/* ==========================================================================
   山水云机场 · 第1套完整独立中文网站
   视觉主题：山阶层序系统 (Mountain Terrace Hierarchy System)
   技术规范：原生 CSS3 · 响应式移动优先 · 零框架依赖
   ========================================================================== */

:root {
  /* 15. 主配色规范 */
  --bg: #F8FAF8;
  --surface: #FFFFFF;
  --surface-alt: #EFF2EF;
  --text: #1F2728;
  --body-text: #5D6667;
  --muted: #899193;
  --mountain: #48636A;
  --mountain-dark: #365159;
  --green: #5E7368;
  --green-dark: #4A5D54;
  --warm: #A5805D;
  --accent: #AF7053;
  --tint-mountain: #EEF2F1;
  --tint-green: #EEF2EF;
  --tint-warm: #F6EFE8;
  --border: #DDE2DE;
  --footer-text: #4B5557;

  /* 字体与排版 */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  --max-width: 1220px;
  --article-max-width: 800px;
  --header-height: 70px;
  --shadow-subtle: 0 10px 28px rgba(31, 39, 40, 0.025);
  --radius-sm: 4px;
  --radius-md: 6px;
  --transition-fast: 180ms 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);
  font-size: 16.5px;
  line-height: 1.8;
  color: var(--body-text);
  background-color: var(--bg);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--text);
  font-weight: 600;
  line-height: 1.32;
  letter-spacing: -0.01em;
}

h1 {
  font-size: clamp(28px, 4.2vw, 48px);
}

h2 {
  font-size: clamp(24px, 3vw, 34px);
}

h3 {
  font-size: clamp(19px, 2.2vw, 23px);
}

p {
  margin-bottom: 1rem;
}

p:last-child {
  margin-bottom: 0;
}

a {
  color: var(--mountain);
  text-decoration: none;
  transition: color var(--transition-fast), border-color var(--transition-fast), background-color var(--transition-fast);
}

a:hover {
  color: var(--mountain-dark);
}

ul, ol {
  list-style: none;
}

/* 258. Focus状态：清晰可访问 */
a:focus-visible,
button:focus-visible,
summary:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--mountain);
  outline-offset: 3px;
  border-radius: 2px;
}

/* 通用容器 */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: 24px;
}

/* 辅助跳转链接 */
.skip-link {
  position: absolute;
  top: -100px;
  left: 16px;
  background: var(--mountain-dark);
  color: var(--surface);
  padding: 8px 16px;
  z-index: 1000;
  font-size: 14px;
  border-radius: var(--radius-sm);
}

.skip-link:focus {
  top: 12px;
}

/* ==========================================================================
   24-27. Header 导航栏 (66px-72px)
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 200;
  height: var(--header-height);
  background-color: var(--surface);
  border-bottom: 1px solid var(--border);
}

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

.brand-link {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--text);
  flex-shrink: 0;
}

.brand-link:hover {
  color: var(--text);
}

.brand-logo {
  width: 38px;
  height: 32px;
  flex-shrink: 0;
  display: block;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.brand-name {
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: 0.02em;
}

.brand-sub {
  font-size: 11.5px;
  color: var(--muted);
  margin-top: 2px;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 18px;
}

.nav-link {
  position: relative;
  font-size: 14.5px;
  color: var(--body-text);
  padding: 6px 2px;
  font-weight: 500;
  white-space: nowrap;
}

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

.nav-link.active::after,
.nav-link:hover::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 22px;
  height: 2px;
  background-color: var(--mountain);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

/* 按钮体系 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-family: inherit;
  font-size: 14.5px;
  font-weight: 600;
  line-height: 1.4;
  padding: 9px 18px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  transition: background-color var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast);
  white-space: nowrap;
}

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

.btn:hover .btn-arrow,
.terrace-link:hover .btn-arrow,
.text-link:hover .btn-arrow {
  transform: translateX(3px);
}

.btn-primary {
  background-color: var(--mountain);
  color: var(--surface);
  border-color: var(--mountain);
}

.btn-primary:hover {
  background-color: var(--mountain-dark);
  border-color: var(--mountain-dark);
  color: var(--surface);
}

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

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

.btn-green {
  background-color: var(--green);
  color: var(--surface);
  border-color: var(--green);
}

.btn-green:hover {
  background-color: var(--green-dark);
  border-color: var(--green-dark);
  color: var(--surface);
}

.btn-sm {
  font-size: 13.5px;
  padding: 7px 14px;
}

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--mountain);
  border-bottom: 1px solid transparent;
}

.text-link:hover {
  color: var(--mountain-dark);
  border-bottom-color: var(--mountain-dark);
}

/* 移动端菜单按钮与抽屉 */
.mobile-menu-toggle {
  display: none;
  align-items: center;
  gap: 6px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  font-family: inherit;
  font-size: 14px;
  font-weight: 600;
  padding: 7px 14px;
  border-radius: var(--radius-sm);
  cursor: pointer;
}

.mobile-menu-toggle:hover {
  background-color: var(--tint-mountain);
}

.mobile-nav-drawer {
  display: none;
  background-color: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 16px 24px 20px;
}

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

.mobile-nav-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px 16px;
  margin-bottom: 16px;
}

.mobile-nav-list a {
  display: block;
  padding: 8px 10px;
  font-size: 15px;
  color: var(--text);
  border-left: 2px solid var(--border);
  background-color: var(--bg);
}

.mobile-nav-list a:hover,
.mobile-nav-list a.active {
  border-left-color: var(--mountain);
  background-color: var(--tint-mountain);
  font-weight: 600;
}

/* ==========================================================================
   28-46. Hero 三阶主视觉 (Desktop 650px-760px)
   ========================================================================== */
.hero-section {
  background-color: var(--surface);
  border-bottom: 1px solid var(--border);
  padding-top: 34px;
  padding-bottom: 38px;
  min-height: 670px;
  max-height: 755px;
  display: flex;
  align-items: center;
}

.hero-container {
  width: 100%;
}

.hero-top {
  max-width: 920px;
  margin-bottom: 24px;
}

.hero-meta-row {
  display: flex;
  align-items: center;
   flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 10px;
}

.hero-badge {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  color: var(--mountain);
  background-color: var(--tint-mountain);
  padding: 3px 10px;
  border-left: 3px solid var(--mountain);
}

.hero-brand-tag {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--warm);
  letter-spacing: 0.04em;
}

.hero-slogan {
  font-size: clamp(17px, 2vw, 20px);
  font-weight: 600;
  color: var(--green-dark);
  line-height: 1.45;
  margin-bottom: 8px;
}

.hero-title {
  font-size: clamp(28px, 3.6vw, 46px);
  line-height: 1.22;
  color: var(--text);
  margin-bottom: 10px;
}

.hero-desc {
  font-size: 16px;
  line-height: 1.72;
  color: var(--body-text);
  max-width: 820px;
  margin-bottom: 16px;
}

.hero-cta-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 14px 20px;
}

/* 三阶主视觉容器 */
.hero-terraces {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 18px;
}

.hero-terrace {
  display: grid;
  grid-template-columns: 155px 1fr auto;
  align-items: center;
  gap: 20px;
  min-height: 94px;
  max-height: 116px;
  padding: 16px 24px;
  border-top: 1px solid var(--border);
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-subtle);
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.hero-terrace:hover {
  transform: translateX(2px);
  border-color: var(--mountain);
}

/* 37-38. Hero阶层宽度与缩进 (纯布局视觉，不映射数据比例) */
.hero-terrace--step1 {
  width: 92%;
  margin-inline-start: 0;
  background-color: var(--bg);
  border-left: 3px solid var(--mountain);
}

.hero-terrace--step2 {
  width: 81%;
  margin-inline-start: 84px;
  background-color: var(--tint-green);
  border-left: 3px solid var(--green);
}

.hero-terrace--step3 {
  width: 68%;
  margin-inline-start: 168px;
  background-color: var(--tint-warm);
  border-left: 3px solid var(--warm);
}

.terrace-head {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.terrace-step-num {
  font-size: 12.5px;
  font-weight: 700;
  color: var(--muted);
  letter-spacing: 0.06em;
}

.terrace-step-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
}

.terrace-body {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.terrace-tags {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 14px;
}

.terrace-tag {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  padding: 2px 10px;
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: 2px;
}

.terrace-subinfo {
  font-size: 13.5px;
  color: var(--body-text);
}

.terrace-link {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 14px;
  font-weight: 600;
  color: var(--mountain);
  white-space: nowrap;
}

/* ==========================================================================
   48. Section 统一山阶层序结构
   ========================================================================== */
.section-block {
  padding-block: 68px;
  border-bottom: 1px solid var(--border);
}

.section-block--white {
  background-color: var(--surface);
}

.section-block--alt {
  background-color: var(--surface-alt);
}

.section-header {
  max-width: 840px;
  margin-bottom: 36px;
}

.section-index {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  font-weight: 700;
  color: var(--mountain);
  letter-spacing: 0.05em;
  margin-bottom: 10px;
}

.section-index::before {
  content: "";
  display: inline-block;
  width: 24px;
  height: 2px;
  background-color: var(--mountain);
}

.section-title {
  margin-bottom: 14px;
}

.section-lead {
  font-size: 17px;
  color: var(--text);
  font-weight: 500;
  line-height: 1.78;
  margin-bottom: 10px;
}

.section-note {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.65;
  padding-left: 12px;
  border-left: 2px solid var(--warm);
}

/* ==========================================================================
   49-63. 01 / 套餐阶 (五阶方案，山峰式横向缩进节奏)
   ========================================================================== */
.plan-terraces {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 36px;
}

.plan-terrace {
  display: grid;
  grid-template-columns: 170px 140px 140px 1fr auto;
  align-items: center;
  gap: 18px;
  padding: 20px 26px;
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--mountain);
  border-radius: var(--radius-sm);
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.plan-terrace:hover {
  transform: translateX(2px);
  border-color: var(--mountain);
}

/* 58-59. 五阶视觉节奏（左起 -> 右缩 -> 视觉中心 -> 回缩 -> 较左） */
.plan-terrace--t1 {
  width: 82%;
  margin-inline-start: 0;
}

.plan-terrace--t2 {
  width: 85%;
  margin-inline-start: 5%;
}

/* 60. 主力方案唯一突出 */
.plan-terrace--t3 {
  width: 88%;
  margin-inline-start: 10%;
  background-color: var(--tint-green);
  border-color: var(--green);
  border-left: 3px solid var(--green);
  padding-block: 24px;
}

.plan-terrace--t4 {
  width: 84%;
  margin-inline-start: 6%;
}

.plan-terrace--t5 {
  width: 78%;
  margin-inline-start: 2%;
}

.plan-name-wrap {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.plan-step-code {
  font-size: 13px;
  font-weight: 700;
  color: var(--muted);
}

.plan-name-row {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.plan-name {
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
}

.plan-badge {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  color: var(--surface);
  background-color: var(--accent);
  padding: 2px 8px;
  border-radius: 2px;
}

.plan-price {
  font-size: 30px;
  font-weight: 700;
  color: var(--text);
  line-height: 1.2;
}

.plan-terrace--t3 .plan-price {
  font-size: 34px;
  color: var(--green-dark);
}

.plan-price small {
  font-size: 14px;
  font-weight: 500;
  color: var(--muted);
}

.plan-quota {
  font-size: 17px;
  font-weight: 600;
  color: var(--mountain-dark);
}

.plan-fit {
  font-size: 15px;
  color: var(--body-text);
}

.plan-fit strong {
  color: var(--text);
  font-weight: 600;
}

/* 62. 流量判断补充阶层 */
.quota-guide-tier {
  width: 90%;
  margin-inline-start: 4%;
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--warm);
  padding: 24px 28px;
  border-radius: var(--radius-sm);
}

.quota-guide-tier h3 {
  font-size: 20px;
  margin-bottom: 12px;
}

.quota-factors {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 16px;
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px solid var(--border);
}

.quota-factor-item strong {
  display: block;
  font-size: 15px;
  color: var(--text);
  margin-bottom: 4px;
}

.quota-factor-item p {
  font-size: 13.5px;
  color: var(--body-text);
  line-height: 1.6;
}

/* ==========================================================================
   64-73. 02 / 节点阶 (四层宽条：香港最宽 -> 日本略缩 -> 新加坡继续缩 -> 美国重新展开)
   ========================================================================== */
.node-terraces {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.node-terrace {
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-left: 3px solid var(--mountain);
  padding: 24px 28px;
  border-radius: var(--radius-sm);
  transition: border-color var(--transition-fast), transform var(--transition-fast);
}

.node-terrace:hover {
  border-color: var(--mountain);
  transform: translateX(2px);
}

.node-terrace--hk {
  width: 96%;
  margin-inline-start: 0;
}

.node-terrace--jp {
  width: 88%;
  margin-inline-start: 4%;
  border-left-color: var(--green);
}

.node-terrace--sg {
  width: 80%;
  margin-inline-start: 8%;
  border-left-color: var(--warm);
}

.node-terrace--us {
  width: 91%;
  margin-inline-start: 2%;
  border-left-color: var(--mountain-dark);
}

.node-terrace-top {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 12px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}

.node-region-title {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.node-region-num {
  font-size: 14px;
  font-weight: 700;
  color: var(--mountain);
}

.node-region-name {
  font-size: 22px;
  font-weight: 700;
  color: var(--text);
}

.node-summary {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 14px;
}

.node-details-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 12px;
}

.node-detail-col {
  font-size: 14.5px;
  line-height: 1.68;
}

.node-detail-label {
  display: block;
  font-size: 13px;
  font-weight: 700;
  color: var(--muted);
  margin-bottom: 3px;
}

.node-reading-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px 16px;
  font-size: 14px;
  padding-top: 8px;
  border-top: 1px dashed var(--border);
}

.node-reading-label {
  color: var(--muted);
  font-weight: 600;
}

/* ==========================================================================
   74-87. 03 / 线路阶 (三层理解递进 + HTML横线表格 + 5个扩展问答)
   ========================================================================== */
.line-terraces {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 36px;
}

.line-terrace {
  background-color: var(--surface);
  border: 1px solid var(--border);
  padding: 24px 28px;
  border-radius: var(--radius-sm);
}

.line-terrace--l1 {
  width: 95%;
  margin-inline-start: 0;
  border-left: 3px solid var(--mountain);
}

.line-terrace--l2 {
  width: 89%;
  margin-inline-start: 4%;
  border-left: 3px solid var(--green);
}

.line-terrace--l3 {
  width: 83%;
  margin-inline-start: 8%;
  border-left: 3px solid var(--warm);
}

.line-terrace-header {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 14px;
}

.line-layer-tag {
  font-size: 13px;
  font-weight: 700;
  color: var(--surface);
  background-color: var(--mountain);
  padding: 2px 9px;
  border-radius: 2px;
}

.line-terrace--l2 .line-layer-tag {
  background-color: var(--green);
}

.line-terrace--l3 .line-layer-tag {
  background-color: var(--warm);
}

.line-split-pair {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--border);
}

.line-subitem h4 {
  font-size: 18px;
  color: var(--text);
  margin-bottom: 6px;
}

.line-subitem p {
  font-size: 15px;
  line-height: 1.72;
}

/* 83-85. HTML线路对比表 (仅横向细线，表头浅灰) */
.table-terrace-wrap {
  width: 92%;
  margin-inline-start: 2%;
  background-color: var(--surface);
  border: 1px solid var(--border);
  padding: 24px 28px;
  margin-bottom: 32px;
  border-radius: var(--radius-sm);
}

.table-caption-title {
  font-size: 19px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 14px;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 15px;
}

.data-table thead th {
  background-color: var(--tint-mountain);
  color: var(--text);
  font-weight: 700;
  padding: 13px 16px;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.data-table tbody td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
  color: var(--body-text);
  vertical-align: top;
  line-height: 1.65;
}

.data-table tbody td:first-child {
  font-weight: 700;
  color: var(--text);
  white-space: nowrap;
}

/* 86. 线路扩展问题层 */
.line-qa-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.line-qa-item {
  background-color: var(--surface);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  border-left: 3px solid var(--mountain);
  padding: 16px 22px;
}

.line-qa-item:nth-child(2) { margin-inline-start: 2%; }
.line-qa-item:nth-child(3) { margin-inline-start: 4%; }
.line-qa-item:nth-child(4) { margin-inline-start: 6%; }
.line-qa-item:nth-child(5) { margin-inline-start: 8%; }

.line-qa-item h3 {
  font-size: 17.5px;
  margin-bottom: 6px;
}

.line-qa-item p {
  font-size: 15px;
}

/* ==========================================================================
   88-101. 04 / AI工具 & 05 / 流媒体 (三层横向信息阶，纯文字无Logo墙)
   ========================================================================== */
.info-terraces {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.info-terrace {
  display: grid;
  grid-template-columns: 230px 210px 1fr auto;
  align-items: center;
  gap: 22px;
  padding: 24px 28px;
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-left: 3px solid var(--mountain);
  border-radius: var(--radius-sm);
}

.info-terrace--step1 {
  width: 94%;
  margin-inline-start: 0;
}

.info-terrace--step2 {
  width: 86%;
  margin-inline-start: 5%;
  border-left-color: var(--green);
}

.info-terrace--step3 {
  width: 78%;
  margin-inline-start: 10%;
  border-left-color: var(--warm);
}

.info-theme-label {
  font-size: 12.5px;
  font-weight: 700;
  color: var(--muted);
  display: block;
  margin-bottom: 4px;
}

.info-theme-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
}

.info-platforms {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.platform-pill {
  font-size: 14.5px;
  font-weight: 600;
  color: var(--text);
  background-color: var(--surface);
  border: 1px solid var(--border);
  padding: 4px 12px;
  border-radius: 2px;
}

.info-focus {
  font-size: 15px;
  line-height: 1.7;
  color: var(--body-text);
}

/* 99. 流媒体视觉：平台类型作为大标题，宽度递进 */
.stream-terraces {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.stream-terrace {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-top: 2px solid var(--mountain);
  padding: 26px 30px;
  border-radius: var(--radius-sm);
}

.stream-terrace--s1 {
  width: 95%;
  margin-inline-start: 0;
}

.stream-terrace--s2 {
  width: 85%;
  margin-inline-start: 6%;
  border-top-color: var(--green);
}

.stream-terrace--s3 {
  width: 76%;
  margin-inline-start: 12%;
  border-top-color: var(--warm);
}

.stream-head-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 12px;
}

.stream-big-type {
  font-size: 26px;
  font-weight: 700;
  color: var(--text);
}

.stream-platforms-text {
  font-size: 17px;
  font-weight: 700;
  color: var(--mountain);
}

/* ==========================================================================
   102-110. 06 / 客户端 (桌面端 ↓ 移动端 ↓ 通用操作)
   ========================================================================== */
.client-terraces {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.client-terrace {
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-left: 3px solid var(--mountain);
  padding: 26px 30px;
  border-radius: var(--radius-sm);
}

.client-terrace--desktop {
  width: 96%;
  margin-inline-start: 0;
}

.client-terrace--mobile {
  width: 88%;
  margin-inline-start: 5%;
  border-left-color: var(--green);
}

.client-terrace--common {
  width: 80%;
  margin-inline-start: 10%;
  border-left-color: var(--warm);
  background-color: var(--tint-warm);
}

.client-tier-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}

.client-os-pair {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.client-os-block h4 {
  font-size: 19px;
  color: var(--text);
  margin-bottom: 8px;
}

.client-key-points {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 10px;
  margin-top: 10px;
}

.client-key-tag {
  font-size: 13px;
  font-weight: 600;
  color: var(--mountain-dark);
  background-color: var(--surface);
  border: 1px solid var(--border);
  padding: 2px 9px;
}

/* ==========================================================================
   111-125. 07 / 完整价格 (五阶价目：普通110-150px，主力140-180px)
   ========================================================================== */
.price-schedule {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.price-band {
  display: grid;
  grid-template-columns: 72px 170px 140px 160px 1fr auto;
  align-items: center;
  gap: 18px;
  min-height: 118px;
  max-height: 146px;
  padding: 20px 28px;
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--mountain);
  border-radius: var(--radius-sm);
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.price-band:hover {
  transform: translateX(2px);
  border-color: var(--mountain);
}

.price-band--p1 {
  width: 80%;
  margin-inline-start: 0;
}

.price-band--p2 {
  width: 84%;
  margin-inline-start: 6%;
}

/* 120-121. 主力方案唯一突出 (140px-180px) */
.price-band--p3 {
  width: 90%;
  margin-inline-start: 10%;
  min-height: 148px;
  max-height: 176px;
  background-color: var(--tint-green);
  border-color: var(--green);
  border-left: 3px solid var(--green);
}

.price-band--p4 {
  width: 85%;
  margin-inline-start: 5%;
}

.price-band--p5 {
  width: 78%;
  margin-inline-start: 2%;
}

.price-num-large {
  font-size: 38px;
  font-weight: 700;
  color: var(--muted);
  line-height: 1;
}

.price-band--p3 .price-num-large {
  font-size: 46px;
  color: var(--green);
}

.price-band-amount {
  font-size: 32px;
  font-weight: 700;
  color: var(--text);
}

.price-band--p3 .price-band-amount {
  font-size: 38px;
  color: var(--green-dark);
}

/* ==========================================================================
   126-133. 08 / 山水云机场深度评测 (山阶评测导览)
   ========================================================================== */
.review-showcase {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.review-tier-conclusion {
  width: 96%;
  margin-inline-start: 0;
  background-color: var(--tint-mountain);
  border: 1px solid var(--border);
  border-left: 3px solid var(--mountain);
  padding: 26px 30px;
}

.review-tier-dims {
  width: 88%;
  margin-inline-start: 5%;
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-left: 3px solid var(--green);
  padding: 26px 30px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.review-tier-action {
  width: 80%;
  margin-inline-start: 10%;
  background-color: var(--tint-warm);
  border: 1px solid var(--border);
  border-left: 3px solid var(--warm);
  padding: 22px 30px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

/* ==========================================================================
   134-144. 09 / 使用教程 (“内容山阶” 4层结构，非九宫格)
   ========================================================================== */
.guide-mountain {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.guide-tier {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--mountain);
  padding: 24px 28px;
  border-radius: var(--radius-sm);
}

.guide-tier--t1 {
  width: 96%;
  margin-inline-start: 0;
  background-color: var(--tint-green);
  border-left-color: var(--green);
}

.guide-tier--t2 {
  width: 90%;
  margin-inline-start: 4%;
}

.guide-tier--t3 {
  width: 84%;
  margin-inline-start: 8%;
  border-left-color: var(--warm);
}

.guide-tier--t4 {
  width: 78%;
  margin-inline-start: 12%;
  border-left-color: var(--mountain-dark);
}

.guide-tier-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.guide-tier-label {
  font-size: 13.5px;
  font-weight: 700;
  color: var(--mountain);
}

.guide-entries {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.guide-entry {
  padding-bottom: 16px;
  border-bottom: 1px dashed var(--border);
}

.guide-entry:last-child {
  padding-bottom: 0;
  border-bottom: none;
}

.guide-meta-top {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 6px;
}

.guide-cat-tag {
  font-weight: 700;
  color: var(--mountain-dark);
  background-color: var(--surface);
  border: 1px solid var(--border);
  padding: 1px 8px;
}

.guide-entry-title {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 6px;
}

.guide-entry-title a {
  color: var(--text);
}

.guide-entry-title a:hover {
  color: var(--mountain);
}

.guide-entry-desc {
  font-size: 15px;
  color: var(--body-text);
  margin-bottom: 10px;
}

.category-hub-bar {
  margin-top: 28px;
  padding: 20px 26px;
  background-color: var(--surface);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 14px;
}

.category-hub-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ==========================================================================
   151-164. 10 / 网络排障 (7条逐级缩进检查层，无箭头无流程图)
   ========================================================================== */
.trouble-layers {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.trouble-layer {
  display: grid;
  grid-template-columns: 64px 150px 1fr 1.2fr;
  align-items: baseline;
  gap: 18px;
  padding: 18px 24px;
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-left: 3px solid var(--mountain);
}

.trouble-layer--s1 { width: 82%; margin-inline-start: 0; }
.trouble-layer--s2 { width: 82%; margin-inline-start: 3%; }
.trouble-layer--s3 { width: 82%; margin-inline-start: 6%; border-left-color: var(--green); }
.trouble-layer--s4 { width: 82%; margin-inline-start: 9%; border-left-color: var(--green); }
.trouble-layer--s5 { width: 82%; margin-inline-start: 12%; border-left-color: var(--warm); }
.trouble-layer--s6 { width: 82%; margin-inline-start: 15%; border-left-color: var(--warm); }
.trouble-layer--s7 { width: 82%; margin-inline-start: 18%; border-left-color: var(--accent); }

.trouble-num {
  font-size: 22px;
  font-weight: 700;
  color: var(--mountain);
}

.trouble-target {
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
}

.trouble-symptom,
.trouble-advice {
  font-size: 14.5px;
  line-height: 1.68;
}

.trouble-field-label {
  display: block;
  font-size: 12.5px;
  font-weight: 700;
  color: var(--muted);
  margin-bottom: 2px;
}

/* ==========================================================================
   165-171. 11 / 常见问题 (“问答层序” 6大分组，连续问题行)
   ========================================================================== */
.faq-groups {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.faq-group {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--mountain);
  padding: 22px 28px;
}

.faq-group:nth-child(2) { margin-inline-start: 2%; border-left-color: var(--green); }
.faq-group:nth-child(3) { margin-inline-start: 4%; border-left-color: var(--warm); }
.faq-group:nth-child(4) { margin-inline-start: 6%; border-left-color: var(--mountain-dark); }
.faq-group:nth-child(5) { margin-inline-start: 3%; border-left-color: var(--green-dark); }
.faq-group:nth-child(6) { margin-inline-start: 0; border-left-color: var(--accent); }

.faq-group-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
  padding-bottom: 12px;
  margin-bottom: 6px;
  border-bottom: 2px solid var(--border);
}

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

.faq-item:last-child {
  border-bottom: none;
}

.faq-question {
  width: 100%;
  display: grid;
  grid-template-columns: 52px 1fr 28px;
  align-items: center;
  gap: 12px;
  padding: 15px 4px;
  background: none;
  border: none;
  text-align: left;
  font-family: inherit;
  cursor: pointer;
  color: var(--text);
}

.faq-question:hover .faq-q-text {
  color: var(--mountain);
}

.faq-q-code {
  font-size: 14px;
  font-weight: 700;
  color: var(--mountain);
}

.faq-q-text {
  font-size: 16.5px;
  font-weight: 600;
  color: var(--text);
  line-height: 1.45;
}

.faq-q-icon {
  font-size: 18px;
  font-weight: 600;
  color: var(--muted);
  text-align: right;
}

.faq-answer {
  padding: 0 32px 16px 64px;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--body-text);
}

/* JS启用时折叠未展开的FAQ答案；无JS时默认全部可见 */
.js-enabled .faq-item:not(.is-open) .faq-answer {
  display: none;
}

/* FAQ底部转化横阶 */
.cta-bottom-terrace {
  margin-top: 38px;
  background-color: var(--tint-green);
  border: 1px solid var(--green);
  border-left: 4px solid var(--green);
  padding: 26px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}

/* ==========================================================================
   145-150. 分类页面样式 (简化山阶Hero 220px-320px + 核心专题 + 纵向列表)
   ========================================================================== */
.cat-hero {
  background-color: var(--surface);
  border-bottom: 1px solid var(--border);
  min-height: 230px;
  max-height: 310px;
  padding-block: 32px;
  display: flex;
  align-items: center;
}

.breadcrumb-nav {
  font-size: 13.5px;
  color: var(--muted);
  margin-bottom: 14px;
}

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

.breadcrumb-list a {
  color: var(--body-text);
}

.breadcrumb-list a:hover {
  color: var(--mountain);
}

.cat-hero-terrace {
  width: 92%;
  border-left: 3px solid var(--mountain);
  padding-left: 20px;
}

.cat-hero-title {
  font-size: clamp(26px, 3.4vw, 38px);
  margin-bottom: 10px;
}

.cat-hero-desc {
  font-size: 16px;
  color: var(--body-text);
  max-width: 820px;
}

.cat-core-topic {
  width: 90%;
  margin-inline-start: 3%;
  background-color: var(--tint-green);
  border: 1px solid var(--border);
  border-left: 3px solid var(--green);
  padding: 24px 28px;
  margin-bottom: 32px;
}

.cat-article-list {
  width: 86%;
  margin-inline-start: 6%;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.cat-article-item {
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--mountain);
  padding: 24px 28px;
}

/* ==========================================================================
   172-183. 文章页面样式 (正文最大宽760px-820px + 右侧轻量目录220px-240px)
   ========================================================================== */
.article-page-wrap {
  padding-block: 42px 72px;
}

.article-layout {
  display: grid;
  grid-template-columns: minmax(0, 800px) 230px;
  justify-content: space-between;
  align-items: start;
  gap: 36px;
}

.article-main {
  background-color: var(--surface);
  border: 1px solid var(--border);
  padding: 40px 44px;
  max-width: var(--article-max-width);
}

.article-header {
  border-bottom: 1px solid var(--border);
  padding-bottom: 24px;
  margin-bottom: 28px;
}

.article-cat-badge {
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  color: var(--mountain);
  background-color: var(--tint-mountain);
  padding: 3px 10px;
  border-left: 3px solid var(--mountain);
  margin-bottom: 12px;
}

.article-title {
  font-size: clamp(26px, 3.2vw, 38px);
  line-height: 1.28;
  margin-bottom: 14px;
}

.article-summary {
  font-size: 16.5px;
  color: var(--body-text);
  line-height: 1.75;
  margin-bottom: 16px;
}

.article-meta-bar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px 20px;
  font-size: 13.5px;
  color: var(--muted);
}

/* 174. 文章顶部3层阅读结构 */
.article-reading-steps {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-top: 18px;
  padding-top: 16px;
  border-top: 1px dashed var(--border);
}

.reading-step-row {
  font-size: 13.5px;
  color: var(--body-text);
  background-color: var(--bg);
  border-left: 2px solid var(--mountain);
  padding: 5px 12px;
}

.reading-step-row:nth-child(1) { width: 94%; margin-inline-start: 0; }
.reading-step-row:nth-child(2) { width: 86%; margin-inline-start: 4%; border-left-color: var(--green); }
.reading-step-row:nth-child(3) { width: 78%; margin-inline-start: 8%; border-left-color: var(--warm); }

/* 175. 快速结论模块 */
.fast-conclusion {
  background-color: var(--tint-green);
  border: 1px solid var(--border);
  border-left: 4px solid var(--green);
  padding: 22px 26px;
  margin-bottom: 32px;
}

.fast-conclusion-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--green-dark);
  margin-bottom: 8px;
}

.fast-conclusion p {
  font-size: 16px;
  color: var(--text);
  font-weight: 500;
}

/* 181. 文章内部章节层序 */
.article-content h2 {
  font-size: 24px;
  color: var(--text);
  margin-top: 38px;
  margin-bottom: 14px;
  padding-left: 14px;
  border-left: 3px solid var(--mountain);
}

.article-content h3 {
  font-size: 19px;
  color: var(--text);
  margin-top: 24px;
  margin-bottom: 10px;
}

.article-content p {
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--body-text);
  margin-bottom: 16px;
}

.article-content ul,
.article-content ol {
  margin-bottom: 18px;
  padding-left: 20px;
}

.article-content ul li {
  list-style: disc;
  margin-bottom: 8px;
  line-height: 1.78;
}

.article-content ol li {
  list-style: decimal;
  margin-bottom: 8px;
  line-height: 1.78;
}

.article-callout {
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-left: 3px solid var(--warm);
  padding: 18px 22px;
  margin-block: 20px;
}

.article-callout-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 6px;
}

/* 179-180. 本文目录 (Desktop 220-240px，Mobile折叠) */
.article-toc-aside {
  position: sticky;
  top: 90px;
  width: 230px;
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--mountain);
  padding: 18px 20px;
}

.toc-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

.toc-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  max-height: calc(100vh - 180px);
  overflow-y: auto;
}

.toc-list a {
  display: block;
  font-size: 13.5px;
  line-height: 1.45;
  color: var(--body-text);
  padding-left: 8px;
  border-left: 2px solid transparent;
}

.toc-list a:hover,
.toc-list a.active {
  color: var(--mountain);
  border-left-color: var(--mountain);
  font-weight: 600;
}

.mobile-toc-details {
  display: none;
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-left: 3px solid var(--mountain);
  padding: 14px 18px;
  margin-bottom: 24px;
}

.mobile-toc-details summary {
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
  cursor: pointer;
}

.mobile-toc-details .toc-list {
  margin-top: 12px;
  max-height: none;
}

/* 文章底部相关阅读与上下篇导航 */
.article-related-box {
  margin-top: 40px;
  padding-top: 28px;
  border-top: 1px solid var(--border);
}

.related-links-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 14px;
}

.related-link-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background-color: var(--bg);
  border: 1px solid var(--border);
  border-left: 3px solid var(--mountain);
}

.article-pager {
  margin-top: 28px;
  padding-top: 22px;
  border-top: 1px solid var(--border);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 16px;
  align-items: center;
}

.pager-link {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 12px 16px;
  background-color: var(--bg);
  border: 1px solid var(--border);
}

.pager-link--next {
  text-align: right;
}

.pager-label {
  font-size: 12.5px;
  color: var(--muted);
  font-weight: 600;
}

.pager-title {
  font-size: 14.5px;
  font-weight: 600;
  color: var(--text);
}

/* ==========================================================================
   212-219. Footer (浅山灰 #EFF2EF，Desktop高度 250px-320px)
   ========================================================================== */
.site-footer {
  background-color: var(--surface-alt);
  color: var(--footer-text);
  border-top: 1px solid var(--border);
  padding-block: 34px 24px;
  min-height: 255px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr 0.9fr;
  gap: 24px;
  padding-bottom: 22px;
  border-bottom: 1px solid var(--border);
}

.footer-brand-desc {
  font-size: 13.5px;
  color: var(--footer-text);
  margin-block: 10px 14px;
}

.footer-col-title {
  font-size: 14.5px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 10px;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.footer-links a {
  font-size: 13.5px;
  color: var(--footer-text);
}

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

.footer-bottom {
  padding-top: 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  font-size: 13px;
  color: var(--footer-text);
}

.friend-links {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px 16px;
}

.friend-links a {
  color: var(--footer-text);
  font-weight: 500;
}

.friend-links a:hover {
  color: var(--text);
  text-decoration: underline;
}

/* ==========================================================================
   232-242 & 259. 响应式适配 (1440 / 1024 / 768 / 430 / 390 / 375)
   ========================================================================== */
@media (max-width: 1120px) {
  .main-nav {
    gap: 12px;
  }
  .nav-link {
    font-size: 13.5px;
  }
  .hero-terrace--step1 { width: 96%; }
  .hero-terrace--step2 { width: 88%; margin-inline-start: 48px; }
  .hero-terrace--step3 { width: 78%; margin-inline-start: 96px; }

  .plan-terrace,
  .price-band {
    grid-template-columns: 1fr 1fr;
    max-height: none;
  }
  .quota-factors {
    grid-template-columns: repeat(3, 1fr);
  }
  .article-layout {
    grid-template-columns: 1fr;
  }
  .article-toc-aside {
    display: none;
  }
  .mobile-toc-details {
    display: block;
  }
  .article-main {
    max-width: 100%;
  }
}

@media (max-width: 920px) {
  .main-nav,
  .header-actions .btn {
    display: none;
  }
  .mobile-menu-toggle {
    display: inline-flex;
  }
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* 45-46, 63, 85, 125, 233-242. Mobile 山阶适配 (消除大幅缩进，严禁横向溢出) */
@media (max-width: 768px) {
  .container {
    padding-inline: 16px;
  }

  .section-block {
    padding-block: 48px;
  }

  .hero-section {
    min-height: auto;
    max-height: none;
    padding-block: 28px 36px;
  }

  .hero-terrace {
    grid-template-columns: 1fr;
    gap: 10px;
    min-height: auto;
    max-height: none;
    padding: 16px;
    width: auto !important;
  }

  /* 46. Mobile阶差：仅保留4px-14px轻微缩进，严禁超屏 */
  .hero-terrace--step1 { margin-inline-start: 0; }
  .hero-terrace--step2 { margin-inline-start: 6px; }
  .hero-terrace--step3 { margin-inline-start: 12px; }

  /* 63 & 235. Mobile套餐阶顺序：主力 ↓ 日常 ↓ 轻量 ↓ 高频 ↓ 长期 */
  .plan-terrace {
    grid-template-columns: 1fr;
    gap: 10px;
    padding: 18px;
    width: auto !important;
  }
  .plan-terrace--t3 { order: 1; margin-inline-start: 0; }
  .plan-terrace--t2 { order: 2; margin-inline-start: 4px; }
  .plan-terrace--t1 { order: 3; margin-inline-start: 8px; }
  .plan-terrace--t4 { order: 4; margin-inline-start: 4px; }
  .plan-terrace--t5 { order: 5; margin-inline-start: 8px; }

  .quota-guide-tier {
    width: auto;
    margin-inline-start: 0;
    padding: 18px;
  }

  .quota-factors {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  /* 236. Mobile节点纵向 */
  .node-terrace {
    width: auto !important;
    padding: 18px;
  }
  .node-terrace--hk { margin-inline-start: 0; }
  .node-terrace--jp { margin-inline-start: 4px; }
  .node-terrace--sg { margin-inline-start: 8px; }
  .node-terrace--us { margin-inline-start: 4px; }

  .node-details-grid {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  /* 237. Mobile线路与块状表格 */
  .line-terrace,
  .table-terrace-wrap {
    width: auto !important;
    margin-inline-start: 0 !important;
    padding: 18px;
  }

  .line-split-pair {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  /* 85 & 275. 手机表格自动转为一项一组块状布局，避免横向滚动 */
  .data-table,
  .data-table thead,
  .data-table tbody,
  .data-table th,
  .data-table td,
  .data-table tr {
    display: block;
    width: 100%;
  }

  .data-table thead {
    display: none;
  }

  .data-table tbody tr {
    border: 1px solid var(--border);
    border-left: 3px solid var(--mountain);
    margin-bottom: 12px;
    padding: 12px;
    background-color: var(--bg);
  }

  .data-table tbody td {
    border-bottom: none;
    padding: 6px 4px;
    white-space: normal !important;
  }

  .data-table tbody td::before {
    content: attr(data-label) "：";
    font-weight: 700;
    color: var(--text);
  }

  .line-qa-item {
    margin-inline-start: 0 !important;
  }

  /* 238-240. Mobile AI / 流媒体 / 客户端 */
  .info-terrace {
    grid-template-columns: 1fr;
    gap: 12px;
    width: auto !important;
    padding: 18px;
  }
  .info-terrace--step1 { margin-inline-start: 0; }
  .info-terrace--step2 { margin-inline-start: 5px; }
  .info-terrace--step3 { margin-inline-start: 10px; }

  .stream-terrace,
  .client-terrace {
    width: auto !important;
    padding: 18px;
  }
  .stream-terrace--s1, .client-terrace--desktop { margin-inline-start: 0; }
  .stream-terrace--s2, .client-terrace--mobile { margin-inline-start: 5px; }
  .stream-terrace--s3, .client-terrace--common { margin-inline-start: 10px; }

  .client-os-pair {
    grid-template-columns: 1fr;
    gap: 18px;
  }

  /* 125. Mobile完整价格：主力第一，然后日常、轻量、高频、长期 */
  .price-band {
    grid-template-columns: 1fr;
    gap: 8px;
    width: auto !important;
    min-height: auto;
    max-height: none;
    padding: 18px;
  }
  .price-band--p3 { order: 1; margin-inline-start: 0; }
  .price-band--p2 { order: 2; margin-inline-start: 4px; }
  .price-band--p1 { order: 3; margin-inline-start: 8px; }
  .price-band--p4 { order: 4; margin-inline-start: 4px; }
  .price-band--p5 { order: 5; margin-inline-start: 8px; }

  .review-tier-conclusion,
  .review-tier-dims,
  .review-tier-action,
  .guide-tier {
    width: auto !important;
    margin-inline-start: 0 !important;
    padding: 18px;
  }

  .review-tier-dims {
    grid-template-columns: 1fr;
  }

  /* 241. Mobile排障全部单列 */
  .trouble-layer {
    grid-template-columns: 1fr;
    gap: 8px;
    width: auto !important;
    padding: 16px;
  }
  .trouble-layer--s1 { margin-inline-start: 0; }
  .trouble-layer--s2 { margin-inline-start: 2px; }
  .trouble-layer--s3 { margin-inline-start: 4px; }
  .trouble-layer--s4 { margin-inline-start: 6px; }
  .trouble-layer--s5 { margin-inline-start: 8px; }
  .trouble-layer--s6 { margin-inline-start: 10px; }
  .trouble-layer--s7 { margin-inline-start: 12px; }

  /* 171. Mobile FAQ单列 */
  .faq-group {
    margin-inline-start: 0 !important;
    padding: 16px;
  }
  .faq-question {
    grid-template-columns: 42px 1fr 22px;
  }
  .faq-answer {
    padding: 0 8px 14px 12px;
  }

  .cat-hero {
    min-height: auto;
    max-height: none;
  }
  .cat-hero-terrace,
  .cat-core-topic,
  .cat-article-list {
    width: auto !important;
    margin-inline-start: 0 !important;
  }

  .article-main {
    padding: 22px 18px;
  }
  .reading-step-row {
    width: auto !important;
    margin-inline-start: 0 !important;
  }
  .article-pager {
    grid-template-columns: 1fr;
  }
  .pager-link--next {
    text-align: left;
  }

  /* 242. Mobile Footer顺序 */
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 430px) {
  .mobile-nav-list {
    grid-template-columns: 1fr;
  }
  .hero-cta-row {
    flex-direction: column;
    align-items: stretch;
  }
  .hero-cta-row .btn {
    width: 100%;
  }
}

/* ==========================================================================
   231 & 284. prefers-reduced-motion 无障碍动效降级
   ========================================================================== */
@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;
  }
  .hero-terrace:hover,
  .plan-terrace:hover,
  .node-terrace:hover,
  .price-band:hover,
  .btn:hover .btn-arrow,
  .terrace-link:hover .btn-arrow,
  .text-link:hover .btn-arrow {
    transform: none !important;
  }
}