/* ==================================================
   River VPN - 第3套完整独立设计：编辑索引系统
   ================================================== */

:root {
  /* 主配色系统 - 75% 暖白/白，15% 墨黑/雾蓝/青灰绿，10% 赤陶 */
  --bg-main: #FBFAF6;
  --bg-white: #FFFFFF;
  --bg-secondary: #F4F2EC;
  --text-main: #202629;
  --text-body: #5E666A;
  --text-muted: #8A9092;
  --mist-blue: #506F7C;
  --deep-mist-blue: #405A64;
  --sage-green: #647A70;
  --deep-sage-green: #4F625A;
  --terracotta: #B56F4E;
  --light-blue: #EFF3F4;
  --light-green: #F0F3F0;
  --light-terracotta: #F7EDE8;
  --border: #E4E0D7;
  --border-light: #ECE8E0;
  --highlight-bg: #EFF3F1;

  /* 字体系统 - 杂志/手册/编辑感 */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  --font-mono: "SF Mono", "Segoe UI Mono", Menlo, Consolas, monospace;

  /* 间距与结构 */
  --container-max: 1200px;
  --container-narrow: 820px;
  --header-height: 72px;
  --transition-fast: 0.18s ease;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-main);
  font-size: 1.0625rem; /* 17px */
  line-height: 1.88;
  font-weight: 400;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* 链接与排版基础 */
a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast), border-color var(--transition-fast), background-color var(--transition-fast);
}

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

p {
  color: var(--text-body);
  margin-bottom: 1.25rem;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--text-main);
  font-weight: 600;
  line-height: 1.35;
  letter-spacing: -0.01em;
}

h1 {
  font-size: clamp(2.25rem, 3.8vw + 1rem, 3.6rem);
  font-weight: 700;
  line-height: 1.25;
}

h2 {
  font-size: clamp(1.75rem, 2.2vw + 0.8rem, 2.35rem);
  font-weight: 600;
  line-height: 1.3;
}

h3 {
  font-size: clamp(1.3rem, 1.5vw + 0.6rem, 1.65rem);
  font-weight: 600;
}

/* 编号系统规范 */
.index-num {
  font-size: 0.875rem; /* 14px */
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--sage-green);
  font-feature-settings: "tnum";
  font-variant-numeric: tabular-nums;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.index-num::after {
  content: "";
  display: inline-block;
  width: 12px;
  height: 1px;
  background-color: var(--border);
}

.index-badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  padding: 0.15rem 0.55rem;
  border-radius: 2px;
  background-color: var(--light-blue);
  color: var(--mist-blue);
  border: 1px solid rgba(80, 111, 124, 0.2);
}

.index-badge.terracotta {
  background-color: var(--light-terracotta);
  color: var(--terracotta);
  border-color: rgba(181, 111, 78, 0.25);
}

.index-badge.sage {
  background-color: var(--light-green);
  color: var(--deep-sage-green);
  border-color: rgba(100, 122, 112, 0.25);
}

/* 容器布局 */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.75rem;
  padding-right: 1.75rem;
}

.container-narrow {
  width: 100%;
  max-width: var(--container-narrow);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.75rem;
  padding-right: 1.75rem;
}

/* 按钮规范 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.65rem 1.4rem;
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  border-radius: 2px;
  border: 1px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  transition: all var(--transition-fast);
}

.btn-primary {
  background-color: var(--text-main);
  color: #FFFFFF;
  border-color: var(--text-main);
}

.btn-primary:hover {
  background-color: var(--deep-mist-blue);
  border-color: var(--deep-mist-blue);
  color: #FFFFFF;
}

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

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

.btn-terracotta {
  background-color: var(--terracotta);
  color: #FFFFFF;
  border-color: var(--terracotta);
}

.btn-terracotta:hover {
  background-color: #9E5D3E;
  border-color: #9E5D3E;
  color: #FFFFFF;
}

.btn-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--mist-blue);
  padding: 0;
  background: transparent;
  border: none;
}

.btn-link:hover {
  color: var(--terracotta);
}

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

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

/* ==================================================
   Header 导航规范
   ================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--bg-main);
  border-bottom: 1px solid var(--border);
  height: var(--header-height);
  display: flex;
  align-items: center;
}

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

.header-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-shrink: 0;
}

.header-logo {
  height: 42px;
  width: auto;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-link {
  font-size: 0.9375rem;
  color: var(--text-main);
  font-weight: 500;
  padding: 0.5rem 0.15rem;
  position: relative;
  transition: color var(--transition-fast);
}

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

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

.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: -16px;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--mist-blue);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-shrink: 0;
}

.menu-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border);
  padding: 0.5rem 0.75rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-main);
  cursor: pointer;
  border-radius: 2px;
}

/* 移动端抽屉菜单 */
.mobile-drawer {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--bg-main);
  border-top: 1px solid var(--border);
  z-index: 99;
  padding: 2rem 1.75rem;
  overflow-y: auto;
}

.mobile-drawer.is-open {
  display: block;
}

.mobile-nav-list {
  list-style: none;
  display: flex;
  flex-direction: column;
}

.mobile-nav-item {
  border-bottom: 1px solid var(--border);
}

.mobile-nav-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
  font-size: 1.0625rem;
  font-weight: 500;
  color: var(--text-main);
}

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

.mobile-drawer-cta {
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

/* ==================================================
   Hero 核心：大型编辑索引
   ================================================== */
.hero-section {
  padding-top: 3.5rem;
  padding-bottom: 4.5rem;
  border-bottom: 1px solid var(--border);
  background-color: var(--bg-main);
}

.hero-meta-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8125rem;
  color: var(--text-muted);
  letter-spacing: 0.08em;
  font-weight: 600;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 2.5rem;
}

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

.hero-meta-tag::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  background-color: var(--terracotta);
  border-radius: 50%;
}

.hero-content {
  margin-bottom: 3.5rem;
}

.hero-brand-title {
  font-size: clamp(3rem, 5.5vw + 1rem, 4.6rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.1;
  color: var(--text-main);
  margin-bottom: 1.25rem;
}

.hero-lead-h1 {
  font-size: clamp(1.4rem, 2vw + 0.8rem, 2rem);
  font-weight: 600;
  line-height: 1.45;
  color: var(--text-main);
  margin-bottom: 0.75rem;
}

.hero-subhead {
  font-size: 1.0625rem;
  color: var(--mist-blue);
  font-weight: 500;
  letter-spacing: 0.04em;
  margin-bottom: 1.5rem;
}

.hero-desc {
  max-width: 820px;
  font-size: 1.125rem;
  line-height: 1.85;
  color: var(--text-body);
  margin-bottom: 2rem;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

/* Hero 首页大型索引 (00-09) */
.hero-index-wrapper {
  margin-top: 3.5rem;
}

.hero-index-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--text-main);
  margin-bottom: 0;
}

.hero-index-heading {
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--text-main);
}

.hero-index-columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  column-gap: 2.5rem;
}

.index-column {
  display: flex;
  flex-direction: column;
}

.hero-index-item {
  display: grid;
  grid-template-columns: 36px 110px 1fr 32px;
  align-items: center;
  height: 60px;
  border-bottom: 1px solid var(--border);
  transition: background-color var(--transition-fast), padding-left var(--transition-fast);
  padding: 0 0.5rem;
}

.hero-index-item:hover {
  background-color: var(--bg-secondary);
  padding-left: 0.85rem;
}

.hero-index-item .num {
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--sage-green);
  font-feature-settings: "tnum";
}

.hero-index-item .title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
}

.hero-index-item .desc {
  font-size: 0.875rem;
  color: var(--text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  padding-right: 0.5rem;
}

.hero-index-item .arrow {
  font-size: 1rem;
  color: var(--text-muted);
  text-align: right;
  transition: transform var(--transition-fast), color var(--transition-fast);
}

.hero-index-item:hover .arrow {
  transform: translateX(4px);
  color: var(--text-main);
}

/* ==================================================
   通用编辑段落与区块标题规范
   ================================================== */
.section {
  padding-top: 5rem;
  padding-bottom: 5rem;
  border-bottom: 1px solid var(--border);
}

.section-header {
  margin-bottom: 3rem;
}

.section-tag {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--sage-green);
  letter-spacing: 0.1em;
  margin-bottom: 0.85rem;
}

.section-tag::after {
  content: "";
  display: inline-block;
  width: 24px;
  height: 1px;
  background-color: var(--border);
}

.section-title {
  font-size: clamp(1.65rem, 2.2vw + 0.6rem, 2.25rem);
  font-weight: 700;
  color: var(--text-main);
  line-height: 1.35;
  margin-bottom: 1rem;
}

.section-lead {
  font-size: 1.0625rem;
  line-height: 1.85;
  color: var(--text-body);
  max-width: 820px;
}

.geo-direct-answer {
  background-color: var(--bg-white);
  border-left: 3px solid var(--sage-green);
  padding: 1.25rem 1.5rem;
  margin-bottom: 2rem;
  font-size: 1.05rem;
  line-height: 1.85;
  color: var(--text-main);
  border-top: 1px solid var(--border);
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.geo-direct-answer strong {
  color: var(--deep-sage-green);
  font-weight: 600;
}

/* ==================================================
   01 / 价格目录规范 (横向结构行，无卡片，无连续带)
   ================================================== */
.price-directory {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--text-main);
}

.price-row {
  display: grid;
  grid-template-columns: 80px 130px 140px 1fr 140px 140px;
  align-items: center;
  padding: 1.4rem 1.25rem;
  border-bottom: 1px solid var(--border);
  background-color: var(--bg-white);
  transition: background-color var(--transition-fast);
}

.price-row:hover {
  background-color: var(--bg-secondary);
}

.price-row.is-featured {
  background-color: var(--highlight-bg);
  border-left: 3px solid var(--sage-green);
}

.price-row-id {
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--sage-green);
  letter-spacing: 0.08em;
}

.price-row-name {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.price-name-text {
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--text-main);
}

.price-row-traffic {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--mist-blue);
}

.price-row-fit {
  font-size: 0.9rem;
  color: var(--text-body);
  padding-right: 1rem;
}

.price-row-cost {
  text-align: right;
  padding-right: 1rem;
}

.price-number {
  font-size: 1.85rem;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.price-period {
  font-size: 0.875rem;
  color: var(--text-muted);
}

.price-row-cta {
  text-align: right;
}

.price-decision-guide {
  margin-top: 2rem;
  padding: 1.5rem;
  background-color: var(--bg-white);
  border: 1px solid var(--border);
}

.price-decision-title {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.75rem;
  letter-spacing: 0.04em;
}

.price-decision-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
}

.price-decision-item {
  font-size: 0.875rem;
  color: var(--text-body);
  line-height: 1.6;
}

.price-decision-item strong {
  color: var(--text-main);
}

/* ==================================================
   02 / 设备档案规范 (Dossier Layouts)
   ================================================== */
.device-dossiers {
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

.device-dossier {
  background-color: var(--bg-white);
  border: 1px solid var(--border);
  padding: 2.25rem 2.5rem;
}

.dossier-top {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  border-bottom: 1px solid var(--border);
  padding-bottom: 1rem;
  margin-bottom: 1.5rem;
}

.dossier-header-left {
  display: flex;
  align-items: baseline;
  gap: 1rem;
}

.dossier-id {
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--sage-green);
  letter-spacing: 0.08em;
}

.dossier-name {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-main);
}

.dossier-purpose {
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* 档案视觉变化 */
.dossier-grid-two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-bottom: 1.5rem;
}

.dossier-vertical-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.dossier-compact-index {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.compact-chip {
  display: inline-flex;
  align-items: center;
  padding: 0.4rem 0.85rem;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-main);
}

.dossier-notes-layout {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 2rem;
  margin-bottom: 1.5rem;
}

.dossier-col h4 {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.5rem;
}

.dossier-col ul {
  list-style: none;
  font-size: 0.9rem;
  color: var(--text-body);
}

.dossier-col ul li {
  position: relative;
  padding-left: 1.2rem;
  margin-bottom: 0.4rem;
}

.dossier-col ul li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--text-muted);
}

.dossier-footer {
  display: flex;
  justify-content: flex-end;
  border-top: 1px solid var(--border-light);
  padding-top: 1rem;
}

/* ==================================================
   03 & 04 & 05 / 表格与目录索引规范 (AI、流媒体、节点)
   ================================================== */
.directory-table {
  width: 100%;
  border-collapse: collapse;
  border-top: 1px solid var(--text-main);
  background-color: var(--bg-white);
}

.directory-table th {
  text-align: left;
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--text-main);
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border);
  background-color: var(--bg-secondary);
}

.directory-table td {
  padding: 1.15rem 1.25rem;
  border-bottom: 1px solid var(--border);
  font-size: 0.9375rem;
  color: var(--text-body);
  vertical-align: middle;
}

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

.directory-table .cell-id {
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--sage-green);
  letter-spacing: 0.06em;
  font-feature-settings: "tnum";
  width: 70px;
}

.directory-table .cell-name {
  font-weight: 600;
  color: var(--text-main);
  width: 170px;
}

.directory-table .cell-action {
  text-align: right;
  width: 130px;
}

/* ==================================================
   06 / 线路知识规范 (语义化 Table)
   ================================================== */
.line-knowledge-table {
  width: 100%;
  border-collapse: collapse;
  border-top: 1px solid var(--text-main);
  background-color: var(--bg-white);
}

.line-knowledge-table th {
  text-align: left;
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--text-main);
  padding: 1.1rem 1.25rem;
  border-bottom: 1px solid var(--border);
  background-color: var(--bg-secondary);
}

.line-knowledge-table td {
  padding: 1.35rem 1.25rem;
  border-bottom: 1px solid var(--border);
  font-size: 0.9375rem;
  color: var(--text-body);
  line-height: 1.75;
  vertical-align: top;
}

.line-knowledge-table .line-id-cell {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--sage-green);
  width: 60px;
}

.line-knowledge-table .line-name-cell {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-main);
  width: 110px;
}

/* ==================================================
   07 / River VPN 评测特写展板
   ================================================== */
.review-feature-box {
  background-color: var(--bg-white);
  border: 1px solid var(--border);
  padding: 3rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

.review-feature-left h3 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 1rem;
  line-height: 1.35;
}

.review-feature-left p {
  font-size: 1rem;
  line-height: 1.85;
  margin-bottom: 1.5rem;
}

.review-feature-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.8125rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border);
  padding-top: 1rem;
  margin-top: 1.5rem;
}

.review-feature-right {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border);
  padding: 1.75rem;
}

.review-outline-title {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--text-main);
  letter-spacing: 0.08em;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

.review-outline-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.review-outline-item {
  font-size: 0.875rem;
  color: var(--text-body);
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.review-outline-item::before {
  content: "§";
  color: var(--sage-green);
  font-weight: 700;
}

/* ==================================================
   08 / 内容文章目录索引规范 (9篇SEO文章)
   ================================================== */
.articles-editorial-index {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--text-main);
}

.article-index-row {
  display: grid;
  grid-template-columns: 60px 130px 1fr 90px 130px;
  align-items: center;
  padding: 1.25rem 1rem;
  border-bottom: 1px solid var(--border);
  background-color: var(--bg-white);
  transition: background-color var(--transition-fast), padding-left var(--transition-fast);
}

.article-index-row:hover {
  background-color: var(--bg-secondary);
  padding-left: 1.35rem;
}

.article-row-id {
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--sage-green);
  font-feature-settings: "tnum";
}

.article-row-category {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--mist-blue);
}

.article-row-title {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
  padding-right: 1.5rem;
}

.article-row-readtime {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.article-row-action {
  text-align: right;
}

/* ==================================================
   09 / 网络排障故障索引规范 (T01-T08)
   ================================================== */
.troubleshooting-index {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--text-main);
}

.trouble-row {
  display: grid;
  grid-template-columns: 70px 140px 1fr 1.2fr;
  align-items: baseline;
  padding: 1.35rem 1.25rem;
  border-bottom: 1px solid var(--border);
  background-color: var(--bg-white);
}

.trouble-row:hover {
  background-color: var(--bg-secondary);
}

.trouble-id {
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--terracotta);
  letter-spacing: 0.08em;
}

.trouble-item {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-main);
}

.trouble-symptom {
  font-size: 0.9rem;
  color: var(--text-body);
  padding-right: 1.5rem;
}

.trouble-action {
  font-size: 0.9rem;
  color: var(--text-body);
}

.trouble-action strong {
  color: var(--deep-sage-green);
}

/* ==================================================
   10 / 常见问题 FAQ 规范
   ================================================== */
.faq-index {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--text-main);
}

.faq-row {
  border-bottom: 1px solid var(--border);
  background-color: var(--bg-white);
}

.faq-trigger {
  width: 100%;
  display: grid;
  grid-template-columns: 60px 1fr 32px;
  align-items: center;
  text-align: left;
  padding: 1.25rem 1rem;
  background: none;
  border: none;
  cursor: pointer;
  font-family: inherit;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
  transition: background-color var(--transition-fast);
}

.faq-trigger:hover {
  background-color: var(--bg-secondary);
}

.faq-id {
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--sage-green);
  letter-spacing: 0.08em;
}

.faq-question {
  padding-right: 1rem;
}

.faq-icon {
  font-size: 1.25rem;
  font-weight: 400;
  color: var(--text-muted);
  text-align: right;
  transition: transform var(--transition-fast);
}

.faq-row.is-open .faq-icon {
  transform: rotate(45deg);
  color: var(--terracotta);
}

.faq-answer {
  display: none;
  padding: 0 1rem 1.5rem 5.75rem;
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--text-body);
}

.faq-row.is-open .faq-answer {
  display: block;
}

/* ==================================================
   文章详情页规范 (高级编辑阅读感)
   ================================================== */
.article-page {
  padding-top: 2.5rem;
  padding-bottom: 5rem;
}

.breadcrumb-nav {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

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

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

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

.article-header {
  border-bottom: 1px solid var(--border);
  padding-bottom: 2rem;
  margin-bottom: 2.5rem;
}

.article-header-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.article-title {
  font-size: clamp(2rem, 3.2vw + 1rem, 2.85rem);
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 1.25rem;
}

.article-lead {
  font-size: 1.125rem;
  line-height: 1.85;
  color: var(--text-body);
  margin-bottom: 1.5rem;
}

.article-info-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.article-info-item strong {
  color: var(--text-main);
}

/* 文章主体布局：正文 + 右侧轻量目录 (220px) */
.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 240px;
  gap: 3.5rem;
  align-items: start;
}

.article-content {
  max-width: 820px;
  background-color: var(--bg-white);
  border: 1px solid var(--border);
  padding: 2.5rem 3rem;
}

.article-content h2 {
  font-size: 1.65rem;
  font-weight: 700;
  margin-top: 2.75rem;
  margin-bottom: 1rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border-light);
  line-height: 1.35;
}

.article-content h2:first-of-type {
  margin-top: 0;
  padding-top: 0;
  border-top: none;
}

.article-content h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin-top: 1.75rem;
  margin-bottom: 0.75rem;
}

.article-content p {
  margin-bottom: 1.35rem;
}

.article-content ul, 
.article-content ol {
  margin-bottom: 1.5rem;
  padding-left: 1.5rem;
  color: var(--text-body);
}

.article-content li {
  margin-bottom: 0.5rem;
  line-height: 1.8;
}

.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0 2rem 0;
  border: 1px solid var(--border);
}

.article-content th {
  background-color: var(--bg-secondary);
  padding: 0.75rem 1rem;
  font-size: 0.875rem;
  font-weight: 600;
  border: 1px solid var(--border);
  text-align: left;
}

.article-content td {
  padding: 0.75rem 1rem;
  font-size: 0.9rem;
  border: 1px solid var(--border);
  color: var(--text-body);
}

.article-sidebar {
  position: sticky;
  top: 96px;
}

.sidebar-toc {
  background-color: var(--bg-white);
  border: 1px solid var(--border);
  padding: 1.5rem;
}

.sidebar-toc-title {
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--text-main);
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

.sidebar-toc-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.sidebar-toc-link {
  font-size: 0.85rem;
  color: var(--text-body);
  display: block;
  line-height: 1.45;
  transition: color var(--transition-fast), padding-left var(--transition-fast);
}

.sidebar-toc-link:hover,
.sidebar-toc-link.is-active {
  color: var(--mist-blue);
  font-weight: 600;
  padding-left: 0.35rem;
}

.mobile-toc-toggle {
  display: none;
  width: 100%;
  padding: 0.85rem 1.25rem;
  background-color: var(--bg-white);
  border: 1px solid var(--border);
  font-size: 0.95rem;
  font-weight: 600;
  text-align: left;
  margin-bottom: 1.5rem;
  cursor: pointer;
  align-items: center;
  justify-content: space-between;
}

.article-footer-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

.article-commercial-banner {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border);
  padding: 2rem;
  margin: 3rem 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
}

.banner-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.4rem;
}

.banner-desc {
  font-size: 0.9rem;
  color: var(--text-body);
  margin-bottom: 0;
}

/* ==================================================
   分类归档页面规范
   ================================================== */
.category-page {
  padding-top: 3rem;
  padding-bottom: 5rem;
}

.category-hero {
  border-bottom: 1px solid var(--border);
  padding-bottom: 2.5rem;
  margin-bottom: 3rem;
}

.category-articles-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.category-article-card {
  background-color: var(--bg-white);
  border: 1px solid var(--border);
  padding: 2rem 2.25rem;
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.category-article-card:hover {
  border-color: var(--mist-blue);
  background-color: #FDFAF6;
}

.category-card-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 0.75rem;
}

.category-card-title {
  font-size: 1.45rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.category-card-desc {
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--text-body);
  margin-bottom: 1.25rem;
}

.category-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-light);
  padding-top: 1rem;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

/* ==================================================
   页脚规范 (全面内容目录式)
   ================================================== */
.site-footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding-top: 4.5rem;
  padding-bottom: 3.5rem;
  font-size: 0.875rem;
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 3.5rem;
}

.footer-brand h4 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.footer-brand p {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.75;
  max-width: 320px;
}

.footer-col h5 {
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--text-main);
  margin-bottom: 1.25rem;
}

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

.footer-link {
  color: var(--text-body);
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 2rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.footer-disclaimer {
  max-width: 760px;
  font-size: 0.775rem;
  line-height: 1.6;
  color: var(--text-muted);
  margin-top: 0.75rem;
}

/* ==================================================
   媒体查询与响应式适配
   ================================================== */
@media (max-width: 1024px) {
  .header-nav {
    display: none;
  }
  .menu-toggle {
    display: inline-block;
  }
  .hero-index-columns {
    grid-template-columns: 1fr;
    gap: 0;
  }
  .price-row {
    grid-template-columns: 60px 120px 110px 1fr 120px 120px;
    padding: 1.25rem 0.75rem;
  }
  .review-feature-box {
    grid-template-columns: 1fr;
    gap: 2rem;
    padding: 2rem;
  }
  .article-layout {
    grid-template-columns: 1fr;
  }
  .article-sidebar {
    display: none;
  }
  .mobile-toc-toggle {
    display: flex;
  }
  .mobile-toc-content {
    display: none;
    margin-bottom: 2rem;
  }
  .mobile-toc-content.is-open {
    display: block;
  }
  .footer-top {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .hero-meta-bar {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
  }
  .hero-index-item {
    grid-template-columns: 32px 90px 1fr 24px;
    height: 56px;
  }
  /* 价格目录移动端适配为紧凑行 */
  .price-row {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.65rem;
    padding: 1.25rem 1rem;
  }
  .price-row-cost {
    text-align: left;
    padding-right: 0;
  }
  .price-row-cta {
    width: 100%;
  }
  .price-row-cta .btn {
    width: 100%;
  }
  .device-dossier {
    padding: 1.5rem;
  }
  .dossier-grid-two-col,
  .dossier-notes-layout {
    grid-template-columns: 1fr;
  }
  .directory-table {
    display: block;
    overflow-x: auto;
  }
  .trouble-row {
    grid-template-columns: 1fr;
    gap: 0.5rem;
  }
  .article-index-row {
    grid-template-columns: 50px 1fr 80px;
    gap: 0.5rem;
    padding: 1rem 0.5rem;
  }
  .article-row-readtime,
  .article-row-action {
    display: none;
  }
  .article-content {
    padding: 1.5rem 1.25rem;
  }
  .footer-top {
    grid-template-columns: 1fr;
  }
}