/* ==========================================================================
   BoostNet 专线路由图谱 - 视觉与版式样式表
   色彩配比：70% 暖白/米白 | 20% 深色文字 | 10% 路线蓝/橙/绿
   ========================================================================== */

:root {
  --bg-page: #F6F2EA;
  --bg-surface: #FCFBF7;
  --bg-white: #FFFFFF;
  --text-main: #1A1D20;
  --text-body: #4E5553;
  --text-muted: #7C817D;
  --route-blue: #2457D6;
  --route-orange: #DB6648;
  --route-green: #6D7D75;
  --route-blue-light: #EEF3FC;
  --route-orange-light: #FBEFEA;
  --border-color: #DDD8CE;
  --border-subtle: #ECE7DE;
  --footer-bg: #ECE7DE;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --container-max: 1160px;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

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

a {
  color: var(--route-blue);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: #173fa8;
}

img, svg {
  vertical-align: middle;
  max-width: 100%;
  height: auto;
}

/* 布局辅助 */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 20px;
  padding-right: 20px;
}

.section-padding {
  padding-top: 56px;
  padding-bottom: 56px;
}

/* 顶部导航 Header */
.site-header {
  height: 68px;
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
}

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
}

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

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

.brand-sub {
  font-size: 0.72rem;
  color: var(--text-muted);
  font-weight: 500;
  line-height: 1.2;
}

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

.nav-link {
  font-size: 0.92rem;
  color: var(--text-main);
  font-weight: 500;
  padding: 6px 2px;
  position: relative;
  transition: color var(--transition-fast);
}

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

.nav-link.active {
  color: var(--route-blue);
  font-weight: 600;
}

.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--route-blue);
  border-radius: 1px;
}

.header-action {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* 按钮规范 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-size: 0.92rem;
  font-weight: 600;
  padding: 8px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--route-blue);
  color: #FFFFFF;
}

.btn-primary:hover {
  background-color: #173fa8;
  color: #FFFFFF;
}

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

.btn-secondary:hover {
  border-color: var(--route-blue);
  color: var(--route-blue);
}

.btn-sm {
  padding: 5px 12px;
  font-size: 0.85rem;
}

/* 移动端菜单按钮 */
.menu-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--border-color);
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-main);
  cursor: pointer;
}

.mobile-nav-panel {
  display: none;
  position: fixed;
  top: 68px;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--bg-surface);
  border-top: 1px solid var(--border-color);
  padding: 24px;
  overflow-y: auto;
  z-index: 99;
}

.mobile-nav-panel.open {
  display: block;
}

.mobile-nav-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 24px;
}

.mobile-nav-link {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
  display: block;
  padding: 8px 0;
  border-bottom: 1px solid var(--border-subtle);
}

.mobile-nav-link.active {
  color: var(--route-blue);
}

/* 线路编号与小标签 */
.route-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  font-weight: 600;
  padding: 3px 10px;
  background-color: var(--route-blue-light);
  color: var(--route-blue);
  border: 1px solid rgba(36, 87, 214, 0.2);
  border-radius: 2px;
  text-transform: none;
}

.route-tag-orange {
  background-color: var(--route-orange-light);
  color: var(--route-orange);
  border-color: rgba(219, 102, 72, 0.25);
}

.route-tag-green {
  background-color: #F0F4F2;
  color: var(--route-green);
  border-color: rgba(109, 125, 117, 0.25);
}

.route-node-pill {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 600;
  padding: 4px 10px;
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: 3px;
  color: var(--text-main);
}

/* 首页 Hero 区域 (总路线图) */
.hero-atlas {
  padding-top: 40px;
  padding-bottom: 36px;
  background: linear-gradient(180deg, var(--bg-surface) 0%, var(--bg-page) 100%);
  border-bottom: 1px solid var(--border-color);
}

.hero-header-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.hero-meta-title {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--route-blue);
  letter-spacing: 0.04em;
  display: flex;
  align-items: center;
  gap: 8px;
}

.hero-meta-year {
  font-size: 0.82rem;
  color: var(--text-muted);
  border-left: 1px solid var(--border-color);
  padding-left: 8px;
}

.hero-brand {
  font-size: 2.75rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 6px;
}

.hero-h1 {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.32;
  margin-bottom: 14px;
}

.hero-subtitle {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--route-blue);
  margin-bottom: 16px;
  line-height: 1.4;
}

.hero-desc {
  font-size: 1.05rem;
  color: var(--text-body);
  max-width: 860px;
  line-height: 1.72;
  margin-bottom: 24px;
}

.hero-ctas {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
  margin-bottom: 36px;
}

/* Hero 总路线图结构 */
.atlas-diagram-box {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  margin-bottom: 24px;
}

.atlas-diagram-title {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.main-route-line-layout {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 8px;
  background-color: var(--bg-white);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  overflow-x: auto;
}

.route-isp-cluster {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 130px;
}

.isp-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 3px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-main);
}

.isp-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--route-blue);
}

.isp-item:nth-child(2) .isp-dot {
  background-color: var(--route-orange);
}

.isp-item:nth-child(3) .isp-dot {
  background-color: var(--route-green);
}

.route-junction-svg {
  flex-shrink: 0;
  width: 48px;
  height: 96px;
}

.route-milestone-step {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 10px 18px;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  min-width: 140px;
  text-align: center;
}

.milestone-name {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
}

.milestone-sub {
  font-size: 0.76rem;
  color: var(--text-muted);
  margin-top: 2px;
}

.route-arrow-svg {
  flex-shrink: 0;
  width: 32px;
  height: 20px;
}

/* Hero 底部路线索引（一行索引，不是卡片） */
.hero-route-index-strip {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  border-top: 1px solid var(--border-color);
  padding-top: 18px;
  overflow-x: auto;
}

.route-index-item {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-body);
  white-space: nowrap;
  text-decoration: none;
  padding: 4px 8px;
  border-radius: 3px;
  transition: all var(--transition-fast);
}

.route-index-item:hover {
  background-color: var(--bg-surface);
  color: var(--route-blue);
}

.route-idx-no {
  font-weight: 700;
  color: var(--route-blue);
  font-size: 0.8rem;
}

.route-idx-name {
  font-weight: 600;
  color: var(--text-main);
}

/* 模块通用标题 */
.module-header {
  margin-bottom: 24px;
}

.module-number {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--route-blue);
  letter-spacing: 0.05em;
  margin-bottom: 6px;
  display: block;
}

.module-h2 {
  font-size: 1.55rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.35;
  letter-spacing: -0.01em;
}

.module-desc {
  font-size: 1rem;
  color: var(--text-body);
  margin-top: 8px;
  line-height: 1.68;
}

/* 线路路线图展示框 */
.route-card-box {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px;
  margin-bottom: 24px;
}

/* 纵向路线分支 (01 三网入口) */
.entrance-route-tree {
  display: flex;
  align-items: center;
  gap: 20px;
  margin: 20px 0;
  background-color: var(--bg-white);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 20px;
  overflow-x: auto;
}

.entrance-inputs {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.entrance-tag {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  font-weight: 600;
  font-size: 0.92rem;
  color: var(--text-main);
}

.entrance-target-block {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 20px;
  background-color: var(--route-blue-light);
  border: 1px solid rgba(36, 87, 214, 0.25);
  border-radius: 4px;
}

.entrance-target-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--route-blue);
}

.entrance-target-desc {
  font-size: 0.85rem;
  color: var(--text-body);
}

/* 专线路径 (02 专线路径) 线性流 */
.route-path-steps {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin: 24px 0;
  padding: 18px;
  background-color: var(--bg-white);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  overflow-x: auto;
}

.path-step-node {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  min-width: 120px;
}

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

.path-step-name {
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--text-main);
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  padding: 6px 12px;
  border-radius: 3px;
  width: 100%;
}

.path-step-arrow {
  color: var(--route-blue);
  font-weight: bold;
  font-size: 1.1rem;
}

/* 线路提示框 (小型浅橙背景，非危险警告) */
.route-notice-box {
  background-color: var(--route-orange-light);
  border: 1px solid rgba(219, 102, 72, 0.3);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  margin-top: 20px;
}

.notice-header {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--route-orange);
  margin-bottom: 6px;
}

.notice-body {
  font-size: 0.92rem;
  color: var(--text-body);
  line-height: 1.6;
}

/* 跨网路线示意 (03 跨网路线) */
.cross-network-flow {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 20px 0;
  padding: 16px;
  background-color: var(--bg-white);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  overflow-x: auto;
}

.cross-step {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 130px;
}

.cross-step-type {
  font-size: 0.76rem;
  color: var(--text-muted);
}

.cross-step-val {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-main);
  padding: 6px 10px;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: 3px;
}

/* 地区节点展示 (四条路线，非四张卡) */
.regional-nodes-lines {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin: 24px 0;
}

.region-line-row {
  display: flex;
  align-items: center;
  gap: 16px;
  background-color: var(--bg-white);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 14px 20px;
}

.region-title-h3 {
  font-size: 0.98rem;
  font-weight: 700;
  color: var(--text-main);
  min-width: 90px;
  margin: 0;
  white-space: nowrap;
}

.region-divider-line {
  flex-grow: 1;
  height: 1px;
  background-color: var(--border-color);
  position: relative;
}

.region-divider-line::after {
  content: "";
  position: absolute;
  right: 0;
  top: -3px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: var(--route-blue);
}

.region-city-list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
}

.region-city-item {
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-main);
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  padding: 4px 10px;
  border-radius: 3px;
}

/* 长期使用路线 (垂直线 + 小节点，非 Timeline 卡片) */
.time-route-track {
  position: relative;
  padding-left: 28px;
  margin: 24px 0;
}

.time-route-track::before {
  content: "";
  position: absolute;
  top: 10px;
  bottom: 10px;
  left: 7px;
  width: 2px;
  background-color: var(--border-color);
}

.time-route-item {
  position: relative;
  margin-bottom: 24px;
}

.time-route-item:last-child {
  margin-bottom: 0;
}

.time-route-node {
  position: absolute;
  left: -28px;
  top: 4px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background-color: var(--bg-white);
  border: 3px solid var(--route-blue);
}

.time-route-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 4px;
}

.time-route-text {
  font-size: 0.95rem;
  color: var(--text-body);
  line-height: 1.65;
}

/* 客户端分支路由 (07 客户端路线) */
.client-branch-tree {
  margin: 20px 0;
  padding: 20px;
  background-color: var(--bg-white);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
}

.client-branches-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-top: 16px;
}

.branch-option-box {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 18px;
}

.branch-option-box.recommend-branch {
  border-color: rgba(36, 87, 214, 0.4);
  background-color: var(--route-blue-light);
}

.branch-name {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 4px;
}

.branch-badge {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--route-blue);
  margin-bottom: 8px;
  display: inline-block;
}

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

/* AI 与流媒体平行双线路 (08 平行线路，非 Logo Wall) */
.parallel-track-wrapper {
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin: 24px 0;
}

.parallel-track-row {
  background-color: var(--bg-white);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
}

.track-label-col {
  min-width: 100px;
}

.track-label-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
}

.track-label-sub {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.track-items-flex {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}

.track-pill {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-main);
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  padding: 5px 12px;
  border-radius: 3px;
}

/* 套餐路线 (09 价格路线逐步上升) */
.pricing-route-container {
  margin: 24px 0;
}

.pricing-route-stepper {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  position: relative;
  margin-bottom: 24px;
}

.pricing-tier-node {
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 20px 18px;
  position: relative;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-fast);
}

.pricing-tier-node:hover {
  border-color: var(--route-blue);
  box-shadow: 0 4px 12px rgba(0,0,0,0.04);
}

.pricing-tier-node.featured-tier {
  border-color: var(--route-blue);
  background-color: var(--bg-surface);
}

.pricing-top-strip {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.tier-name {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
}

.tier-recommend-badge {
  font-size: 0.75rem;
  font-weight: 600;
  color: #FFFFFF;
  background-color: var(--route-blue);
  padding: 2px 8px;
  border-radius: 2px;
}

.tier-price-box {
  margin: 8px 0 12px 0;
}

.tier-price-val {
  font-size: 1.7rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.2;
}

.tier-traffic-val {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--route-blue);
  margin-top: 2px;
}

.tier-suit-list {
  font-size: 0.85rem;
  color: var(--text-body);
  line-height: 1.6;
  margin-bottom: 16px;
  flex-grow: 1;
}

/* 历史价格提示框 */
.historical-price-note {
  background-color: var(--bg-surface);
  border: 1px dashed var(--border-color);
  border-radius: var(--radius-sm);
  padding: 14px 18px;
  font-size: 0.88rem;
  color: var(--text-body);
  line-height: 1.6;
  margin-top: 16px;
}

/* 深度评测摘要模块 (10 评测) */
.review-highlight-box {
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-left: 4px solid var(--route-blue);
  border-radius: var(--radius-sm);
  padding: 24px;
  margin-bottom: 24px;
}

.review-quote {
  font-size: 1.08rem;
  font-weight: 500;
  color: var(--text-main);
  line-height: 1.75;
  margin-bottom: 16px;
}

.review-tags-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}

/* 知识文章：路线手册目录 (11 使用指南) */
.manual-index-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 24px 0;
}

.manual-index-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  background-color: var(--bg-white);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 16px 20px;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.manual-index-item:hover {
  border-color: var(--route-blue);
  background-color: var(--bg-surface);
}

.manual-left-col {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-grow: 1;
}

.manual-idx-num {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--route-blue);
  white-space: nowrap;
}

.manual-cat-badge {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-muted);
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  padding: 2px 8px;
  border-radius: 2px;
  white-space: nowrap;
}

.manual-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-main);
  line-height: 1.4;
}

.manual-index-item:hover .manual-title {
  color: var(--route-blue);
}

.manual-right-col {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-shrink: 0;
}

.manual-read-time {
  font-size: 0.82rem;
  color: var(--text-muted);
  white-space: nowrap;
}

.manual-read-action {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--route-blue);
  white-space: nowrap;
}

/* 常见问题 Accordion (12 常见问题) */
.faq-accordion-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 24px 0;
}

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

.faq-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 20px;
  background: transparent;
  border: none;
  cursor: pointer;
  text-align: left;
}

.faq-title-wrap {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.faq-num {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--route-blue);
}

.faq-question {
  font-size: 1.02rem;
  font-weight: 600;
  color: var(--text-main);
}

.faq-toggle-icon {
  font-size: 1.2rem;
  color: var(--route-blue);
  font-weight: bold;
  transition: transform var(--transition-fast);
  flex-shrink: 0;
}

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

.faq-answer-panel {
  display: none;
  padding: 0 20px 18px 46px;
  font-size: 0.95rem;
  color: var(--text-body);
  line-height: 1.7;
}

.faq-item.active .faq-answer-panel {
  display: block;
}

/* 页脚 Footer */
.site-footer {
  background-color: var(--footer-bg);
  border-top: 1px solid var(--border-color);
  padding: 48px 0 28px 0;
  margin-top: 56px;
}

.footer-top-grid {
  display: grid;
  grid-template-columns: 2fr 1.5fr 1.5fr 1.5fr;
  gap: 32px;
  margin-bottom: 36px;
}

.footer-brand-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 6px;
}

.footer-brand-desc {
  font-size: 0.88rem;
  color: var(--text-body);
  line-height: 1.6;
  margin-bottom: 16px;
}

.footer-col-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 14px;
}

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

.footer-nav-link {
  font-size: 0.88rem;
  color: var(--text-body);
  transition: color var(--transition-fast);
}

.footer-nav-link:hover {
  color: var(--route-blue);
}

.footer-bottom-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-color);
  padding-top: 20px;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.footer-links-recommend {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.footer-recommend-a {
  color: var(--text-muted);
  text-decoration: underline;
}

.footer-recommend-a:hover {
  color: var(--route-blue);
}

/* ==========================================================================
   文章页与分类页专门样式
   ========================================================================== */

/* 面包屑导航 */
.breadcrumb-nav {
  padding: 16px 0;
  font-size: 0.85rem;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border-subtle);
  margin-bottom: 32px;
}

.breadcrumb-list {
  list-style: none;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

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

.breadcrumb-item a:hover {
  color: var(--route-blue);
}

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

.breadcrumb-item.current {
  color: var(--text-main);
  font-weight: 500;
}

/* 文章头部 */
.article-header {
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
}

.article-header-meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 12px;
}

.article-h1 {
  font-size: 2.1rem;
  font-weight: 800;
  color: var(--text-main);
  line-height: 1.3;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.article-lead {
  font-size: 1.12rem;
  color: var(--text-body);
  line-height: 1.75;
  margin-bottom: 20px;
}

.article-author-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* 快速结论框 (Direct Answer for SEO / GEO) */
.quick-conclusion-box {
  background-color: var(--route-blue-light);
  border: 1px solid rgba(36, 87, 214, 0.25);
  border-left: 4px solid var(--route-blue);
  border-radius: var(--radius-sm);
  padding: 20px 24px;
  margin-bottom: 32px;
}

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

.conclusion-body {
  font-size: 0.98rem;
  color: var(--text-main);
  line-height: 1.72;
}

/* 本文目录 (Table of Contents) */
.article-toc-box {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 20px 24px;
  margin-bottom: 36px;
}

.toc-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.toc-list {
  list-style: none;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px 24px;
}

.toc-item a {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-size: 0.9rem;
  color: var(--text-body);
}

.toc-item a:hover {
  color: var(--route-blue);
}

.toc-num {
  font-weight: 700;
  color: var(--route-blue);
  font-size: 0.82rem;
}

/* 文章正文区域 */
.article-content {
  font-size: 1.05rem;
  color: var(--text-body);
  line-height: 1.8;
}

.article-content h2 {
  font-size: 1.55rem;
  font-weight: 700;
  color: var(--text-main);
  margin-top: 48px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
  line-height: 1.35;
}

.article-content h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin-top: 32px;
  margin-bottom: 12px;
}

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

.article-content ul, .article-content ol {
  margin-bottom: 24px;
  padding-left: 24px;
}

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

.article-content blockquote {
  background-color: var(--bg-surface);
  border-left: 4px solid var(--route-orange);
  padding: 16px 20px;
  margin: 24px 0;
  font-style: normal;
  color: var(--text-main);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

/* 文章内表格规范 */
.table-wrapper {
  overflow-x: auto;
  margin: 28px 0;
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
}

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

.comparison-table th {
  background-color: var(--bg-surface);
  color: var(--text-main);
  font-weight: 700;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border-color);
}

.comparison-table td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border-subtle);
  color: var(--text-body);
}

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

.comparison-table tr:hover td {
  background-color: var(--bg-surface);
}

/* 文章内商业行动提示卡 */
.article-cta-box {
  background: linear-gradient(135deg, var(--bg-surface) 0%, var(--route-blue-light) 100%);
  border: 1px solid rgba(36, 87, 214, 0.25);
  border-radius: var(--radius-md);
  padding: 28px;
  margin: 40px 0;
  text-align: center;
}

.article-cta-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 8px;
}

.article-cta-desc {
  font-size: 0.95rem;
  color: var(--text-body);
  max-width: 600px;
  margin: 0 auto 20px auto;
}

/* 文章底部：相关阅读 */
.related-articles-section {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--border-color);
}

.related-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 20px;
}

.related-articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.related-card {
  background-color: var(--bg-white);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 16px;
  text-decoration: none;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-fast);
}

.related-card:hover {
  border-color: var(--route-blue);
  background-color: var(--bg-surface);
}

.related-card-cat {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.related-card-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
  line-height: 1.45;
  margin-bottom: 8px;
}

.related-card:hover .related-card-title {
  color: var(--route-blue);
}

/* 分类页面样式 */
.category-hero {
  padding: 40px 0 28px 0;
  background-color: var(--bg-surface);
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 40px;
}

.category-h1 {
  font-size: 2rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 12px;
}

.category-desc {
  font-size: 1.05rem;
  color: var(--text-body);
  max-width: 800px;
  line-height: 1.7;
}

/* 单页标准容器 (About, Terms, Privacy, Sitemap, 404) */
.page-container {
  padding-top: 40px;
  padding-bottom: 60px;
}

.page-card {
  background-color: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 36px 40px;
}

.page-h1 {
  font-size: 2rem;
  font-weight: 800;
  color: var(--text-main);
  margin-bottom: 20px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border-color);
}

/* ==========================================================================
   响应式断点与无障碍适配
   支持：375px, 390px, 430px, 768px, 1024px, 1440px
   ========================================================================== */

@media (max-width: 992px) {
  .main-nav {
    display: none;
  }
  .menu-toggle {
    display: block;
  }
  .pricing-route-stepper {
    grid-template-columns: repeat(2, 1fr);
  }
  .footer-top-grid {
    grid-template-columns: 1fr 1fr;
  }
  .related-articles-grid {
    grid-template-columns: 1fr;
  }
  .toc-list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .hero-brand {
    font-size: 2.2rem;
  }
  .hero-h1 {
    font-size: 1.45rem;
  }
  .hero-subtitle {
    font-size: 1.1rem;
  }
  .main-route-line-layout {
    flex-direction: column;
    align-items: stretch;
  }
  .route-isp-cluster {
    width: 100%;
  }
  .route-junction-svg {
    transform: rotate(90deg);
    margin: 4px auto;
  }
  .route-arrow-svg {
    transform: rotate(90deg);
    margin: 4px auto;
  }
  .route-path-steps {
    flex-direction: column;
  }
  .path-step-node {
    width: 100%;
  }
  .path-step-arrow {
    transform: rotate(90deg);
    margin: 4px 0;
  }
  .cross-network-flow {
    flex-direction: column;
    align-items: stretch;
  }
  .client-branches-grid {
    grid-template-columns: 1fr;
  }
  .pricing-route-stepper {
    display: flex;
    flex-direction: column;
  }
  .pricing-tier-node.featured-tier {
    order: -1; /* 手机端优先展示推荐的标准套餐 */
  }
  .manual-index-item {
    flex-direction: column;
    align-items: flex-start;
  }
  .manual-right-col {
    width: 100%;
    justify-content: space-between;
    border-top: 1px solid var(--border-subtle);
    padding-top: 8px;
    margin-top: 4px;
  }
  .footer-top-grid {
    grid-template-columns: 1fr;
  }
  .footer-bottom-bar {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }
  .page-card {
    padding: 24px 18px;
  }
}

@media (max-width: 480px) {
  .hero-brand {
    font-size: 1.85rem;
  }
  .hero-h1 {
    font-size: 1.3rem;
  }
  .btn {
    width: 100%;
  }
  .hero-ctas {
    flex-direction: column;
    width: 100%;
  }
  .hero-ctas .btn {
    width: 100%;
  }
  .region-line-row {
    flex-direction: column;
    align-items: flex-start;
  }
  .region-divider-line {
    display: none;
  }
  .parallel-track-row {
    flex-direction: column;
    align-items: flex-start;
  }
}

/* 减少动态效果无障碍模式 */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}