/* ==================================================
   寰宇云 (Huanyuyun) · 星环线路中枢
   官方网站核心样式表
   ================================================== */

:root {
  --bg-primary: #071521;
  --bg-secondary: #0D2435;
  --bg-tertiary: #123449;
  --bg-surface: #173B50;
  
  --text-primary: #F4F8FB;
  --text-body: #C1CFD8;
  --text-muted: #8FA4B3;
  
  --ring-blue: #59B8DD;
  --ring-blue-dim: rgba(89, 184, 221, 0.12);
  --node-teal: #4BC8B3;
  --node-teal-dim: rgba(75, 200, 179, 0.12);
  --accent-amber: #E4A95D;
  --accent-amber-dim: rgba(228, 169, 93, 0.12);
  
  --border-color: rgba(151, 190, 210, 0.16);
  --border-highlight: rgba(89, 184, 221, 0.4);
  --ring-line: rgba(89, 184, 221, 0.22);
  
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
  --font-mono: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace;
  
  --header-height: 70px;
  --max-content-width: 1200px;
  --article-max-width: 820px;
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 14px;
  --radius-full: 9999px;
}

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

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

body {
  background-color: var(--bg-primary);
  color: var(--text-body);
  font-family: var(--font-family);
  line-height: 1.68;
  font-size: 1rem;
  overflow-x: hidden;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* 链接与按钮 */
a {
  color: var(--ring-blue);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--text-primary);
}

img, svg {
  vertical-align: middle;
}

/* 布局容器 */
.container {
  width: 100%;
  max-width: var(--max-content-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

.article-container {
  width: 100%;
  max-width: var(--article-max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 20px;
  padding-right: 20px;
}

/* 标题样式 */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-primary);
  font-weight: 600;
  line-height: 1.35;
}

/* 模块公共头部 */
.section-wrapper {
  padding: 80px 0;
  border-bottom: 1px solid var(--border-color);
  position: relative;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--ring-blue);
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.05em;
  margin-bottom: 12px;
}

.section-tag::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--node-teal);
}

.section-title {
  font-size: 1.85rem;
  margin-bottom: 16px;
  color: var(--text-primary);
  letter-spacing: -0.01em;
}

.section-desc {
  color: var(--text-muted);
  font-size: 1rem;
  max-width: 720px;
  line-height: 1.7;
  margin-bottom: 40px;
}

/* 按钮规范 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 0.95rem;
  font-weight: 500;
  padding: 10px 22px;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  cursor: pointer;
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--ring-blue);
  color: #051019;
  border-color: var(--ring-blue);
  font-weight: 600;
}

.btn-primary:hover {
  background-color: #72c8ea;
  color: #030a10;
  box-shadow: 0 4px 14px rgba(89, 184, 221, 0.25);
}

.btn-primary:hover .btn-arrow {
  transform: translateX(4px);
}

.btn-secondary {
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
  border-color: var(--border-color);
}

.btn-secondary:hover {
  background-color: var(--bg-surface);
  border-color: var(--ring-blue);
  color: var(--ring-blue);
}

.btn-ghost {
  background: transparent;
  color: var(--ring-blue);
  border-color: var(--border-color);
}

.btn-ghost:hover {
  border-color: var(--ring-blue);
  color: var(--text-primary);
}

.btn-arrow {
  display: inline-block;
  transition: transform var(--transition-fast);
}

/* ==================================================
   Header 导航栏
   ================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  height: var(--header-height);
  background-color: rgba(7, 21, 33, 0.94);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.brand-wrapper {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand-logo-svg {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
}

.brand-text-block {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.02em;
  line-height: 1.2;
}

.brand-subtitle {
  font-size: 0.72rem;
  color: var(--text-muted);
  letter-spacing: 0.04em;
  line-height: 1.2;
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 20px;
}

.nav-link {
  color: var(--text-body);
  font-size: 0.9rem;
  font-weight: 500;
  padding: 6px 4px;
  position: relative;
  transition: color var(--transition-fast);
}

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

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--ring-blue);
  transition: width var(--transition-fast);
}

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

.header-action {
  display: flex;
  align-items: center;
}

.mobile-menu-btn {
  display: none;
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 0.9rem;
}

/* 移动端抽屉菜单 */
.mobile-nav-drawer {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(7, 21, 33, 0.98);
  backdrop-filter: blur(12px);
  z-index: 999;
  padding: 24px;
  overflow-y: auto;
  border-top: 1px solid var(--border-color);
  flex-direction: column;
  gap: 16px;
}

.mobile-nav-drawer.is-open {
  display: flex;
}

.mobile-nav-link {
  display: block;
  font-size: 1.05rem;
  color: var(--text-primary);
  padding: 12px 0;
  border-bottom: 1px solid rgba(151, 190, 210, 0.1);
}

.mobile-nav-link:hover {
  color: var(--ring-blue);
}

.mobile-cta-wrapper {
  margin-top: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

/* ==================================================
   Hero: 星环线路中枢
   ================================================== */
.hero-section {
  position: relative;
  background: radial-gradient(circle at 50% 30%, #0d273a 0%, #071521 70%);
  padding: 60px 0 70px;
  border-bottom: 1px solid var(--border-color);
  overflow: hidden;
}

.hero-content {
  text-align: center;
  max-width: 860px;
  margin: 0 auto 40px;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 4px 14px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  color: var(--ring-blue);
  font-size: 0.85rem;
  margin-bottom: 18px;
}

.hero-brand {
  font-size: 1rem;
  font-weight: 600;
  color: var(--node-teal);
  margin-bottom: 8px;
  letter-spacing: 0.1em;
}

.hero-punchline {
  font-size: 2.3rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.3;
  margin-bottom: 12px;
  letter-spacing: -0.02em;
}

.hero-sub {
  font-size: 1.05rem;
  color: var(--text-muted);
  letter-spacing: 0.05em;
  margin-bottom: 20px;
}

/* 首页唯一 H1 */
.hero-h1 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--ring-blue);
  margin-bottom: 16px;
  letter-spacing: 0.02em;
}

.hero-text {
  font-size: 1rem;
  color: var(--text-body);
  line-height: 1.75;
  max-width: 760px;
  margin: 0 auto 28px;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* 星环中枢视觉系统 (Real HTML DOM + 细弧线) */
.ring-hub-visual-wrapper {
  position: relative;
  max-width: 780px;
  margin: 30px auto 0;
  padding: 30px 20px;
}

.ring-hub-container {
  position: relative;
  width: 100%;
  aspect-ratio: 1.7 / 1;
  max-height: 380px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* 星环同心弧线背景 (SVG) */
.ring-svg-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.orbit-arc {
  fill: none;
  stroke: var(--ring-line);
  stroke-width: 1.2;
  transition: stroke 0.3s ease;
}

.orbit-arc-1 { stroke-dasharray: 220 20 180 30; }
.orbit-arc-2 { stroke-dasharray: 310 35 240 25; }
.orbit-arc-3 { stroke-dasharray: 400 40 320 30; }
.orbit-arc-4 { stroke-dasharray: 520 50 410 40; }

/* 中心与环层节点 (Real HTML DOM) */
.hub-center {
  position: relative;
  z-index: 10;
  background: var(--bg-tertiary);
  border: 2px solid var(--node-teal);
  border-radius: var(--radius-full);
  padding: 10px 22px;
  display: flex;
  align-items: center;
  gap: 10px;
  box-shadow: 0 0 20px rgba(75, 200, 179, 0.15);
}

.hub-center-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: var(--node-teal);
}

.hub-center-name {
  color: var(--text-primary);
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: 0.05em;
}

/* 环层真实DOM标签卡位 */
.hub-ring-node {
  position: absolute;
  z-index: 5;
  background: rgba(13, 36, 53, 0.92);
  border: 1px solid var(--border-color);
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-primary);
  backdrop-filter: blur(4px);
  transition: all var(--transition-fast);
}

.hub-ring-node:hover {
  border-color: var(--ring-blue);
  background: var(--bg-surface);
}

.hub-ring-node .node-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--ring-blue);
}

/* 节点在环上的自然排布 */
.node-pos-1 { top: 12%; left: 22%; }
.node-pos-2 { top: 18%; right: 20%; }
.node-pos-3 { bottom: 18%; left: 16%; }
.node-pos-4 { bottom: 12%; right: 18%; }
.node-pos-5 { top: 48%; left: 6%; }
.node-pos-6 { top: 48%; right: 6%; }

/* 移动端专用星环纵向列表 */
.mobile-ring-hierarchy {
  display: none;
  flex-direction: column;
  gap: 12px;
  width: 100%;
  margin-top: 24px;
}

.mobile-ring-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.mobile-ring-label {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.92rem;
  color: var(--text-primary);
}

.mobile-ring-badge {
  font-size: 0.75rem;
  padding: 2px 8px;
  background: var(--bg-tertiary);
  color: var(--ring-blue);
  border-radius: var(--radius-sm);
}

/* ==================================================
   第一环 / 网络接入
   ================================================== */
.ring-step-timeline {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  position: relative;
  margin-top: 30px;
}

.ring-step-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px 20px;
  position: relative;
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.ring-step-item:hover {
  border-color: var(--ring-blue);
  transform: translateY(-2px);
}

.step-num-arc {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1.5px solid var(--ring-blue);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--ring-blue);
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 16px;
  background: var(--bg-tertiary);
}

.step-title {
  font-size: 1.15rem;
  color: var(--text-primary);
  margin-bottom: 10px;
}

.step-desc {
  font-size: 0.9rem;
  color: var(--text-body);
  line-height: 1.6;
}

/* ==================================================
   第二环 / 线路体系
   ================================================== */
.data-table-wrapper {
  width: 100%;
  overflow-x: auto;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  margin-top: 24px;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.92rem;
}

.data-table th, .data-table td {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-color);
}

.data-table th {
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
  font-weight: 600;
  white-space: nowrap;
}

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

.data-table tr:hover td {
  background-color: rgba(23, 59, 80, 0.4);
}

.table-tag {
  display: inline-block;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 500;
}

.table-tag-blue { background: var(--ring-blue-dim); color: var(--ring-blue); }
.table-tag-teal { background: var(--node-teal-dim); color: var(--node-teal); }
.table-tag-amber { background: var(--accent-amber-dim); color: var(--accent-amber); }

/* ==================================================
   第三环 / 地区节点
   ================================================== */
.ring-node-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 24px;
}

.ring-node-row {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  display: grid;
  grid-template-columns: 160px 180px 1fr 1fr;
  align-items: center;
  gap: 20px;
  transition: border-color var(--transition-fast);
}

.ring-node-row:hover {
  border-color: var(--ring-blue);
}

.ring-node-tier {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ring-blue);
  font-weight: 600;
  font-size: 0.95rem;
}

.ring-node-name {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
}

.ring-node-col-label {
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.ring-node-col-val {
  font-size: 0.92rem;
  color: var(--text-body);
}

/* ==================================================
   第四环 / 应用服务 (AI与流媒体)
   ================================================== */
.app-service-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
  margin-top: 24px;
}

.service-sub-block {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px 24px;
}

.service-sub-title {
  font-size: 1.3rem;
  color: var(--text-primary);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.service-sub-desc {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-bottom: 20px;
}

.streaming-rows {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.streaming-row-item {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 14px 18px;
  display: grid;
  grid-template-columns: 160px 1fr 1fr;
  align-items: center;
  gap: 16px;
}

.streaming-name {
  font-weight: 600;
  color: var(--text-primary);
}

/* ==================================================
   客户端接入
   ================================================== */
.client-access-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-top: 24px;
}

.client-item-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 16px;
  transition: border-color var(--transition-fast);
}

.client-item-card:hover {
  border-color: var(--ring-blue);
}

.client-card-top {
  display: flex;
  align-items: center;
  gap: 12px;
}

.client-card-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--ring-blue);
}

.client-device-name {
  font-size: 1.1rem;
  color: var(--text-primary);
  font-weight: 600;
}

.client-device-type {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.client-usage-text {
  font-size: 0.9rem;
  color: var(--text-body);
  line-height: 1.6;
}

.client-action-link {
  font-size: 0.9rem;
  color: var(--ring-blue);
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* ==================================================
   套餐价格：星环轨道系统 (5档套餐)
   ================================================== */
.pricing-section {
  background: radial-gradient(circle at 80% 20%, #0d273a 0%, #071521 60%);
}

.pricing-layout-wrapper {
  margin-top: 36px;
}

/* Desktop: 左右结构 (左半圆轨道指示，右套餐信息条) */
.pricing-orbit-container {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 30px;
  align-items: center;
}

.pricing-orbit-arc-visual {
  position: relative;
  width: 100%;
  height: 380px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.pricing-orbit-svg {
  width: 100%;
  height: 100%;
}

.pricing-strips-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.pricing-strip-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 18px 24px;
  display: grid;
  grid-template-columns: 140px 130px 130px 1fr 140px;
  align-items: center;
  gap: 16px;
  transition: all var(--transition-fast);
  position: relative;
}

.pricing-strip-item:hover {
  border-color: var(--border-highlight);
  background: var(--bg-tertiary);
}

/* 轨道03 主力方案高亮 */
.pricing-strip-item.is-featured {
  border-color: var(--border-highlight);
  background: rgba(18, 52, 73, 0.65);
  box-shadow: 0 0 24px rgba(89, 184, 221, 0.12);
}

.pricing-strip-item.is-featured::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background-color: var(--node-teal);
  border-top-left-radius: var(--radius-md);
  border-bottom-left-radius: var(--radius-md);
}

.orbit-badge-col {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.orbit-badge-title {
  font-size: 0.85rem;
  color: var(--ring-blue);
  font-weight: 600;
}

.orbit-plan-name {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
}

.orbit-featured-tag {
  display: inline-block;
  background: var(--node-teal-dim);
  color: var(--node-teal);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  width: fit-content;
}

.orbit-price-col {
  display: flex;
  align-items: baseline;
  gap: 2px;
}

.orbit-price-val {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
}

.orbit-price-cycle {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.orbit-traffic-col {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--ring-blue);
}

.orbit-scenario-col {
  font-size: 0.88rem;
  color: var(--text-body);
}

.orbit-action-col {
  display: flex;
  justify-content: flex-end;
}

/* 长期轨道 (独立于4个常规轨道下方) */
.standalone-longterm-orbit {
  margin-top: 24px;
  background: linear-gradient(90deg, rgba(18, 52, 73, 0.4) 0%, rgba(13, 36, 53, 0.6) 100%);
  border: 1px dashed var(--border-highlight);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  display: grid;
  grid-template-columns: 140px 130px 130px 1fr 140px;
  align-items: center;
  gap: 16px;
}

.longterm-tag {
  display: inline-block;
  background: var(--accent-amber-dim);
  color: var(--accent-amber);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  width: fit-content;
}

/* 套餐快速建议 */
.pricing-quick-tips {
  margin-top: 30px;
  padding: 20px 24px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.quick-tip-title {
  font-weight: 600;
  color: var(--text-primary);
  font-size: 0.95rem;
}

.quick-tip-pills {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.quick-pill {
  font-size: 0.85rem;
  color: var(--text-body);
  background: var(--bg-tertiary);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
}

.quick-pill span {
  color: var(--ring-blue);
  font-weight: 600;
}

/* ==================================================
   寰宇云深度评测导读区
   ================================================== */
.review-feature-box {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 36px 32px;
  margin-top: 24px;
  position: relative;
}

.review-feature-grid {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 30px;
  align-items: center;
}

.review-feature-summary {
  font-size: 0.98rem;
  color: var(--text-body);
  line-height: 1.8;
  margin-bottom: 20px;
}

.review-outline-list {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 24px;
}

.review-outline-item {
  font-size: 0.88rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 8px;
}

.review-outline-item::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--ring-blue);
}

/* ==================================================
   环层知识索引 (9篇文章列表)
   ================================================== */
.knowledge-index-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-top: 24px;
}

.knowledge-index-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  display: grid;
  grid-template-columns: 120px 1fr 140px;
  align-items: center;
  gap: 20px;
  transition: border-color var(--transition-fast), background var(--transition-fast);
}

.knowledge-index-item:hover {
  border-color: var(--ring-blue);
  background: var(--bg-tertiary);
}

.knowledge-ring-mark {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--ring-blue);
  font-size: 0.85rem;
  font-weight: 600;
}

.knowledge-center-content {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.knowledge-category-tag {
  font-size: 0.78rem;
  color: var(--node-teal);
  font-weight: 500;
}

.knowledge-item-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.4;
}

.knowledge-item-title:hover {
  color: var(--ring-blue);
}

.knowledge-item-excerpt {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.knowledge-right-col {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 8px;
}

.knowledge-read-time {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ==================================================
   网络排障 (8步排查链)
   ================================================== */
.troubleshoot-chain {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-top: 24px;
}

.troubleshoot-step-box {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 18px 16px;
  position: relative;
}

.troubleshoot-step-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.troubleshoot-step-seq {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--ring-blue);
}

.troubleshoot-step-name {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
}

.troubleshoot-step-text {
  font-size: 0.85rem;
  color: var(--text-body);
  line-height: 1.6;
}

/* ==================================================
   FAQ 环形问答索引
   ================================================== */
.faq-accordion-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 24px;
}

.faq-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}

.faq-item.is-active {
  border-color: var(--border-highlight);
}

.faq-trigger {
  width: 100%;
  padding: 18px 24px;
  background: transparent;
  border: none;
  color: var(--text-primary);
  font-size: 1.05rem;
  font-weight: 600;
  text-align: left;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  gap: 16px;
}

.faq-trigger:hover {
  color: var(--ring-blue);
}

.faq-icon {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--ring-blue);
  font-size: 1.2rem;
  transition: transform var(--transition-fast);
}

.faq-item.is-active .faq-icon {
  transform: rotate(45deg);
}

.faq-body {
  padding: 0 24px 20px 24px;
  color: var(--text-body);
  font-size: 0.95rem;
  line-height: 1.75;
  display: none;
  border-top: 1px solid rgba(151, 190, 210, 0.08);
}

.faq-item.is-active .faq-body {
  display: block;
}

/* ==================================================
   Footer (紧凑深海军蓝，250px-320px)
   ================================================== */
.site-footer {
  background-color: #051019;
  border-top: 1px solid var(--border-color);
  padding: 40px 0 24px;
  margin-top: auto;
  font-size: 0.88rem;
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1.5fr;
  gap: 30px;
  padding-bottom: 30px;
  border-bottom: 1px solid var(--border-color);
}

.footer-brand-col {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-brand-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

.footer-brand-desc {
  color: var(--text-muted);
  line-height: 1.6;
  max-width: 280px;
}

.footer-heading {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 14px;
  letter-spacing: 0.02em;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-links a {
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--ring-blue);
}

.footer-cta-col {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

/* Footer 最底部严格固定区域 */
.footer-bottom {
  padding-top: 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-copyright {
  color: var(--text-muted);
}

.footer-friendly-links {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.friendly-label {
  color: var(--text-muted);
  font-weight: 500;
}

.friendly-link-item {
  color: var(--text-muted);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color var(--transition-fast);
}

.friendly-link-item:hover {
  color: var(--ring-blue);
}

/* ==================================================
   文章详情页排版规范 (GEO 优化 & 760px-820px)
   ================================================== */
.article-header {
  padding: 40px 0 24px;
}

.breadcrumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 16px;
  flex-wrap: wrap;
}

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

.breadcrumbs a:hover {
  color: var(--ring-blue);
}

.breadcrumbs-sep {
  color: rgba(151, 190, 210, 0.4);
}

.article-category-badge {
  display: inline-block;
  background: var(--ring-blue-dim);
  color: var(--ring-blue);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: var(--radius-sm);
  margin-bottom: 14px;
}

.article-h1 {
  font-size: 2.1rem;
  line-height: 1.35;
  color: var(--text-primary);
  margin-bottom: 16px;
  letter-spacing: -0.01em;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 18px;
  font-size: 0.85rem;
  color: var(--text-muted);
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-color);
  flex-wrap: wrap;
}

.article-lead {
  font-size: 1.05rem;
  line-height: 1.75;
  color: var(--text-body);
  margin: 20px 0;
}

/* GEO: 快速结论卡片 (Direct Answer for Search & AI Overviews) */
.geo-conclusion-box {
  background: rgba(18, 52, 73, 0.7);
  border: 1px solid var(--border-highlight);
  border-left: 4px solid var(--node-teal);
  border-radius: var(--radius-sm);
  padding: 20px 22px;
  margin: 24px 0 32px;
}

.geo-conclusion-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--node-teal);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.geo-conclusion-text {
  font-size: 0.95rem;
  color: var(--text-primary);
  line-height: 1.7;
}

/* 文章目录 */
.article-toc {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  margin: 28px 0;
}

.toc-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 12px;
}

.toc-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.toc-link {
  font-size: 0.9rem;
  color: var(--text-muted);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.toc-link:hover {
  color: var(--ring-blue);
}

/* 文章正文区域 (#0D2435, max-width: 820px) */
.article-body {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 36px 36px;
  color: var(--text-body);
  font-size: 1.02rem;
  line-height: 1.8;
  margin-bottom: 40px;
}

.article-body h2 {
  font-size: 1.55rem;
  color: var(--text-primary);
  margin: 36px 0 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(151, 190, 210, 0.15);
}

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

.article-body h3 {
  font-size: 1.25rem;
  color: var(--text-primary);
  margin: 24px 0 12px;
}

.article-body p {
  margin-bottom: 18px;
}

.article-body ul, .article-body ol {
  margin: 16px 0 20px 24px;
}

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

.article-body strong {
  color: var(--text-primary);
}

.article-body blockquote {
  border-left: 3px solid var(--ring-blue);
  background: var(--bg-tertiary);
  padding: 14px 18px;
  margin: 20px 0;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 0.95rem;
}

/* 文章内呼应商业 CTA */
.article-cta-box {
  background: linear-gradient(135deg, rgba(18, 52, 73, 0.8) 0%, rgba(13, 36, 53, 0.9) 100%);
  border: 1px solid var(--border-highlight);
  border-radius: var(--radius-md);
  padding: 24px;
  margin: 32px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.article-cta-info {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.article-cta-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
}

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

/* 上一篇 / 下一篇 导航 */
.article-pagination {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 40px;
}

.pagination-item {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 18px 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: border-color var(--transition-fast);
}

.pagination-item:hover {
  border-color: var(--ring-blue);
}

.pagination-item.next {
  text-align: right;
}

.pagination-label {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.pagination-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* 相关阅读 */
.related-reads-section {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  margin-bottom: 50px;
}

.related-title {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 16px;
}

.related-list {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.related-item a {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.92rem;
  color: var(--text-body);
}

.related-item a:hover {
  color: var(--ring-blue);
}

/* ==================================================
   分类页专用排版
   ================================================== */
.category-hero {
  padding: 50px 0 30px;
  border-bottom: 1px solid var(--border-color);
}

.category-h1 {
  font-size: 2.1rem;
  margin-bottom: 14px;
}

.category-intro {
  font-size: 1.05rem;
  color: var(--text-body);
  line-height: 1.75;
  max-width: 760px;
}

/* ==================================================
   关于我们 / 条款 / 隐私 / 404
   ================================================== */
.static-page-body {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 40px;
  margin: 30px 0 60px;
  line-height: 1.8;
}

.static-page-body h2 {
  font-size: 1.4rem;
  color: var(--text-primary);
  margin: 30px 0 14px;
  border-bottom: 1px solid rgba(151, 190, 210, 0.12);
  padding-bottom: 8px;
}

.error-404-box {
  text-align: center;
  padding: 80px 20px;
  max-width: 600px;
  margin: 0 auto;
}

.error-code {
  font-size: 5rem;
  font-weight: 800;
  color: var(--ring-blue);
  line-height: 1;
  margin-bottom: 16px;
}

.error-title {
  font-size: 1.6rem;
  color: var(--text-primary);
  margin-bottom: 16px;
}

.error-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-bottom: 30px;
}

/* ==================================================
   动画与 prefers-reduced-motion
   ================================================== */
@keyframes orbitShift {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.orbit-arc-animated {
  transform-origin: center;
  animation: orbitShift 120s linear infinite;
}

@media (prefers-reduced-motion: reduce) {
  * {
    animation: none !important;
    transition: none !important;
  }
}

/* ==================================================
   响应式断点系统 (375, 390, 430, 768, 1024, 1440)
   ================================================== */
@media (max-width: 1024px) {
  .desktop-nav { display: none; }
  .mobile-menu-btn { display: inline-flex; }
  
  .pricing-orbit-container {
    grid-template-columns: 1fr;
  }
  
  .pricing-orbit-arc-visual {
    display: none;
  }
  
  .footer-top {
    grid-template-columns: 1fr 1fr;
    gap: 30px;
  }
  
  .footer-brand-col {
    grid-column: span 2;
  }
}

@media (max-width: 768px) {
  .section-wrapper { padding: 60px 0; }
  .section-title { font-size: 1.55rem; }
  
  .hero-punchline { font-size: 1.75rem; }
  .hero-h1 { font-size: 1.05rem; }
  
  /* 移动端星环中枢改为纵向层次 */
  .ring-hub-container { display: none; }
  .mobile-ring-hierarchy { display: flex; }
  
  .ring-step-timeline {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  
  .ring-node-row {
    grid-template-columns: 1fr;
    gap: 10px;
  }
  
  .streaming-row-item {
    grid-template-columns: 1fr;
    gap: 6px;
  }
  
  .client-access-grid {
    grid-template-columns: 1fr 1fr;
    gap: 16px;
  }
  
  .troubleshoot-chain {
    grid-template-columns: 1fr 1fr;
  }
  
  /* 套餐手机端排序规范：03 -> 02 -> 01 -> 04 -> 长期 */
  .pricing-strips-list {
    display: flex;
    flex-direction: column;
  }
  
  .pricing-strip-item {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  
  .pricing-strip-item.item-order-03 { order: 1; }
  .pricing-strip-item.item-order-02 { order: 2; }
  .pricing-strip-item.item-order-01 { order: 3; }
  .pricing-strip-item.item-order-04 { order: 4; }
  
  .standalone-longterm-orbit {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  
  .orbit-action-col {
    justify-content: flex-start;
  }
  
  .knowledge-index-item {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  
  .knowledge-right-col {
    align-items: flex-start;
  }
  
  .review-feature-grid {
    grid-template-columns: 1fr;
  }
  
  .article-body {
    padding: 24px 20px;
  }
  
  .article-pagination {
    grid-template-columns: 1fr;
  }
  
  .related-list {
    grid-template-columns: 1fr;
  }
  
  .footer-top {
    grid-template-columns: 1fr;
  }
  
  .footer-brand-col {
    grid-column: span 1;
  }
  
  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }
}

@media (max-width: 430px) {
  .container { padding-left: 16px; padding-right: 16px; }
  .client-access-grid { grid-template-columns: 1fr; }
  .troubleshoot-chain { grid-template-columns: 1fr; }
  .hero-punchline { font-size: 1.5rem; }
  .hero-cta-group { flex-direction: column; width: 100%; }
  .hero-cta-group .btn { width: 100%; }
}

@media (max-width: 390px) {
  .hero-punchline { font-size: 1.4rem; }
  .section-title { font-size: 1.35rem; }
  .pricing-strip-item { padding: 14px 16px; }
  .standalone-longterm-orbit { padding: 14px 16px; }
  .data-table th, .data-table td { padding: 12px 14px; font-size: 0.85rem; }
}

@media (max-width: 375px) {
  .container { padding-left: 12px; padding-right: 12px; }
  .hero-punchline { font-size: 1.3rem; }
  .hero-tag { font-size: 0.78rem; }
  .btn { padding: 8px 16px; font-size: 0.88rem; }
  .orbit-price-val { font-size: 1.35rem; }
  .step-num-arc { width: 36px; height: 36px; font-size: 0.9rem; }
}

@media (min-width: 1440px) {
  .container { max-width: 1280px; }
  .hero-section { padding: 80px 0 90px; }
  .hero-punchline { font-size: 2.6rem; }
  .pricing-orbit-container { grid-template-columns: 280px 1fr; gap: 40px; }
}