25rem 1.5rem;
  border-radius: var(--radius-sm);
  margin: 1.75rem 0;
  color: var(--text-main);
}

/* 资讯列表网格 */
.insights-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.75rem;
  margin: 2rem 0;
}

.insight-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-normal);
}

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

.insight-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.insight-tag {
  font-weight: 700;
  color: var(--color-jetstream);
  background: var(--bg-badge);
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-xs);
}

.insight-title {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 0.65rem;
  line-height: 1.4;
}

.insight-summary {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 1.35rem;
  flex-grow: 1;
}

.insight-read-link {
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--color-jetstream);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.insight-read-link:hover {
  gap: 0.65rem;
}

/* --- 18. 移动端与全平台响应式 (@media) --- */
@media (max-width: 1024px) {
  .features-grid,
  .pricing-grid,
  .testimonials-grid,
  .radar-nodes-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .protocol-display-box {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .section {
    padding: 3rem 0;
  }

  #pricing.section {
    padding: 2.5rem 0;
  }

  .hero-section {
    padding-top: 6rem;
    padding-bottom: 3rem;
  }

  .hero-headline {
    font-size: 2.25rem;
  }

  .hero-subhead {
    font-size: 1rem;
  }

  .features-grid,
  .showcase-grid,
  .pricing-grid,
  .testimonials-grid,
  .radar-nodes-grid,
  .insights-grid {
    grid-template-columns: 1fr;
  }

  .brand-chips-grid {
    grid-template-columns: 1fr;
  }

  .protocol-display-box {
    grid-template-columns: 1fr;
  }

  .proto-stat-block {
    border-left: none;
    border-top: 1px solid var(--border-light);
    padding-left: 0;
    padding-top: 0.75rem;
  }

  .mobile-menu-btn {
    display: inline-flex;
  }

  .nav-links {
    position: fixed;
    top: 4.75rem;
    left: 0;
    right: 0;
    background: var(--bg-surface);
    border-bottom: 1px solid var(--border-light);
    flex-direction: column;
    padding: 1.5rem;
    gap: 1.25rem;
    display: none;
    box-shadow: var(--shadow-lg);
  }

  .nav-links.open {
    display: flex;
  }

  .footer-nav {
    flex-direction: column;
    gap: 1rem;
  }

  .content-article {
    padding: 2rem 1.5rem;
    margin: 2rem auto;
  }

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

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

  .btn {
    min-height: 48px;
  }
}

@media (max-width: 480px) {
  .hero-headline {
    font-size: 1.85rem;
  }

  .section-title {
    font-size: 1.65rem;
  }
}

/* --- 19. 长篇深度 SEO 文章专属样式 --- */
.breadcrumb-nav {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

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

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

.breadcrumb-separator {
  color: var(--text-muted);
  font-size: 0.75rem;
}

.article-header {
  margin-bottom: 2.5rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border-light);
}

.article-meta-bar {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-top: 1rem;
  flex-wrap: wrap;
}

.article-meta-item {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

/* 目录 (Table of Contents - TOC) */
.toc-box {
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-left: 4px solid var(--color-sky-blue);
  border-radius: var(--radius-md);
  padding: 1.5rem 1.75rem;
  margin: 2rem 0 2.5rem;
  box-shadow: var(--shadow-sm);
}

.toc-title {
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 0.85rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.toc-list {
  list-style: none;
  margin: 0 !important;
  padding: 0 !important;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.toc-list li {
  margin: 0 !important;
  font-size: 0.925rem;
}

.toc-list a {
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: all var(--transition-fast);
}

.toc-list a:hover {
  color: var(--color-sky-blue);
  transform: translateX(4px);
}

.toc-num {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-sky-blue);
}

/* 数据对比表格 */
.table-responsive {
  width: 100%;
  overflow-x: auto;
  margin: 1.75rem 0;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-card);
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.925rem;
}

.data-table th,
.data-table td {
  padding: 0.85rem 1.15rem;
  border-bottom: 1px solid var(--border-light);
}

.data-table th {
  background: var(--bg-surface-elevated);
  font-weight: 800;
  color: var(--text-main);
  white-space: nowrap;
}

.data-table tr:hover td {
  background: var(--bg-badge);
}

/* 内链与锚文本 */
.internal-link {
  color: var(--color-sky-blue);
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color var(--transition-fast);
}

.internal-link:hover {
  color: var(--color-sky-hover);
}

/* 相关阅读区域 */
.related-reading-box {
  margin-top: 3.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-light);
}

.related-reading-title {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}

.related-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
}

.related-card:hover {
  border-color: var(--color-sky-blue);
  transform: translateY(-3px);
  box-shadow: var(--shadow-sm);
}

.related-card-tag {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-sky-blue);
  margin-bottom: 0.4rem;
}

.related-card-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.45;
}

@media (max-width: 768px) {
  .related-grid {
    grid-template-columns: 1fr;
  }
}