/* ===================================================================
   TAG 官方落地页 - 全反射光棱镜物理架构样式表 (Optical-Prism UI)
   Deep Photon-Vacuum Palette:
   - 暗黑光子真空蓝: #060811
   - 光学纯白晶体: #ffffff / #f8fafc
   - 相干内全反射蓝绿: #00f5ff
   - 斯涅尔折射微光 / 激光基准面 / 高密 Monospace 载波数据
   - 零扁平边框，重型光学石英块体 (Synthetic Quartz Slabs)
   =================================================================== */

:root {
  /* ================= 默认白天模式 (Optic Crystal Clear) ================= */
  --bg-vacuum: #f4f7fb;
  --bg-slab: #ffffff;
  --bg-slab-elevated: #ffffff;
  --bg-glass-facet: rgba(255, 255, 255, 0.88);
  --bg-subtle-mesh: #ebf1f8;

  --datum-line: rgba(0, 168, 204, 0.14);
  --datum-grid: rgba(15, 23, 42, 0.04);
  --prism-edge: rgba(0, 180, 216, 0.35);
  --prism-caustic: rgba(0, 245, 255, 0.22);
  --prism-shadow: 0 16px 40px -10px rgba(0, 78, 120, 0.12), 0 0 0 1px rgba(0, 180, 216, 0.18);

  --text-pure: #090d16;
  --text-muted: #475569;
  --text-telecom: #0284c7;
  --text-laser: #008fa3;

  --coherent-cyan: #0099aa;
  --coherent-cyan-glow: rgba(0, 153, 170, 0.25);
  --coherent-gradient: linear-gradient(135deg, #0284c7 0%, #00b4d8 50%, #06b6d4 100%);
  --laser-pulse: #0284c7;

  --accent-emerald: #059669;
  --accent-amber: #d97706;
  --accent-crimson: #e11d48;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "SF Mono", "JetBrains Mono", Consolas, "Fira Code", monospace;

  --slab-radius: 16px;
  --transition-smooth: 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

/* ================= 昼夜模式 - 深空光子真空 (Deep Photon-Vacuum Dark Mode) ================= */
[data-theme="dark"] {
  --bg-vacuum: #060811;
  --bg-slab: rgba(11, 16, 28, 0.78);
  --bg-slab-elevated: rgba(17, 24, 42, 0.85);
  --bg-glass-facet: rgba(6, 8, 17, 0.88);
  --bg-subtle-mesh: #0c1222;

  --datum-line: rgba(0, 245, 255, 0.16);
  --datum-grid: rgba(0, 245, 255, 0.05);
  --prism-edge: rgba(0, 245, 255, 0.35);
  --prism-caustic: rgba(0, 245, 255, 0.45);
  --prism-shadow: 0 24px 50px -12px rgba(0, 0, 0, 0.8), 0 0 25px rgba(0, 245, 255, 0.12);

  --text-pure: #ffffff;
  --text-muted: #8e9bb0;
  --text-telecom: #00f5ff;
  --text-laser: #00f5ff;

  --coherent-cyan: #00f5ff;
  --coherent-cyan-glow: rgba(0, 245, 255, 0.4);
  --coherent-gradient: linear-gradient(135deg, #00f5ff 0%, #00a8ff 60%, #7000ff 100%);
  --laser-pulse: #00f5ff;

  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;
  --accent-crimson: #f43f5e;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-vacuum);
  color: var(--text-pure);
  line-height: 1.65;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  transition: background-color var(--transition-smooth), color var(--transition-smooth);
}

/* 全反射光学物理激光底纹网格 (Laser Datum Plane) */
.laser-datum-plane {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background-size: 50px 50px;
  background-image: 
    linear-gradient(to right, var(--datum-grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--datum-grid) 1px, transparent 1px);
  mask-image: radial-gradient(circle at 50% 25%, black 40%, transparent 80%);
  -webkit-mask-image: radial-gradient(circle at 50% 25%, black 40%, transparent 80%);
}

/* 顶部光子全反射散射弧光 */
.prism-scatter-beam {
  position: fixed;
  top: -100px;
  left: 50%;
  transform: translateX(-50%);
  width: 90vw;
  max-width: 1300px;
  height: 500px;
  background: radial-gradient(ellipse at 50% 15%, var(--coherent-cyan-glow) 0%, rgba(112, 0, 255, 0.08) 45%, transparent 75%);
  filter: blur(80px);
  pointer-events: none;
  z-index: 0;
}

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

/* 通用容器 */
.container {
  width: 100%;
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 1;
}

/* ================= 重型合成石英晶体块 (Synthetic Quartz Slab) ================= */
/* 摆脱传统扁平卡片边框：利用斯涅尔定律折射切面、内壁全反射与动态光斑 */
.quartz-slab {
  background: var(--bg-slab);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-radius: var(--slab-radius);
  position: relative;
  box-shadow: var(--prism-shadow);
  overflow: hidden;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  border: 1px solid var(--prism-edge);
}

/* 晶体边缘斯涅尔全反射色散光效 */
.quartz-slab::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--coherent-cyan), transparent);
  opacity: 0.8;
  z-index: 3;
}

/* 鼠标实时全反射焦散层 (光束折射投射) */
.quartz-slab .slab-caustic-layer {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: radial-gradient(circle at var(--mouse-x, 50%) var(--mouse-y, 50%), var(--prism-caustic) 0%, transparent 60%);
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: 1;
  border-radius: var(--slab-radius);
}

.quartz-slab:hover .slab-caustic-layer {
  opacity: 1;
}

.quartz-slab:hover {
  transform: translateY(-4px);
  box-shadow: 0 24px 60px -12px var(--coherent-cyan-glow), 0 0 0 1px var(--coherent-cyan);
}

/* 高密度 Monospace 载波数据基准线 */
.telecom-datum-tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-telecom);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: rgba(0, 245, 255, 0.08);
  padding: 3px 10px;
  border-radius: 4px;
  border-left: 2px solid var(--coherent-cyan);
}

.telecom-datum-tag::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--coherent-cyan);
  box-shadow: 0 0 8px var(--coherent-cyan);
}

/* ================= 导航条 (Header) ================= */
.site-header {
  position: sticky;
  top: 0;
  width: 100%;
  z-index: 1000;
  background: var(--bg-glass-facet);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--datum-line);
  transition: background-color var(--transition-smooth), border-color var(--transition-smooth);
}

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

.brand-quartz-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-weight: 900;
  font-size: 1.45rem;
  letter-spacing: -0.02em;
  color: var(--text-pure);
}

.brand-prism-icon {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: var(--coherent-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #060811;
  box-shadow: 0 0 18px var(--coherent-cyan-glow);
  font-weight: 900;
  font-size: 1.15rem;
  position: relative;
}

.brand-carrier-tag {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  padding: 2px 6px;
  background: rgba(0, 245, 255, 0.12);
  color: var(--text-telecom);
  border-radius: 4px;
  font-weight: 600;
  letter-spacing: 0.05em;
  margin-left: 4px;
}

/* 导航目录 (包含首页、每个板块及“推荐资讯”) */
.nav-menu {
  display: flex;
  align-items: center;
  gap: 22px;
}

.nav-link {
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-muted);
  position: relative;
  padding: 8px 4px;
  transition: color 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

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

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: var(--coherent-cyan);
  box-shadow: 0 0 10px var(--coherent-cyan);
  transition: width 0.25s ease;
  border-radius: 2px;
}

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

/* “推荐资讯”高亮标识 */
.nav-link.nav-highlight {
  color: var(--text-pure);
  font-weight: 600;
}
.nav-link.nav-highlight .pulse-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--coherent-cyan);
  box-shadow: 0 0 8px var(--coherent-cyan);
  animation: pulse-dot 1.8s infinite;
}
@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.4; transform: scale(0.7); }
}

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

/* 精致半透明昼夜切换按钮 (无粗糙emoji，高精度光学透镜质感) */
.theme-toggle-btn {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.4);
  border: 1px solid var(--prism-edge);
  color: var(--text-pure);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}
[data-theme="dark"] .theme-toggle-btn {
  background: rgba(6, 8, 17, 0.6);
  border-color: rgba(0, 245, 255, 0.25);
  color: #00f5ff;
}
.theme-toggle-btn:hover {
  transform: scale(1.05) rotate(15deg);
  border-color: var(--coherent-cyan);
  box-shadow: 0 0 15px var(--coherent-cyan-glow);
}
.theme-toggle-btn svg {
  width: 19px;
  height: 19px;
}
.icon-sun { display: none; }
.icon-moon { display: block; }
[data-theme="dark"] .icon-sun { display: block; }
[data-theme="dark"] .icon-moon { display: none; }

/* 按钮设计 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 0.95rem;
  padding: 10px 22px;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  user-select: none;
  white-space: nowrap;
}

.btn-primary {
  background: var(--coherent-gradient);
  color: #060811 !important;
  font-weight: 800;
  border: none;
  box-shadow: 0 4px 18px var(--coherent-cyan-glow);
  position: relative;
  overflow: hidden;
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px var(--coherent-cyan-glow);
  filter: brightness(1.08);
}

.btn-prism {
  background: var(--bg-slab);
  color: var(--text-pure);
  border: 1px solid var(--prism-edge);
  box-shadow: var(--prism-shadow);
}
.btn-prism:hover {
  border-color: var(--coherent-cyan);
  color: var(--text-telecom);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 14px 34px;
  font-size: 1.05rem;
  border-radius: 10px;
}

.btn-block {
  width: 100%;
}

/* ================= 主视觉首屏 (Hero Section) ================= */
.hero-section {
  padding: 85px 0 65px;
  position: relative;
  text-align: center;
}

.hero-telecom-badge {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 6px 18px;
  border-radius: 30px;
  background: rgba(0, 245, 255, 0.08);
  border: 1px solid var(--prism-edge);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-telecom);
  margin-bottom: 24px;
}

.laser-pulse-indicator {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--coherent-cyan);
  box-shadow: 0 0 12px var(--coherent-cyan);
  animation: pulse-laser 2s infinite;
}
@keyframes pulse-laser {
  0% { transform: scale(0.9); opacity: 0.8; }
  50% { transform: scale(1.4); opacity: 1; box-shadow: 0 0 20px var(--coherent-cyan); }
  100% { transform: scale(0.9); opacity: 0.8; }
}

.hero-headline {
  font-size: clamp(2.3rem, 5.2vw, 4.2rem);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.04em;
  color: var(--text-pure);
  max-width: 980px;
  margin: 0 auto 20px;
}

.hero-headline-highlight {
  background: var(--coherent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
  padding: 0 6px;
}

.hero-subheadline {
  font-size: clamp(1.15rem, 2.2vw, 1.35rem);
  color: var(--text-telecom);
  font-weight: 600;
  max-width: 800px;
  margin: 0 auto 22px;
  letter-spacing: -0.01em;
}

/* 必须要求的“简介”模块 */
.hero-intro-card {
  max-width: 860px;
  margin: 0 auto 36px;
  padding: 24px 28px;
  text-align: left;
  border-radius: 12px;
  background: var(--bg-slab-elevated);
  border: 1px solid var(--datum-line);
  position: relative;
}
.hero-intro-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}
.hero-intro-title {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-telecom);
  letter-spacing: 0.05em;
  font-weight: 700;
}
.hero-intro-text {
  font-size: 0.98rem;
  color: var(--text-muted);
  line-height: 1.75;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 46px;
}

/* 核心通信物理参数指示条 */
.hero-telecom-metrics {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  margin-top: 20px;
}
.metric-slab {
  padding: 22px 18px;
  text-align: left;
}
.metric-datum-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.metric-val {
  font-size: 2rem;
  font-weight: 900;
  font-family: var(--font-mono);
  color: var(--text-pure);
  letter-spacing: -0.03em;
  line-height: 1.1;
}
.metric-val span {
  font-size: 1.2rem;
  color: var(--coherent-cyan);
}
.metric-sub {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 4px;
}

/* ================= 通用 Section 标头 ================= */
.section {
  padding: 90px 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 760px;
  margin: 0 auto 55px;
}

.section-datum {
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(1.9rem, 3.8vw, 2.7rem);
  font-weight: 900;
  letter-spacing: -0.03em;
  color: var(--text-pure);
  margin-bottom: 16px;
  line-height: 1.2;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* ================= 核心优势 (3个重型光学石英图文块) ================= */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}

.feature-quartz-block {
  padding: 36px 30px;
  display: flex;
  flex-direction: column;
}

.feature-optics-icon {
  width: 54px;
  height: 54px;
  border-radius: 12px;
  background: rgba(0, 245, 255, 0.08);
  border: 1px solid var(--prism-edge);
  color: var(--coherent-cyan);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
  transition: transform 0.3s ease;
}
.feature-quartz-block:hover .feature-optics-icon {
  transform: scale(1.1) rotate(5deg);
  border-color: var(--coherent-cyan);
  box-shadow: 0 0 16px var(--coherent-cyan-glow);
}
.feature-optics-icon svg {
  width: 26px;
  height: 26px;
}

.feature-title {
  font-size: 1.32rem;
  font-weight: 800;
  color: var(--text-pure);
  margin-bottom: 14px;
}

.feature-text {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 24px;
  flex-grow: 1;
}

.feature-telecom-specs {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: var(--text-telecom);
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-top: 18px;
  border-top: 1px dashed var(--datum-line);
}
.spec-chip {
  padding: 3px 8px;
  border-radius: 4px;
  background: rgba(0, 245, 255, 0.06);
  border: 1px solid var(--datum-line);
}

/* ================= 流媒体解锁图卡 & AI 原生加速图卡 ================= */
.showcase-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
}

.showcase-slab {
  padding: 38px 34px;
  display: flex;
  flex-direction: column;
}

.showcase-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 18px;
}

.showcase-title {
  font-size: 1.55rem;
  font-weight: 800;
  color: var(--text-pure);
  margin-bottom: 12px;
}

.showcase-desc {
  font-size: 0.96rem;
  color: var(--text-muted);
  line-height: 1.68;
  margin-bottom: 26px;
}

/* 高通量载波平台矩阵 (摒弃通用卡通AI图标，采用严谨光学通信指示) */
.carrier-nodes-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  margin-bottom: 28px;
}

.node-chip {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: 8px;
  background: var(--bg-subtle-mesh);
  border: 1px solid var(--datum-line);
  transition: all 0.2s ease;
}
.node-chip:hover {
  border-color: var(--coherent-cyan);
  background: var(--bg-slab-elevated);
  transform: translateY(-2px);
}

.node-indicator-glyph {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 900;
  width: 28px;
  height: 28px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.node-meta {
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.node-name {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-pure);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.node-status {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--accent-emerald);
}

.showcase-specs-list {
  margin-top: auto;
  border-top: 1px solid var(--datum-line);
  padding-top: 20px;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.spec-item {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.88rem;
  color: var(--text-muted);
}
.spec-item svg {
  width: 16px;
  height: 16px;
  color: var(--coherent-cyan);
  flex-shrink: 0;
}

/* ================= 套餐价格对比表 (参考网上 TAG 真实套餐价格) ================= */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  align-items: stretch;
  padding-top: 20px; /* 预留顶部空间，保证浮动角标完全展开不被遮挡 */
}

.pricing-slab {
  padding: 42px 30px 38px;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: visible !important; /* 关键：覆盖 quartz-slab 的 overflow:hidden，彻底解决顶部角标被切断问题 */
}

/* 热门尊贵进阶款高亮折射强化 */
.pricing-slab.featured {
  border: 2px solid var(--coherent-cyan);
  box-shadow: 0 20px 50px -10px var(--coherent-cyan-glow);
  transform: scale(1.02);
  overflow: visible !important;
}
.pricing-slab.featured:hover {
  transform: scale(1.02) translateY(-4px);
}
.pricing-slab.featured::before {
  display: none; /* 移除内部顶线，防止贯穿浮动角标 */
}

.pricing-ribbon {
  position: absolute;
  top: -15px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--coherent-gradient);
  color: #060811;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 800;
  padding: 6px 22px;
  border-radius: 20px;
  letter-spacing: 0.05em;
  white-space: nowrap;
  box-shadow: 0 4px 18px var(--coherent-cyan-glow);
  z-index: 10; /* 高于卡片边框与内部所有图层 */
  display: inline-flex;
  align-items: center;
  justify-content: center;
  line-height: 1.4;
  border: 1px solid rgba(255, 255, 255, 0.4);
}

.pricing-plan-header {
  text-align: center;
  margin-bottom: 24px;
}

.pricing-plan-tier {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-telecom);
  text-transform: uppercase;
  margin-bottom: 6px;
  letter-spacing: 0.08em;
}

.pricing-plan-name {
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--text-pure);
  margin-bottom: 6px;
}

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

.pricing-price-box {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 4px;
  margin: 18px 0 8px;
  font-family: var(--font-mono);
}
.price-symbol {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--text-pure);
}
.price-figure {
  font-size: 3.2rem;
  font-weight: 900;
  color: var(--text-pure);
  line-height: 1;
  letter-spacing: -0.04em;
}
.price-cycle {
  font-size: 0.92rem;
  color: var(--text-muted);
}

.pricing-asn-metadata {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-telecom);
  text-align: center;
  background: rgba(0, 245, 255, 0.06);
  padding: 4px 10px;
  border-radius: 4px;
  margin-bottom: 22px;
}

.pricing-features-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 32px;
  flex-grow: 1;
}

.pricing-feature-row {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 0.92rem;
  color: var(--text-muted);
}
.pricing-feature-row svg {
  width: 17px;
  height: 17px;
  color: var(--coherent-cyan);
  flex-shrink: 0;
  margin-top: 2px;
}
.pricing-feature-row strong {
  color: var(--text-pure);
}

/* ================= 用户真实评价 (Testimonials) ================= */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}

.testimonial-slab {
  padding: 32px 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.testimonial-rating {
  display: flex;
  align-items: center;
  gap: 4px;
  color: var(--accent-amber);
  margin-bottom: 14px;
}
.testimonial-rating svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

.testimonial-quote {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 24px;
}

.testimonial-telecom-profile {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-top: 16px;
  border-top: 1px solid var(--datum-line);
}

.telecom-avatar-glyph {
  width: 42px;
  height: 42px;
  border-radius: 8px;
  background: var(--coherent-gradient);
  color: #060811;
  font-weight: 900;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  flex-shrink: 0;
}

.profile-meta {
  display: flex;
  flex-direction: column;
}
.profile-name {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-pure);
}
.profile-desc {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-telecom);
}

/* ================= 常见问题 (FAQ) ================= */
.faq-wrap {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-slab {
  overflow: hidden;
  border-radius: 12px;
}

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

.faq-chevron {
  width: 20px;
  height: 20px;
  color: var(--text-telecom);
  transition: transform 0.3s ease;
  flex-shrink: 0;
}
.faq-slab.active .faq-chevron {
  transform: rotate(180deg);
}

.faq-answer-block {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

.faq-answer-content {
  padding: 0 26px 22px;
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.75;
}

/* ================= 底部 CTA 激光加速舱 ================= */
.bottom-cta-section {
  padding: 70px 0 90px;
}

.cta-optical-chamber {
  padding: 56px 40px;
  text-align: center;
  position: relative;
  border-radius: 20px;
  background: linear-gradient(135deg, rgba(0, 245, 255, 0.08) 0%, rgba(112, 0, 255, 0.06) 100%), var(--bg-slab-elevated);
  border: 1px solid var(--coherent-cyan);
  box-shadow: 0 20px 60px -15px var(--coherent-cyan-glow);
}

.cta-headline {
  font-size: clamp(2rem, 3.8vw, 2.7rem);
  font-weight: 900;
  letter-spacing: -0.03em;
  color: var(--text-pure);
  margin-bottom: 14px;
}

.cta-subtext {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 640px;
  margin: 0 auto 32px;
  line-height: 1.7;
}

/* ================= 规范页脚 (Footer) ================= */
/* 明确规定：页脚只保留这四个标题，内容打开新的页面展示 */
.site-footer {
  margin-top: auto;
  background: var(--bg-slab);
  border-top: 1px solid var(--datum-line);
  padding: 42px 0 36px;
  transition: background-color var(--transition-smooth), border-color var(--transition-smooth);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 22px;
}

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

.footer-link {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-pure);
  transition: color 0.2s ease, transform 0.2s ease;
  position: relative;
  padding: 6px 4px;
}
.footer-link:hover {
  color: var(--text-telecom);
  transform: translateY(-2px);
}

.footer-carrier-info {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-muted);
  text-align: center;
}

/* ================= 辅助页面排版 (About / Terms / Privacy / Sitemap / Insights) ================= */
.subpage-container {
  max-width: 920px;
  margin: 45px auto 85px;
  padding: 0 24px;
}

.subpage-header {
  margin-bottom: 36px;
  padding-bottom: 22px;
  border-bottom: 1px solid var(--datum-line);
}

.subpage-breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 14px;
}
.subpage-breadcrumb a {
  color: var(--text-telecom);
}

.subpage-title {
  font-size: clamp(2.1rem, 4vw, 2.7rem);
  font-weight: 900;
  letter-spacing: -0.03em;
  color: var(--text-pure);
  margin-bottom: 10px;
}

.subpage-meta {
  font-family: var(--font-mono);
  font-size: 0.84rem;
  color: var(--text-telecom);
}

.subpage-article {
  padding: 48px;
  line-height: 1.85;
}

.subpage-article h2 {
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--text-pure);
  margin-top: 38px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--datum-line);
  display: flex;
  align-items: center;
  gap: 10px;
}
.subpage-article h2:first-child {
  margin-top: 0;
}

.subpage-article h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-pure);
  margin-top: 24px;
  margin-bottom: 10px;
}

.subpage-article p {
  color: var(--text-muted);
  margin-bottom: 18px;
  font-size: 0.98rem;
}

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

.subpage-article li {
  margin-bottom: 8px;
}

.subpage-article strong {
  color: var(--text-pure);
}

.optic-notice-box {
  background: var(--bg-subtle-mesh);
  border-left: 4px solid var(--coherent-cyan);
  border-radius: 0 8px 8px 0;
  padding: 18px 22px;
  margin: 24px 0;
  font-size: 0.94rem;
  color: var(--text-muted);
}
.optic-notice-box.warning {
  border-left-color: var(--accent-crimson);
  background: rgba(225, 29, 72, 0.06);
}

/* 资讯专栏卡片 */
.insight-card {
  padding: 28px;
  margin-bottom: 24px;
  border-radius: 12px;
  display: block;
  transition: all 0.25s ease;
}
.insight-card:hover {
  transform: translateY(-3px);
  border-color: var(--coherent-cyan);
}
.insight-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-telecom);
  margin-bottom: 10px;
}
.insight-title {
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-pure);
  margin-bottom: 10px;
}
.insight-excerpt {
  font-size: 0.94rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* ================= 深度长篇 SEO 文章专属结构排版 ================= */
.article-toc {
  background: var(--bg-subtle-mesh);
  border: 1px solid var(--datum-line);
  border-left: 3px solid var(--coherent-cyan);
  border-radius: 8px;
  padding: 22px 26px;
  margin: 28px 0 36px;
}
.article-toc-title {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 800;
  color: var(--text-telecom);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.article-toc-list {
  list-style: none !important;
  padding-left: 0 !important;
  margin-bottom: 0 !important;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.article-toc-list li {
  font-size: 0.92rem;
  margin-bottom: 0 !important;
}
.article-toc-list a {
  color: var(--text-muted);
  transition: color 0.2s ease, transform 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.article-toc-list a:hover {
  color: var(--text-telecom);
  transform: translateX(4px);
}

/* 文章内部 FAQ 模块 */
.article-faq-section {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--datum-line);
}
.article-faq-card {
  background: var(--bg-subtle-mesh);
  border: 1px solid var(--datum-line);
  border-radius: 10px;
  padding: 20px 24px;
  margin-bottom: 16px;
}
.article-faq-q {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-pure);
  margin-bottom: 10px;
  display: flex;
  align-items: baseline;
  gap: 8px;
}
.article-faq-q::before {
  content: "Q:";
  font-family: var(--font-mono);
  font-weight: 900;
  color: var(--coherent-cyan);
}
.article-faq-a {
  font-size: 0.94rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* 相关阅读模块 (Related Articles) */
.related-articles-section {
  margin-top: 50px;
  padding-top: 36px;
  border-top: 1px dashed var(--datum-line);
}
.related-articles-title {
  font-size: 1.3rem;
  font-weight: 800;
  color: var(--text-pure);
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.related-articles-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
.related-article-card {
  display: block;
  padding: 18px 20px;
  background: var(--bg-subtle-mesh);
  border: 1px solid var(--datum-line);
  border-radius: 8px;
  transition: all 0.2s ease;
}
.related-article-card:hover {
  border-color: var(--coherent-cyan);
  transform: translateY(-2px);
  background: var(--bg-slab-elevated);
}
.related-article-tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-telecom);
  margin-bottom: 6px;
}
.related-article-name {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-pure);
  line-height: 1.45;
}

/* ================= 响应式媒体查询 (@media) ================= */
@media (max-width: 1024px) {
  .hero-telecom-metrics {
    grid-template-columns: repeat(2, 1fr);
  }
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .features-grid .feature-quartz-block:last-child {
    grid-column: span 2;
  }
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
    padding-top: 22px;
    gap: 32px;
  }
  .pricing-slab.featured {
    grid-column: span 2;
    transform: none;
    margin-top: 10px;
  }
  .pricing-slab.featured:hover {
    transform: translateY(-4px);
  }
  .testimonials-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .nav-menu {
    display: none; /* 移动端保持纯粹极简，留出触控交互空间 */
  }

  .header-inner {
    height: 64px;
  }

  .hero-section {
    padding: 50px 0 35px;
  }

  .hero-headline {
    font-size: 2.15rem;
  }

  .hero-subheadline {
    font-size: 1.05rem;
  }

  .hero-intro-card {
    padding: 18px 16px;
  }

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

  .hero-actions .btn {
    width: 100%;
    min-height: 48px; /* 舒适手指触控 */
  }

  /* 移动端彻底单栏卡片流 */
  .hero-telecom-metrics {
    grid-template-columns: 1fr 1fr;
    gap: 12px;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }
  .features-grid .feature-quartz-block:last-child {
    grid-column: span 1;
  }

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

  .carrier-nodes-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .pricing-grid {
    grid-template-columns: 1fr;
    padding-top: 24px;
    gap: 38px;
  }
  .pricing-slab.featured {
    grid-column: span 1;
    margin-top: 14px;
    margin-bottom: 8px;
  }

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

  .footer-nav {
    flex-direction: column;
    gap: 18px;
  }

  .subpage-article {
    padding: 26px 18px;
  }

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

  .cta-optical-chamber {
    padding: 38px 20px;
  }
}

@media (max-width: 480px) {
  .hero-telecom-metrics {
    grid-template-columns: 1fr;
  }

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

  .price-figure {
    font-size: 2.6rem;
  }
}