/* ===================================================================
   悠兔机场 (Youtuu Cloud) - 平流层极简冰滑设计系统
   Stratospheric Frictionless-Glide UI Design System
   纯原生 CSS · 冰晶高空白色调 · 铅笔石墨灰 · 苍穹天蓝微语 · 零AI浮躁光斑
   =================================================================== */

:root {
  /* 基础字体族 */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  /* 调色板：冰晶纯粹平流层 (默认白天模式) */
  --ice-white: #f8fafc;              /* 高空纯净冰白底色 */
  --surface-pure: #ffffff;           /* 悬浮微层白 */
  --surface-glass: rgba(255, 255, 255, 0.78);
  --surface-subtle: #f1f5f9;         /* 低阻微浅灰 */
  
  /* 建筑铅笔石墨体系 (Architectural Pencil Graphite) */
  --graphite-900: #0f172a;           /* 最深文字 */
  --graphite-700: #334155;           /* 建筑铅笔石墨主色 */
  --graphite-500: #64748b;           /* 副标题与说明 */
  --graphite-300: #cbd5e1;           /* 极细参考线 */
  --graphite-200: #e2e8f0;           /* 平流层无阻边框线 */

  /* 苍穹天蓝微语 (Tranquil Whisper of Sky Blue) */
  --sky-blue: #38bdf8;               /* 苍穹天蓝核心 */
  --sky-blue-deep: #0284c7;          /* 悬浮深海蓝 */
  --sky-blue-soft: rgba(56, 189, 248, 0.12); /* 天蓝呼吸晕染 */
  --sky-blue-border: rgba(56, 189, 248, 0.28);
  
  --emerald-telemetry: #10b981;      /* 毫秒低延时状态绿 */

  /* 动态交互与模拟微回弹 */
  --transition-glide: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-recoil: transform 0.15s cubic-bezier(0.34, 1.56, 0.64, 1);
  --transition-theme: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;

  /* 极简无阻阴影体系 */
  --shadow-frictionless: 0 4px 20px -2px rgba(15, 23, 42, 0.04), 0 1px 3px rgba(15, 23, 42, 0.02);
  --shadow-floating: 0 16px 40px -8px rgba(15, 23, 42, 0.07), 0 0 0 1px rgba(226, 232, 240, 0.8);
  --shadow-sky: 0 10px 30px -4px rgba(56, 189, 248, 0.18);

  /* 主题按钮 */
  --theme-btn-bg: rgba(255, 255, 255, 0.85);
  --theme-btn-border: var(--graphite-200);
}

/* 深邃平流层黑夜模式 */
[data-theme="dark"] {
  --ice-white: #0a0f18;              /* 深空平流层黑 */
  --surface-pure: #111827;           /* 深色漂浮容器 */
  --surface-glass: rgba(17, 24, 39, 0.82);
  --surface-subtle: #172033;         /* 微深石墨底色 */

  --graphite-900: #f8fafc;           /* 逆光冰白主文字 */
  --graphite-700: #cbd5e1;           /* 浅铅笔石墨色 */
  --graphite-500: #94a3b8;           /* 柔和说明文案 */
  --graphite-300: #334155;           /* 深色参考线 */
  --graphite-200: #1e293b;           /* 深空分割边框 */

  --sky-blue: #38bdf8;
  --sky-blue-deep: #7dd3fc;
  --sky-blue-soft: rgba(56, 189, 248, 0.16);
  --sky-blue-border: rgba(56, 189, 248, 0.35);

  --shadow-frictionless: 0 4px 20px -2px rgba(0, 0, 0, 0.35);
  --shadow-floating: 0 16px 40px -8px rgba(0, 0, 0, 0.55), 0 0 0 1px rgba(51, 65, 85, 0.5);
  --shadow-sky: 0 10px 30px -4px rgba(56, 189, 248, 0.25);

  --theme-btn-bg: rgba(30, 41, 59, 0.7);
  --theme-btn-border: #334155;
}

/* 全局重置与平滑滚动基准 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.65;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--ice-white);
  color: var(--graphite-700);
  transition: var(--transition-theme);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.2s ease, opacity 0.2s ease;
}

img, svg {
  display: block;
  max-width: 100%;
}

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

/* 锚点滚动吸顶偏移修正 */
section[id], div[id] {
  scroll-margin-top: 5.5rem;
}

/* 布局容器 */
.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 1.75rem;
}

.section {
  padding: 6rem 0;
  position: relative;
}

.section-title-wrap {
  text-align: center;
  max-width: 780px;
  margin: 0 auto 3.75rem auto;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.3rem 0.85rem;
  background: var(--sky-blue-soft);
  color: var(--sky-blue-deep);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border-radius: 9999px;
  border: 1px solid var(--sky-blue-border);
  margin-bottom: 0.85rem;
}

[data-theme="dark"] .section-tag {
  color: var(--sky-blue);
}

.section-title {
  font-size: 2.35rem;
  font-weight: 800;
  line-height: 1.25;
  color: var(--graphite-900);
  margin-bottom: 1rem;
  letter-spacing: -0.025em;
}

.section-desc {
  font-size: 1.075rem;
  color: var(--graphite-500);
  line-height: 1.75;
}

/* ===================================================================
   页眉导航 (包含首页 + 全部板块锚点 + 推荐资讯)
   =================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--surface-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--graphite-200);
  transition: var(--transition-theme);
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--graphite-900);
  letter-spacing: -0.02em;
}

.brand-logo-img {
  height: 2.35rem;
  width: auto;
  max-width: 3.2rem;
  display: block;
  object-fit: contain;
  transition: transform 0.25s ease, filter var(--transition-theme);
}

.brand:hover .brand-logo-img {
  transform: translateY(-1px) scale(1.06);
}

[data-theme="dark"] .brand-logo-img {
  filter: brightness(0) invert(1);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 1.35rem;
  list-style: none;
}

.nav-link {
  font-size: 0.925rem;
  font-weight: 500;
  color: var(--graphite-500);
  padding: 0.35rem 0.6rem;
  border-radius: 0.4rem;
  position: relative;
  transition: color 0.2s ease;
}

.nav-link:hover {
  color: var(--graphite-900);
}

/* 推荐资讯特殊高亮样式 */
.nav-link.nav-link-news {
  color: var(--sky-blue-deep);
  font-weight: 600;
  background: var(--sky-blue-soft);
  border: 1px solid var(--sky-blue-border);
  padding: 0.3rem 0.75rem;
  border-radius: 9999px;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

[data-theme="dark"] .nav-link.nav-link-news {
  color: var(--sky-blue);
}

.nav-link.nav-link-news:hover {
  background: rgba(56, 189, 248, 0.2);
  transform: translateY(-1px);
}

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

/* 昼夜模式切换按钮：精致半透明无粗糙Emoji */
.theme-toggle-btn {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  background: var(--theme-btn-bg);
  border: 1px solid var(--theme-btn-border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--graphite-700);
  transition: all 0.2s ease;
  outline: none;
}

.theme-toggle-btn:hover {
  color: var(--graphite-900);
  border-color: var(--sky-blue);
  transform: translateY(-1px);
}

.theme-toggle-btn svg {
  width: 1.2rem;
  height: 1.2rem;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

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

/* 头部注册快捷按钮 */
.btn-header-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.55rem 1.2rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: #ffffff;
  background: var(--graphite-900);
  border-radius: 0.6rem;
  border: 1px solid var(--graphite-700);
  transition: var(--transition-recoil), box-shadow 0.2s ease;
  box-shadow: var(--shadow-frictionless);
}

.btn-header-cta:hover {
  background: #000000;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.15);
  color: #ffffff;
}

[data-theme="dark"] .btn-header-cta {
  background: var(--sky-blue);
  color: #0b1120;
  border-color: var(--sky-blue);
  font-weight: 700;
}

[data-theme="dark"] .btn-header-cta:hover {
  background: #7dd3fc;
  box-shadow: 0 4px 16px rgba(56, 189, 248, 0.35);
  color: #0b1120;
}

.btn-header-cta:active {
  transform: translateY(1px) scale(0.97);
}

/* ===================================================================
   主视觉区 (Hero Section) - 冰滑平流层与微回弹触感
   =================================================================== */
.hero-section {
  padding: 6.5rem 0 4.5rem 0;
  text-align: center;
  position: relative;
  background: radial-gradient(100% 60% at 50% 10%, var(--sky-blue-soft) 0%, transparent 80%);
}

.hero-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.35rem 1rem;
  background: var(--surface-pure);
  border: 1px solid var(--graphite-200);
  border-radius: 9999px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--graphite-700);
  margin-bottom: 2rem;
  box-shadow: var(--shadow-frictionless);
}

.hero-pill-status-dot {
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 50%;
  background: var(--emerald-telemetry);
  box-shadow: 0 0 8px var(--emerald-telemetry);
  animation: pulse-telemetry 2.5s infinite;
}

@keyframes pulse-telemetry {
  0% { transform: scale(0.95); opacity: 0.7; }
  50% { transform: scale(1.15); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.7; }
}

.hero-headline {
  font-size: 3.5rem;
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -0.035em;
  color: var(--graphite-900);
  margin-bottom: 1.5rem;
}

.sky-accent {
  color: var(--sky-blue-deep);
  position: relative;
  display: inline-block;
}

[data-theme="dark"] .sky-accent {
  color: var(--sky-blue);
}

.hero-intro-lead {
  font-size: 1.2rem;
  font-weight: 500;
  color: var(--graphite-700);
  max-width: 780px;
  margin: 0 auto 1.25rem auto;
  line-height: 1.7;
}

.hero-intro-detail {
  font-size: 1rem;
  color: var(--graphite-500);
  max-width: 820px;
  margin: 0 auto 2.75rem auto;
  line-height: 1.8;
}

/* 模拟微回弹主副 CTA 按钮 */
.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  flex-wrap: wrap;
  margin-bottom: 3.75rem;
}

.btn-primary-recoil {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.95rem 2.25rem;
  font-size: 1.05rem;
  font-weight: 700;
  color: #ffffff;
  background: var(--graphite-900);
  border: 1px solid var(--graphite-900);
  border-radius: 0.75rem;
  box-shadow: 0 10px 25px -4px rgba(15, 23, 42, 0.2);
  transition: var(--transition-recoil), background 0.2s ease, box-shadow 0.2s ease;
}

.btn-primary-recoil:hover {
  background: #000000;
  transform: translateY(-2px);
  box-shadow: 0 14px 30px -4px rgba(15, 23, 42, 0.25);
  color: #ffffff;
}

[data-theme="dark"] .btn-primary-recoil {
  background: var(--sky-blue);
  border-color: var(--sky-blue);
  color: #0a0f18;
  box-shadow: var(--shadow-sky);
}

[data-theme="dark"] .btn-primary-recoil:hover {
  background: #7dd3fc;
  color: #0a0f18;
}

/* 模拟机械按键微回弹触感 (Analog silent micro-recoil click) */
.btn-primary-recoil:active {
  transform: translateY(2px) scale(0.97);
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
}

.btn-primary-recoil svg {
  width: 1.2rem;
  height: 1.2rem;
  fill: none;
  stroke: currentColor;
  stroke-width: 2.5;
}

.btn-secondary-glide {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.95rem 2rem;
  font-size: 1.025rem;
  font-weight: 600;
  color: var(--graphite-700);
  background: var(--surface-pure);
  border: 1px solid var(--graphite-200);
  border-radius: 0.75rem;
  box-shadow: var(--shadow-frictionless);
  transition: var(--transition-recoil), border-color 0.2s ease, background 0.2s ease;
}

.btn-secondary-glide:hover {
  color: var(--graphite-900);
  border-color: var(--graphite-300);
  transform: translateY(-2px);
}

.btn-secondary-glide:active {
  transform: translateY(2px) scale(0.97);
}

/* ===================================================================
   服务器节点遥测机架 (40% 柔和静止态，临近呼吸平滑跃升至 100% 聚焦)
   Server Node Telemetry Track (Dormant 40% -> 100% Hover Proximity)
   =================================================================== */
.telemetry-rack-wrapper {
  max-width: 1040px;
  margin: 0 auto;
}

.telemetry-rack-label {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--graphite-500);
  margin-bottom: 0.75rem;
}

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

.telemetry-item {
  background: var(--surface-pure);
  border: 1px solid var(--graphite-200);
  border-radius: 0.85rem;
  padding: 1.1rem 1.25rem;
  text-align: left;
  box-shadow: var(--shadow-frictionless);
  /* 默认保持在 40% 的休眠柔和透明度，静默运行 */
  opacity: 0.42;
  transition: opacity 0.45s cubic-bezier(0.16, 1, 0.3, 1), 
              transform 0.45s cubic-bezier(0.16, 1, 0.3, 1), 
              border-color 0.3s ease, 
              box-shadow 0.3s ease;
  position: relative;
  overflow: hidden;
}

/* 临近悬停与聚焦：平滑温和呼吸至 100% 清晰聚焦 */
.telemetry-item:hover {
  opacity: 1;
  transform: translateY(-3px);
  border-color: var(--sky-blue);
  box-shadow: var(--shadow-sky);
}

.telemetry-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.35rem;
}

.telemetry-region {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--graphite-900);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.telemetry-dot {
  width: 0.45rem;
  height: 0.45rem;
  border-radius: 50%;
  background: var(--emerald-telemetry);
}

.telemetry-ping {
  font-family: var(--font-mono);
  font-size: 0.825rem;
  font-weight: 700;
  color: var(--emerald-telemetry);
}

.telemetry-type {
  font-size: 0.75rem;
  color: var(--graphite-500);
}

/* ===================================================================
   产品核心优势 (3个低阻浮动卡片)
   =================================================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.feature-glide-card {
  background: var(--surface-pure);
  border: 1px solid var(--graphite-200);
  border-radius: 1.25rem;
  padding: 2.75rem 2.25rem;
  box-shadow: var(--shadow-frictionless);
  transition: var(--transition-glide);
  display: flex;
  flex-direction: column;
}

.feature-glide-card:hover {
  transform: translateY(-8px);
  border-color: var(--graphite-300);
  box-shadow: var(--shadow-floating);
}

.feature-icon-wrapper {
  width: 3.5rem;
  height: 3.5rem;
  border-radius: 0.85rem;
  background: var(--surface-subtle);
  border: 1px solid var(--graphite-200);
  color: var(--graphite-900);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.75rem;
  transition: transform 0.25s ease, background 0.2s ease;
}

[data-theme="dark"] .feature-icon-wrapper {
  background: var(--surface-subtle);
  color: var(--sky-blue);
  border-color: var(--graphite-200);
}

.feature-glide-card:hover .feature-icon-wrapper {
  transform: scale(1.08);
  border-color: var(--sky-blue);
}

.feature-icon-wrapper svg {
  width: 1.85rem;
  height: 1.85rem;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.feature-title {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 0.85rem;
  color: var(--graphite-900);
  letter-spacing: -0.01em;
}

.feature-desc {
  font-size: 0.975rem;
  color: var(--graphite-500);
  line-height: 1.75;
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.feature-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  list-style: none;
}

.feature-tag-item {
  font-size: 0.775rem;
  font-weight: 600;
  padding: 0.25rem 0.65rem;
  background: var(--surface-subtle);
  color: var(--graphite-700);
  border-radius: 0.4rem;
  border: 1px solid var(--graphite-200);
}

/* ===================================================================
   流媒体与 AI 支持图卡展示区 (两张独立锚点图卡)
   =================================================================== */
.showcase-block-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2.25rem;
}

.showcase-glide-card {
  background: var(--surface-pure);
  border: 1px solid var(--graphite-200);
  border-radius: 1.25rem;
  padding: 2.75rem 2.25rem;
  box-shadow: var(--shadow-frictionless);
  transition: var(--transition-glide);
  display: flex;
  flex-direction: column;
}

.showcase-glide-card:hover {
  transform: translateY(-6px);
  border-color: var(--graphite-300);
  box-shadow: var(--shadow-floating);
}

.showcase-badge-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.3rem 0.8rem;
  border-radius: 9999px;
  font-size: 0.8rem;
  font-weight: 700;
  margin-bottom: 1.35rem;
  width: fit-content;
}

.badge-stream-style {
  background: rgba(239, 68, 68, 0.08);
  color: #ef4444;
  border: 1px solid rgba(239, 68, 68, 0.2);
}

.badge-ai-style {
  background: var(--sky-blue-soft);
  color: var(--sky-blue-deep);
  border: 1px solid var(--sky-blue-border);
}

[data-theme="dark"] .badge-ai-style {
  color: var(--sky-blue);
}

.showcase-title {
  font-size: 1.65rem;
  font-weight: 800;
  color: var(--graphite-900);
  margin-bottom: 0.85rem;
  letter-spacing: -0.02em;
}

.showcase-desc {
  font-size: 0.985rem;
  color: var(--graphite-500);
  line-height: 1.7;
  margin-bottom: 2rem;
}

.platforms-matrix {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.85rem;
  margin-bottom: 2rem;
}

.platform-pill-box {
  background: var(--surface-subtle);
  border: 1px solid var(--graphite-200);
  border-radius: 0.75rem;
  padding: 0.85rem 0.4rem;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.45rem;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.platform-pill-box:hover {
  transform: translateY(-2px);
  border-color: var(--sky-blue);
}

.platform-icon {
  width: 1.75rem;
  height: 1.75rem;
}

.platform-label {
  font-size: 0.775rem;
  font-weight: 600;
  color: var(--graphite-900);
}

.showcase-card-footer {
  margin-top: auto;
  padding-top: 1.25rem;
  border-top: 1px dashed var(--graphite-200);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--graphite-500);
}

.showcase-card-footer svg {
  width: 1.05rem;
  height: 1.05rem;
  stroke: var(--emerald-telemetry);
  fill: none;
  stroke-width: 2.5;
}

/* ===================================================================
   清晰套餐价格对比表 (参考真实机场实际定价与配置)
   =================================================================== */
.pricing-rack-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  align-items: stretch;
}

.price-glide-card {
  background: var(--surface-pure);
  border: 1px solid var(--graphite-200);
  border-radius: 1.25rem;
  padding: 2.25rem 1.6rem;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-frictionless);
  position: relative;
  transition: var(--transition-glide);
}

.price-glide-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-floating);
}

/* 进阶畅享版 - 真实热卖推荐高亮 */
.price-glide-card.featured {
  border-color: var(--sky-blue);
  box-shadow: var(--shadow-sky), 0 0 0 1px var(--sky-blue);
  transform: scale(1.02);
  z-index: 2;
}

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

.featured-glide-tag {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--graphite-900);
  color: #ffffff;
  font-size: 0.725rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  padding: 0.25rem 0.85rem;
  border-radius: 9999px;
  border: 1px solid var(--graphite-700);
  white-space: nowrap;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

[data-theme="dark"] .featured-glide-tag {
  background: var(--sky-blue);
  color: #0b1120;
  border-color: var(--sky-blue);
  box-shadow: 0 2px 10px rgba(56, 189, 248, 0.3);
}

.plan-header {
  text-align: center;
  margin-bottom: 1.35rem;
}

.plan-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--graphite-900);
  margin-bottom: 0.6rem;
}

.plan-price-row {
  display: flex;
  align-items: baseline;
  justify-content: center;
  margin-bottom: 0.6rem;
}

.price-symbol {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--graphite-900);
}

.price-val {
  font-size: 2.5rem;
  font-weight: 900;
  color: var(--graphite-900);
  letter-spacing: -0.04em;
  margin: 0 0.15rem;
}

.price-cycle {
  font-size: 0.85rem;
  color: var(--graphite-500);
}

.plan-traffic-pill {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--sky-blue-deep);
  background: var(--sky-blue-soft);
  border: 1px solid var(--sky-blue-border);
  padding: 0.25rem 0.75rem;
  border-radius: 0.5rem;
  display: inline-block;
  white-space: nowrap;
}

[data-theme="dark"] .plan-traffic-pill {
  color: var(--sky-blue);
}

.plan-specs-list {
  list-style: none;
  margin: 1.5rem 0 2rem 0;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.plan-spec-item {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.875rem;
  color: var(--graphite-700);
}

.plan-spec-item svg {
  width: 1.1rem;
  height: 1.1rem;
  min-width: 1.1rem;
  fill: none;
  stroke: var(--emerald-telemetry);
  stroke-width: 2.5;
}

.btn-price-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  padding: 0.85rem 1rem;
  font-size: 0.95rem;
  font-weight: 700;
  border-radius: 0.75rem;
  text-align: center;
  transition: var(--transition-recoil), background 0.2s ease, border-color 0.2s ease;
}

.btn-price-featured {
  background: var(--graphite-900);
  color: #ffffff;
  border: 1px solid var(--graphite-900);
  box-shadow: 0 4px 14px rgba(15, 23, 42, 0.2);
}

.btn-price-featured:hover {
  background: #000000;
  color: #ffffff;
}

[data-theme="dark"] .btn-price-featured {
  background: var(--sky-blue);
  color: #0b1120;
  border-color: var(--sky-blue);
}

.btn-price-outline {
  background: var(--surface-subtle);
  color: var(--graphite-900);
  border: 1px solid var(--graphite-200);
}

.btn-price-outline:hover {
  background: var(--surface-pure);
  border-color: var(--graphite-300);
}

.btn-price-action:active {
  transform: translateY(2px) scale(0.97);
}

/* ===================================================================
   用户真实评价 (Reviews)
   =================================================================== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.75rem;
}

.review-glide-card {
  background: var(--surface-pure);
  border: 1px solid var(--graphite-200);
  border-radius: 1.25rem;
  padding: 2.25rem 2rem;
  box-shadow: var(--shadow-frictionless);
  transition: var(--transition-glide);
  display: flex;
  flex-direction: column;
}

.review-glide-card:hover {
  transform: translateY(-5px);
  border-color: var(--graphite-300);
  box-shadow: var(--shadow-floating);
}

.review-stars {
  display: flex;
  gap: 0.2rem;
  color: #f59e0b;
  margin-bottom: 1.15rem;
}

.review-stars svg {
  width: 1rem;
  height: 1rem;
  fill: currentColor;
}

.review-body {
  font-size: 0.95rem;
  color: var(--graphite-700);
  line-height: 1.7;
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  border-top: 1px solid var(--graphite-200);
  padding-top: 1.25rem;
}

.author-avatar {
  width: 2.6rem;
  height: 2.6rem;
  border-radius: 50%;
  background: var(--surface-subtle);
  border: 1px solid var(--graphite-200);
  color: var(--graphite-900);
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.95rem;
}

.author-name {
  font-size: 0.925rem;
  font-weight: 700;
  color: var(--graphite-900);
}

.author-role {
  font-size: 0.8rem;
  color: var(--graphite-500);
}

/* ===================================================================
   常见问题解答 (FAQ)
   =================================================================== */
.faq-wrap {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.faq-item {
  background: var(--surface-pure);
  border: 1px solid var(--graphite-200);
  border-radius: 0.85rem;
  overflow: hidden;
  box-shadow: var(--shadow-frictionless);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.faq-item:hover {
  border-color: var(--graphite-300);
}

.faq-question {
  padding: 1.35rem 1.75rem;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--graphite-900);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
  list-style: none;
}

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

.faq-icon-arrow {
  width: 1.2rem;
  height: 1.2rem;
  transition: transform 0.25s ease;
  stroke: var(--graphite-500);
  stroke-width: 2;
  fill: none;
}

details[open] .faq-icon-arrow {
  transform: rotate(180deg);
  stroke: var(--sky-blue-deep);
}

[data-theme="dark"] details[open] .faq-icon-arrow {
  stroke: var(--sky-blue);
}

.faq-answer {
  padding: 0 1.75rem 1.5rem 1.75rem;
  font-size: 0.95rem;
  color: var(--graphite-500);
  line-height: 1.75;
  border-top: 1px solid var(--graphite-200);
  padding-top: 1.25rem;
}

/* ===================================================================
   页脚规范区 (严格仅保留 4 个标题，并在新页面打开)
   =================================================================== */
.site-footer {
  margin-top: auto;
  background: var(--surface-pure);
  border-top: 1px solid var(--graphite-200);
  padding: 3.5rem 0 2.5rem 0;
  transition: var(--transition-theme);
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 3.5rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.footer-link {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--graphite-900);
  position: relative;
  transition: color 0.2s ease;
}

.footer-link:hover {
  color: var(--sky-blue-deep);
}

[data-theme="dark"] .footer-link:hover {
  color: var(--sky-blue);
}

.footer-copy {
  text-align: center;
  font-size: 0.85rem;
  color: var(--graphite-500);
  border-top: 1px solid var(--graphite-200);
  padding-top: 2rem;
  max-width: 800px;
  margin: 0 auto;
}

/* ===================================================================
   推荐资讯 (News / Insights) 页面专属设计
   =================================================================== */
.news-filter-tabs {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 2.75rem;
}

.filter-tab-btn {
  padding: 0.45rem 1.15rem;
  border-radius: 9999px;
  font-size: 0.875rem;
  font-weight: 600;
  background: var(--surface-pure);
  border: 1px solid var(--graphite-200);
  color: var(--graphite-500);
  transition: all 0.2s ease;
}

.filter-tab-btn.active, .filter-tab-btn:hover {
  background: var(--graphite-900);
  color: #ffffff;
  border-color: var(--graphite-900);
}

[data-theme="dark"] .filter-tab-btn.active, [data-theme="dark"] .filter-tab-btn:hover {
  background: var(--sky-blue);
  color: #0b1120;
  border-color: var(--sky-blue);
}

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

.article-card {
  background: var(--surface-pure);
  border: 1px solid var(--graphite-200);
  border-radius: 1.25rem;
  padding: 2.25rem;
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-frictionless);
  transition: var(--transition-glide);
}

.article-card:hover {
  transform: translateY(-6px);
  border-color: var(--graphite-300);
  box-shadow: var(--shadow-floating);
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.8rem;
  color: var(--graphite-500);
  margin-bottom: 0.85rem;
}

.article-category {
  color: var(--sky-blue-deep);
  font-weight: 700;
  background: var(--sky-blue-soft);
  padding: 0.2rem 0.55rem;
  border-radius: 0.35rem;
}

[data-theme="dark"] .article-category {
  color: var(--sky-blue);
}

.article-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--graphite-900);
  margin-bottom: 0.75rem;
  line-height: 1.4;
}

.article-excerpt {
  font-size: 0.95rem;
  color: var(--graphite-500);
  line-height: 1.7;
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.article-footer-cta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--graphite-200);
  padding-top: 1rem;
}

.article-read-btn {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--sky-blue-deep);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

[data-theme="dark"] .article-read-btn {
  color: var(--sky-blue);
}

/* ===================================================================
   子页面通用板式 (关于我们 / 服务条款 / 隐私政策 / 网站地图)
   =================================================================== */
.subpage-hero {
  padding: 4.5rem 0 3rem 0;
  text-align: center;
  background: var(--surface-subtle);
  border-bottom: 1px solid var(--graphite-200);
}

.subpage-container {
  max-width: 880px;
  margin: 0 auto;
  padding: 3.5rem 1.75rem 5rem 1.75rem;
}

.content-block {
  background: var(--surface-pure);
  border: 1px solid var(--graphite-200);
  border-radius: 1.25rem;
  padding: 2.5rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-frictionless);
}

.content-block h2 {
  font-size: 1.45rem;
  font-weight: 700;
  color: var(--graphite-900);
  margin-bottom: 1.25rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.content-block h2 svg {
  width: 1.4rem;
  height: 1.4rem;
  color: var(--sky-blue-deep);
}

[data-theme="dark"] .content-block h2 svg {
  color: var(--sky-blue);
}

.content-block p {
  color: var(--graphite-700);
  line-height: 1.8;
  margin-bottom: 1rem;
}

.content-block ul {
  list-style-position: inside;
  color: var(--graphite-700);
  line-height: 1.8;
  margin-bottom: 1rem;
}

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

.back-home-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--sky-blue-deep);
  margin-bottom: 1.75rem;
}

[data-theme="dark"] .back-home-btn {
  color: var(--sky-blue);
}

.back-home-btn svg {
  width: 1.1rem;
  height: 1.1rem;
}

/* ===================================================================
   长篇深度科普文章 (SEO In-Depth Article) 专属设计排版
   =================================================================== */
.article-view-container {
  max-width: 960px;
  margin: 0 auto;
  padding: 3rem 1.5rem 5rem 1.5rem;
}

/* 面包屑导航 */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--graphite-500);
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.breadcrumb a {
  color: var(--graphite-700);
  transition: color 0.2s ease;
}

.breadcrumb a:hover {
  color: var(--sky-blue-deep);
}

[data-theme="dark"] .breadcrumb a:hover {
  color: var(--sky-blue);
}

.breadcrumb-separator {
  color: var(--graphite-300);
}

/* 文章头部 */
.article-header-card {
  background: var(--surface-pure);
  border: 1px solid var(--graphite-200);
  border-radius: 1.25rem;
  padding: 2.75rem 2.5rem;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-frictionless);
}

.article-hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.3rem 0.8rem;
  background: var(--sky-blue-soft);
  color: var(--sky-blue-deep);
  border: 1px solid var(--sky-blue-border);
  font-size: 0.8rem;
  font-weight: 700;
  border-radius: 9999px;
  margin-bottom: 1.25rem;
}

[data-theme="dark"] .article-hero-tag {
  color: var(--sky-blue);
}

.article-hero-title {
  font-size: 2.35rem;
  font-weight: 800;
  color: var(--graphite-900);
  line-height: 1.3;
  margin-bottom: 1.25rem;
  letter-spacing: -0.025em;
}

.article-meta-row {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  font-size: 0.875rem;
  color: var(--graphite-500);
  flex-wrap: wrap;
  border-top: 1px solid var(--graphite-200);
  padding-top: 1.25rem;
  margin-top: 1.25rem;
}

.article-meta-item {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.article-meta-item svg {
  width: 1rem;
  height: 1rem;
}

/* 目录容器 (Table of Contents) */
.article-toc-box {
  background: var(--surface-subtle);
  border: 1px solid var(--graphite-200);
  border-left: 4px solid var(--sky-blue);
  border-radius: 0.85rem;
  padding: 1.75rem 2rem;
  margin: 2rem 0 2.5rem 0;
}

.toc-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--graphite-900);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.toc-title svg {
  width: 1.2rem;
  height: 1.2rem;
  color: var(--sky-blue-deep);
}

[data-theme="dark"] .toc-title svg {
  color: var(--sky-blue);
}

.toc-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.toc-link {
  font-size: 0.95rem;
  color: var(--graphite-700);
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  transition: color 0.2s ease, transform 0.2s ease;
}

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

[data-theme="dark"] .toc-link:hover {
  color: var(--sky-blue);
}

/* 文章正文富文本 */
.article-content-card {
  background: var(--surface-pure);
  border: 1px solid var(--graphite-200);
  border-radius: 1.25rem;
  padding: 3rem 2.5rem;
  margin-bottom: 2.5rem;
  box-shadow: var(--shadow-frictionless);
  line-height: 1.85;
  color: var(--graphite-700);
}

.article-content-card h2 {
  font-size: 1.65rem;
  font-weight: 800;
  color: var(--graphite-900);
  margin: 2.5rem 0 1.25rem 0;
  padding-bottom: 0.6rem;
  border-bottom: 1px solid var(--graphite-200);
  scroll-margin-top: 5.5rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

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

.article-content-card h3 {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--graphite-900);
  margin: 1.75rem 0 0.85rem 0;
  scroll-margin-top: 5.5rem;
}

.article-content-card p {
  margin-bottom: 1.35rem;
  font-size: 1.025rem;
}

.article-content-card ul, .article-content-card ol {
  margin: 1rem 0 1.5rem 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.article-content-card li {
  font-size: 1rem;
}

.article-content-card a {
  color: var(--sky-blue-deep);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.2s ease;
}

[data-theme="dark"] .article-content-card a {
  color: var(--sky-blue);
}

.article-content-card a:hover {
  color: #0369a1;
}

/* 重点提示框与呼吁框 */
.callout-box {
  background: var(--surface-subtle);
  border: 1px solid var(--graphite-200);
  border-left: 4px solid var(--sky-blue);
  border-radius: 0.75rem;
  padding: 1.25rem 1.5rem;
  margin: 1.75rem 0;
  font-size: 0.95rem;
}

.callout-box.tip {
  border-left-color: var(--emerald-telemetry);
  background: rgba(16, 185, 129, 0.06);
}

.callout-box.warning {
  border-left-color: #f59e0b;
  background: rgba(245, 158, 11, 0.06);
}

/* 深度对比表格 */
.table-responsive {
  width: 100%;
  overflow-x: auto;
  margin: 1.75rem 0;
  border-radius: 0.75rem;
  border: 1px solid var(--graphite-200);
}

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

.article-data-table th {
  background: var(--surface-subtle);
  color: var(--graphite-900);
  font-weight: 700;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--graphite-200);
}

.article-data-table td {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--graphite-200);
  color: var(--graphite-700);
}

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

/* 常见问题解答模块 (Article FAQ) */
.article-faq-card {
  background: var(--surface-pure);
  border: 1px solid var(--graphite-200);
  border-radius: 1.25rem;
  padding: 2.75rem 2.5rem;
  margin-bottom: 2.5rem;
  box-shadow: var(--shadow-frictionless);
}

/* 相关阅读网格 (Related Articles) */
.related-posts-section {
  background: var(--surface-pure);
  border: 1px solid var(--graphite-200);
  border-radius: 1.25rem;
  padding: 2.75rem 2.5rem;
  margin-bottom: 2.5rem;
  box-shadow: var(--shadow-frictionless);
}

.related-posts-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.related-post-card {
  background: var(--surface-subtle);
  border: 1px solid var(--graphite-200);
  border-radius: 0.85rem;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.related-post-card:hover {
  transform: translateY(-4px);
  border-color: var(--sky-blue);
}

.related-post-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--graphite-900);
  margin-bottom: 0.6rem;
  line-height: 1.45;
}

.related-post-desc {
  font-size: 0.85rem;
  color: var(--graphite-500);
  line-height: 1.6;
  flex-grow: 1;
  margin-bottom: 1rem;
}

.related-post-link {
  font-size: 0.825rem;
  font-weight: 700;
  color: var(--sky-blue-deep);
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

[data-theme="dark"] .related-post-link {
  color: var(--sky-blue);
}

/* 文章底部推广横幅 */
.article-cta-box {
  background: var(--surface-subtle);
  border: 1px solid var(--graphite-200);
  border-radius: 1.25rem;
  padding: 2.5rem;
  text-align: center;
  margin-top: 2rem;
}

/* ===================================================================
   响应式媒体查询 (@media) - 确保手机端单栏优雅与触控无障碍
   =================================================================== */
@media (max-width: 1080px) {
  .pricing-rack-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
  }
  .price-glide-card.featured {
    transform: none;
  }
  .price-glide-card.featured:hover {
    transform: translateY(-6px);
  }
  .showcase-block-grid {
    grid-template-columns: 1fr;
  }
  .telemetry-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .news-articles-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .header-inner {
    height: 4.25rem;
  }
  .nav-menu {
    display: none; /* 移动端保持极速加载与清爽体验 */
  }
  .hero-headline {
    font-size: 2.25rem;
  }
  .hero-intro-lead {
    font-size: 1.05rem;
  }
  .features-grid {
    grid-template-columns: 1fr;
    gap: 1.25rem;
  }
  .telemetry-grid {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }
  .platforms-matrix {
    grid-template-columns: repeat(2, 1fr);
  }
  .pricing-rack-grid {
    grid-template-columns: 1fr;
    gap: 1.25rem;
  }
  .reviews-grid {
    grid-template-columns: 1fr;
    gap: 1.25rem;
  }
  .footer-nav {
    gap: 1.5rem;
  }
  .btn-primary-recoil, .btn-secondary-glide {
    width: 100%;
    min-height: 48px;
  }
  .btn-price-action {
    min-height: 48px;
  }
  .section {
    padding: 3.75rem 0;
  }
  .content-block {
    padding: 1.5rem;
  }
}