/* ============================================================
   可乐影视 · 整站样式表
   视觉方向：政府信息风（蓝灰配色、明线分隔、高信息密度）
   ============================================================ */

/* ------------------------------------------------------------
   1. Base —— 重置、变量、全局基础
   ------------------------------------------------------------ */
:root {
  --color-primary: #1d4ed8;
  --color-primary-dark: #1e3a8a;
  --color-accent: #d97706;
  --color-bg: #f3f4f6;
  --color-card: #ffffff;
  --color-text: #1f2937;
  --color-text-sub: #6b7280;
  --color-border: #d1d5db;
  --color-border-light: #e5e7eb;
  --color-header-bg: #ffffff;
  --color-footer-bg: #1f2937;
  --color-footer-text: #d1d5db;
  --color-footer-title: #f9fafb;

  --font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  --font-size-body: 15px;
  --font-size-small: 13px;
  --font-size-h1: 24px;
  --font-size-h2: 20px;
  --font-size-h3: 17px;
  --line-height-body: 1.7;

  --container-width: 1200px;
  --container-padding: 16px;
  --radius-card: 8px;
  --radius-tag: 4px;

  --header-height: 64px;
  --transition-fast: 0.2s ease;
}

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

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

body {
  font-family: var(--font-family);
  font-size: var(--font-size-body);
  line-height: var(--line-height-body);
  color: var(--color-text);
  background-color: var(--color-bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

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

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

ul,
ol {
  list-style: none;
}

h1,
h2,
h3,
h4 {
  line-height: 1.4;
  color: var(--color-text);
}

h1 {
  font-size: var(--font-size-h1);
}

h2 {
  font-size: var(--font-size-h2);
}

h3 {
  font-size: var(--font-size-h3);
}

/* 辅助隐藏 */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ------------------------------------------------------------
   2. Layout —— 全站骨架：页头、页脚、主容器
   ------------------------------------------------------------ */

/* 页头 */
.site-header {
  background-color: var(--color-header-bg);
  border-bottom: 2px solid var(--color-primary);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.site-brand {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-primary-dark);
  white-space: nowrap;
  line-height: var(--header-height);
  display: inline-block;
}

.site-brand:hover {
  color: var(--color-primary);
}

.site-nav {
  display: flex;
  align-items: center;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-list a {
  display: inline-block;
  padding: 10px 14px;
  font-size: 15px;
  color: var(--color-text);
  border-radius: var(--radius-tag);
  min-height: 44px;
  line-height: 24px;
}

.nav-list a:hover {
  background-color: var(--color-bg);
  color: var(--color-primary);
}

.nav-list a.is-current {
  color: var(--color-primary);
  font-weight: 600;
  background-color: #eff6ff;
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 10px;
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-tag);
  cursor: pointer;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
}

.nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-text);
}

/* 页脚 */
.site-footer {
  background-color: var(--color-footer-bg);
  color: var(--color-footer-text);
  margin-top: auto;
}

.footer-inner {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 40px var(--container-padding) 24px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

.footer-col h4 {
  color: var(--color-footer-title);
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 12px;
}

.footer-col ul li {
  margin-bottom: 8px;
}

.footer-col ul a {
  color: var(--color-footer-text);
  font-size: 14px;
  line-height: 1.6;
  display: inline-block;
  padding: 4px 0;
  min-height: 24px;
}

.footer-col ul a:hover {
  color: #ffffff;
}

.footer-copy {
  border-top: 1px solid #374151;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 16px var(--container-padding);
  font-size: var(--font-size-small);
  color: #9ca3af;
}

/* 主容器 */
.site-main {
  flex: 1;
}

.home-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.inner-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 24px var(--container-padding) 48px;
}

/* 面包屑 */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: var(--font-size-small);
  color: var(--color-text-sub);
  margin-bottom: 16px;
  padding: 8px 0;
}

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

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

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

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

/* 页面标题区 */
.page-header {
  margin-bottom: 28px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-border-light);
}

.page-title {
  font-size: var(--font-size-h1);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 8px;
}

.page-description {
  font-size: 15px;
  color: var(--color-text-sub);
  max-width: 720px;
}

/* ------------------------------------------------------------
   3. Components —— 通用组件
   ------------------------------------------------------------ */

/* 按钮 */
.btn-primary,
.btn-secondary {
  display: inline-block;
  min-height: 44px;
  padding: 10px 24px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-tag);
  line-height: 24px;
  text-align: center;
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.btn-primary {
  background-color: var(--color-primary);
  color: #ffffff;
  border: 1px solid var(--color-primary);
}

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

.btn-secondary {
  background-color: transparent;
  color: var(--color-primary);
  border: 1px solid var(--color-primary);
}

.btn-secondary:hover {
  background-color: #eff6ff;
  color: var(--color-primary-dark);
}

/* 区块标题 */
.section-title {
  font-size: var(--font-size-h2);
  font-weight: 700;
  margin-bottom: 12px;
}

.section-desc {
  font-size: 15px;
  color: var(--color-text-sub);
  margin-bottom: 16px;
}

/* 信息提示条 */
.help-note {
  background-color: #eff6ff;
  border-left: 4px solid var(--color-primary);
  padding: 16px 20px;
  border-radius: 0 var(--radius-card) var(--radius-card) 0;
}

.help-note h2 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 8px;
}

.help-note p {
  font-size: 14px;
  line-height: 1.7;
  color: var(--color-text);
}

.help-note a {
  font-weight: 600;
}

/* ------------------------------------------------------------
   4. Pages —— 首页
   ------------------------------------------------------------ */

/* 首屏品牌定位区 */
.hero-intro {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 32px;
  align-items: center;
  padding: 48px 0 40px;
  border-bottom: 1px solid var(--color-border-light);
}

.hero-copy h1 {
  font-size: 28px;
  font-weight: 700;
  color: var(--color-primary-dark);
  margin-bottom: 12px;
  line-height: 1.35;
}

.hero-slogan {
  font-size: 17px;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 12px;
}

.hero-desc {
  font-size: 15px;
  color: var(--color-text-sub);
  margin-bottom: 24px;
  max-width: 520px;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.hero-figure {
  border-radius: var(--radius-card);
  overflow: hidden;
  border: 1px solid var(--color-border-light);
  background-color: var(--color-card);
}

.hero-figure img {
  width: 100%;
  height: 280px;
  object-fit: cover;
}

/* 首屏焦点内容区 */
.focus-cards {
  padding: 40px 0;
  border-bottom: 1px solid var(--color-border-light);
}

.focus-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.focus-card {
  background-color: var(--color-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-card);
  overflow: hidden;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.focus-card:hover {
  border-color: var(--color-primary);
  box-shadow: 0 2px 8px rgba(29, 78, 216, 0.08);
}

.focus-card img {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

.focus-card h3 {
  font-size: 17px;
  font-weight: 600;
  padding: 16px 16px 4px;
}

.focus-card p {
  font-size: 14px;
  color: var(--color-text-sub);
  padding: 0 16px;
  margin-bottom: 12px;
  line-height: 1.6;
}

.focus-card a {
  display: inline-block;
  padding: 8px 16px 16px;
  font-size: 14px;
  font-weight: 600;
  min-height: 24px;
}

/* 频道快速分类区 */
.channel-quick-nav {
  padding: 40px 0;
  border-bottom: 1px solid var(--color-border-light);
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.tag-list li a {
  display: inline-block;
  padding: 8px 20px;
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-tag);
  font-size: 14px;
  color: var(--color-text);
  min-height: 44px;
  line-height: 26px;
  transition: background-color var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast);
}

.tag-list li a:hover {
  background-color: #eff6ff;
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* 专题与指南入口区 */
.entry-cards {
  padding: 40px 0;
  border-bottom: 1px solid var(--color-border-light);
}

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

.entry-card {
  background-color: var(--color-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-card);
  padding: 28px;
  transition: border-color var(--transition-fast);
}

.entry-card:hover {
  border-color: var(--color-primary);
}

.entry-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
}

.entry-card p {
  font-size: 14px;
  color: var(--color-text-sub);
  margin-bottom: 16px;
  line-height: 1.6;
}

.entry-card a {
  font-size: 14px;
  font-weight: 600;
  display: inline-block;
  min-height: 24px;
}

/* 帮助说明区 */
.help-note {
  margin: 40px 0;
}

/* ------------------------------------------------------------
   5. Pages —— 频道索引（klys/pindao.html）
   ------------------------------------------------------------ */

.channel-quick-bar {
  margin-bottom: 28px;
}

.quick-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 12px;
  background-color: var(--color-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-card);
}

.quick-links a {
  display: inline-block;
  padding: 8px 16px;
  font-size: 14px;
  color: var(--color-text);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-tag);
  min-height: 40px;
  line-height: 22px;
  background-color: var(--color-bg);
  transition: background-color var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast);
}

.quick-links a:hover {
  background-color: #eff6ff;
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* 频道卡片网格 */
.channel-card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 32px;
}

.channel-card {
  background-color: var(--color-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-card);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.channel-card:hover {
  border-color: var(--color-primary);
  box-shadow: 0 2px 8px rgba(29, 78, 216, 0.08);
}

.channel-card img {
  width: 100%;
  height: 160px;
  object-fit: cover;
}

.channel-card h2 {
  font-size: 17px;
  font-weight: 600;
  padding: 16px 16px 4px;
}

.channel-card p {
  font-size: 14px;
  color: var(--color-text-sub);
  padding: 0 16px;
  margin-bottom: 12px;
  line-height: 1.6;
  flex: 1;
}

.channel-card a {
  display: inline-block;
  padding: 8px 16px 16px;
  font-size: 14px;
  font-weight: 600;
  min-height: 24px;
}

/* 频道索引说明区 */
.channel-index-note {
  background-color: var(--color-card);
  border: 1px solid var(--color-border-light);
  border-left: 4px solid var(--color-primary);
  border-radius: 0 var(--radius-card) var(--radius-card) 0;
  padding: 20px 24px;
  margin-top: 8px;
}

.channel-index-note h2 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 8px;
}

.channel-index-note p {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
}

.channel-index-note a {
  font-weight: 600;
  margin-right: 16px;
  display: inline-block;
  min-height: 24px;
  padding: 4px 0;
}

/* ------------------------------------------------------------
   6. Pages —— 专题片单（klys/zhuanti.html）
   ------------------------------------------------------------ */

.layout-shell {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 32px;
  align-items: start;
}

.topic-main {
  min-width: 0;
}

.topic-section {
  background-color: var(--color-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-card);
  padding: 24px;
  margin-bottom: 24px;
}

.topic-section h2 {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-primary-dark);
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border-light);
}

.topic-figure {
  margin: 12px 0 16px;
  border-radius: var(--radius-card);
  overflow: hidden;
  border: 1px solid var(--color-border-light);
}

.topic-figure img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.topic-figure figcaption {
  font-size: var(--font-size-small);
  color: var(--color-text-sub);
  padding: 8px 12px;
  background-color: var(--color-bg);
  line-height: 1.5;
}

.topic-desc {
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: 12px;
}

.topic-desc:last-child {
  margin-bottom: 0;
}

.topic-desc a {
  font-weight: 600;
}

/* 侧栏 */
.topic-sidebar {
  background-color: var(--color-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-card);
  padding: 20px;
  position: sticky;
  top: calc(var(--header-height) + 16px);
}

.topic-sidebar h2 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border-light);
}

.sidebar-links li {
  margin-bottom: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-border-light);
}

.sidebar-links li:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}

.sidebar-links a {
  font-size: 15px;
  font-weight: 600;
  display: block;
  min-height: 24px;
  margin-bottom: 4px;
}

.sidebar-links p {
  font-size: 13px;
  color: var(--color-text-sub);
  line-height: 1.5;
}

/* ------------------------------------------------------------
   7. Pages —— 观看指南（klys/zhinan.html）
   ------------------------------------------------------------ */

.guide-section {
  max-width: 800px;
  margin: 0 auto 32px;
  background-color: var(--color-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-card);
  padding: 28px;
}

.guide-section h2 {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-primary-dark);
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border-light);
}

.guide-section > p {
  font-size: 14px;
  color: var(--color-text-sub);
  margin-bottom: 16px;
  line-height: 1.7;
}

/* 准备事项 */
.prep-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.prep-list li {
  background-color: var(--color-bg);
  border-radius: var(--radius-card);
  padding: 16px;
  border: 1px solid var(--color-border-light);
}

.prep-list h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--color-text);
}

.prep-list p {
  font-size: 14px;
  color: var(--color-text-sub);
  line-height: 1.6;
}

/* 指南配图 */
.guide-figure {
  margin: 16px 0;
  border-radius: var(--radius-card);
  overflow: hidden;
  border: 1px solid var(--color-border-light);
}

.guide-figure img {
  width: 100%;
  height: 220px;
  object-fit: cover;
}

.guide-figure figcaption {
  font-size: var(--font-size-small);
  color: var(--color-text-sub);
  padding: 8px 12px;
  background-color: var(--color-bg);
  line-height: 1.5;
}

/* 操作步骤 */
.step-list {
  counter-reset: step-counter;
}

.step-list li {
  position: relative;
  padding: 16px 16px 16px 56px;
  border-bottom: 1px solid var(--color-border-light);
  counter-increment: step-counter;
}

.step-list li:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.step-list li::before {
  content: counter(step-counter);
  position: absolute;
  left: 12px;
  top: 16px;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background-color: var(--color-primary);
  color: #ffffff;
  font-size: 15px;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

.step-list h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 4px;
}

.step-list p {
  font-size: 14px;
  color: var(--color-text-sub);
  line-height: 1.6;
}

.step-list a {
  font-weight: 600;
}

/* 时间与异常 */
.time-note,
.exception-note {
  background-color: var(--color-bg);
  border-radius: var(--radius-card);
  padding: 16px;
  margin-bottom: 16px;
  border: 1px solid var(--color-border-light);
}

.time-note:last-child,
.exception-note:last-child {
  margin-bottom: 0;
}

.time-note h3,
.exception-note h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 6px;
}

.time-note p,
.exception-note p {
  font-size: 14px;
  color: var(--color-text-sub);
  line-height: 1.6;
}

/* 结果核验 */
.verify-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.verify-list li {
  background-color: var(--color-bg);
  border-radius: var(--radius-card);
  padding: 16px;
  border: 1px solid var(--color-border-light);
}

.verify-list h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--color-text);
}

.verify-list p {
  font-size: 14px;
  color: var(--color-text-sub);
  line-height: 1.6;
}

/* ------------------------------------------------------------
   8. Pages —— 常见问题（klys/wenti.html）
   ------------------------------------------------------------ */

.qa-reference-image {
  margin-bottom: 24px;
  border-radius: var(--radius-card);
  overflow: hidden;
  border: 1px solid var(--color-border-light);
  max-width: 800px;
}

.qa-reference-image img {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

.qa-reference-image figcaption {
  font-size: var(--font-size-small);
  color: var(--color-text-sub);
  padding: 8px 12px;
  background-color: var(--color-card);
  line-height: 1.5;
  border-top: 1px solid var(--color-border-light);
}

/* 问题分类锚点 */
.qa-category-nav {
  margin-bottom: 28px;
  background-color: var(--color-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-card);
  padding: 12px;
}

.qa-category-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.qa-category-nav a {
  display: inline-block;
  padding: 8px 16px;
  font-size: 14px;
  color: var(--color-text);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-tag);
  min-height: 40px;
  line-height: 22px;
  background-color: var(--color-bg);
  transition: background-color var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast);
}

.qa-category-nav a:hover {
  background-color: #eff6ff;
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* FAQ 分组 */
.qa-group {
  margin-bottom: 32px;
}

.qa-group h2 {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-primary-dark);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border-light);
}

.qa-item {
  margin-bottom: 12px;
}

.qa-item details {
  background-color: var(--color-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-card);
  overflow: hidden;
}

.qa-item summary {
  padding: 16px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  line-height: 1.5;
  min-height: 44px;
  list-style: none;
  position: relative;
  padding-right: 40px;
}

.qa-item summary::-webkit-details-marker {
  display: none;
}

.qa-item summary::after {
  content: "+";
  position: absolute;
  right: 16px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 20px;
  color: var(--color-primary);
  font-weight: 400;
}

.qa-item details[open] summary::after {
  content: "−";
}

.qa-item details[open] summary {
  border-bottom: 1px solid var(--color-border-light);
}

.qa-item details p {
  padding: 16px;
  font-size: 14px;
  color: var(--color-text-sub);
  line-height: 1.7;
  background-color: var(--color-bg);
}

.qa-item details p a {
  font-weight: 600;
}

/* 后续入口 */
.qa-followup {
  background-color: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: var(--radius-card);
  padding: 20px 24px;
  margin-top: 32px;
}

.qa-followup h2 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 8px;
}

.qa-followup p {
  font-size: 14px;
  line-height: 1.7;
}

.qa-followup a {
  font-weight: 600;
  margin-right: 16px;
  display: inline-block;
  padding: 4px 0;
  min-height: 24px;
}

/* ------------------------------------------------------------
   9. Pages —— 帮助反馈（klys/bangzhu.html）
   ------------------------------------------------------------ */

.help-section {
  max-width: 860px;
  margin: 0 auto 32px;
  background-color: var(--color-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-card);
  padding: 28px;
}

.help-section h2 {
  font-size: 18px;
  font-weight: 600;
  color: var(--color-primary-dark);
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border-light);
}

.section-lead {
  font-size: 14px;
  color: var(--color-text-sub);
  margin-bottom: 16px;
  line-height: 1.7;
}

/* 自助排查步骤 */
.troubleshoot-steps {
  counter-reset: troubleshoot-counter;
}

.troubleshoot-steps li {
  position: relative;
  padding: 16px 16px 16px 56px;
  border-bottom: 1px solid var(--color-border-light);
  counter-increment: troubleshoot-counter;
}

.troubleshoot-steps li:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.troubleshoot-steps li::before {
  content: counter(troubleshoot-counter);
  position: absolute;
  left: 12px;
  top: 16px;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background-color: var(--color-accent);
  color: #ffffff;
  font-size: 15px;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

.troubleshoot-steps h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 4px;
}

.troubleshoot-steps p {
  font-size: 14px;
  color: var(--color-text-sub);
  line-height: 1.6;
}

.troubleshoot-steps a {
  font-weight: 600;
}

/* 排查流程图 */
.help-figure {
  max-width: 860px;
  margin: 0 auto 32px;
  border-radius: var(--radius-card);
  overflow: hidden;
  border: 1px solid var(--color-border-light);
  background-color: var(--color-card);
}

.help-figure img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.help-figure figcaption {
  font-size: var(--font-size-small);
  color: var(--color-text-sub);
  padding: 8px 12px;
  background-color: var(--color-bg);
  line-height: 1.5;
}

/* 反馈信息整理 */
.feedback-list {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.feedback-list li {
  background-color: var(--color-bg);
  border-radius: var(--radius-card);
  padding: 16px;
  border: 1px solid var(--color-border-light);
}

.feedback-list h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--color-text);
}

.feedback-list p {
  font-size: 14px;
  color: var(--color-text-sub);
  line-height: 1.6;
}

/* 帮助反馈页的提示条 */
.help-note {
  max-width: 860px;
  margin: 0 auto 32px;
}

/* ------------------------------------------------------------
   10. Pages —— 404
   ------------------------------------------------------------ */

.error-main {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 48px var(--container-padding);
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.error-panel {
  background-color: var(--color-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-card);
  padding: 48px 32px;
  text-align: center;
  margin-bottom: 32px;
}

.error-code {
  font-size: 48px;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1;
  margin-bottom: 16px;
}

.error-panel h1 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 12px;
}

.error-desc {
  font-size: 15px;
  color: var(--color-text-sub);
  margin-bottom: 24px;
  max-width: 480px;
  margin-left: auto;
  margin-right: auto;
}

.error-home-link {
  display: inline-block;
  min-height: 44px;
  padding: 10px 24px;
  background-color: var(--color-primary);
  color: #ffffff;
  border-radius: var(--radius-tag);
  font-size: 15px;
  font-weight: 600;
  line-height: 24px;
  border: 1px solid var(--color-primary);
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.error-home-link:hover {
  background-color: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  color: #ffffff;
}

.error-help {
  background-color: var(--color-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-card);
  padding: 24px;
}

.error-help h2 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border-light);
}

.error-help ul {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.error-help li a {
  display: block;
  padding: 12px 16px;
  background-color: var(--color-bg);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-card);
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text);
  min-height: 44px;
  line-height: 1.4;
  transition: background-color var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast);
}

.error-help li a:hover {
  background-color: #eff6ff;
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* ------------------------------------------------------------
   11. Responsive —— 响应式断点
   ------------------------------------------------------------ */

/* 手机端 768px 断点 */
@media (max-width: 768px) {
  /* 页头 */
  .header-inner {
    height: auto;
    min-height: var(--header-height);
    flex-wrap: wrap;
    padding-top: 10px;
    padding-bottom: 10px;
  }

  .site-brand {
    line-height: 44px;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    width: 100%;
    order: 3;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    width: 100%;
    border-top: 1px solid var(--color-border-light);
    padding-top: 4px;
  }

  .nav-list.is-open {
    display: flex;
  }

  .nav-list a {
    display: block;
    padding: 12px 8px;
    border-bottom: 1px solid var(--color-border-light);
    min-height: 44px;
    line-height: 20px;
  }

  /* 页脚 */
  .footer-inner {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    padding-top: 32px;
  }

  /* 首页 */
  .hero-intro {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 32px 0 28px;
  }

  .hero-copy h1 {
    font-size: 24px;
  }

  .hero-figure img {
    height: 200px;
  }

  .focus-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .entry-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .entry-card {
    padding: 20px;
  }

  /* 频道索引 */
  .channel-card-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  .quick-links {
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    padding-bottom: 8px;
  }

  .quick-links a {
    flex-shrink: 0;
    white-space: nowrap;
  }

  /* 专题片单 */
  .layout-shell {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .topic-sidebar {
    position: static;
  }

  /* 观看指南 */
  .guide-section {
    padding: 20px;
  }

  .prep-list {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .verify-list {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  /* 常见问题 */
  .qa-category-nav ul {
    flex-wrap: nowrap;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    padding-bottom: 4px;
  }

  .qa-category-nav a {
    flex-shrink: 0;
    white-space: nowrap;
  }

  /* 帮助反馈 */
  .help-section {
    padding: 20px;
  }

  .feedback-list {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  /* 404 */
  .error-help ul {
    grid-template-columns: repeat(2, 1fr);
  }

  .error-panel {
    padding: 32px 20px;
  }
}

/* 平板 769px - 1024px */
@media (min-width: 769px) and (max-width: 1024px) {
  .channel-card-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .focus-card:last-child {
    grid-column: 1 / -1;
    max-width: calc(50% - 12px);
  }

  .layout-shell {
    grid-template-columns: 1fr 280px;
    gap: 24px;
  }
}

/* 大屏 1025px 以上保持默认 */

/* ------------------------------------------------------------
   12. 动效与可访问性
   ------------------------------------------------------------ */

/* 尊重系统减少动效偏好 */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
  }
}

/* 键盘焦点可见 */
a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* 程序验收反馈：修复网格孤项 */
@media (min-width: 769px) {
  .channel-card-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}