/* =========================================================
   秋霞影院 · 全站样式表
   base → layout → components → pages → responsive
   ========================================================= */

/* ---------------------------------------------------------
   1. base：变量、重置、排版、通用工具类
   --------------------------------------------------------- */
:root {
  --bg: #f7f8fa;
  --surface: #ffffff;
  --text: #1f2430;
  --text-muted: #5b6472;
  --line: #e3e6ec;
  --line-strong: #d3d8e2;
  --accent: #2f6fed;
  --accent-soft: #eaf1fe;
  --accent-deep: #1f56c9;
  --radius: 8px;
  --radius-sm: 6px;
  --shadow-sm: 0 1px 2px rgba(31, 36, 48, 0.05);
  --shadow-md: 0 4px 14px rgba(31, 36, 48, 0.07);
  --container: 1120px;
  --gutter: 24px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

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

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  color: var(--text);
  font-weight: 600;
  line-height: 1.35;
}

p {
  margin: 0;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

dl,
dd,
dt {
  margin: 0;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.18s ease;
}

a:hover,
a:focus-visible {
  color: var(--accent-deep);
}

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

figure {
  margin: 0;
}

button {
  font: inherit;
  color: inherit;
}

table {
  border-collapse: collapse;
  width: 100%;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -48px;
  left: 16px;
  z-index: 60;
  padding: 10px 16px;
  background: var(--surface);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-md);
  transition: top 0.2s ease;
}

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

/* ---------------------------------------------------------
   2. layout：全站骨架（页头、导航、主容器、内页、页脚）
   --------------------------------------------------------- */
.site-body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--text);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: var(--surface);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--gutter);
  min-height: 64px;
  display: flex;
  align-items: center;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 0;
  color: var(--text);
  font-size: 18px;
  font-weight: 600;
  white-space: nowrap;
}

.brand:hover,
.brand:focus-visible {
  color: var(--accent-deep);
}

.brand-mark {
  width: 26px;
  height: 26px;
  flex: none;
  border-radius: 7px;
  background: var(--accent);
  box-shadow: inset 0 0 0 6px var(--accent-soft);
}

.brand-name {
  line-height: 1;
}

.site-nav {
  margin-left: auto;
}

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

.nav-list a {
  display: block;
  padding: 10px 12px;
  color: var(--text-muted);
  font-size: 15px;
  border-bottom: 2px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.nav-list a:hover,
.nav-list a:focus-visible {
  color: var(--accent-deep);
  background: var(--accent-soft);
}

.nav-list a.is-current {
  color: var(--text);
  font-weight: 600;
  border-bottom-color: var(--accent);
}

.nav-toggle {
  display: none;
  margin-left: auto;
  width: 44px;
  height: 44px;
  padding: 0;
  align-items: center;
  justify-content: center;
  background: var(--surface);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  cursor: pointer;
}

.nav-toggle-bar,
.nav-toggle-bar::before,
.nav-toggle-bar::after {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--text);
  transition: transform 0.2s ease, background 0.2s ease;
}

.nav-toggle-bar {
  position: relative;
}

.nav-toggle-bar::before,
.nav-toggle-bar::after {
  content: "";
  position: absolute;
  left: 0;
}

.nav-toggle-bar::before {
  top: -6px;
}

.nav-toggle-bar::after {
  top: 6px;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar {
  background: transparent;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar::before {
  transform: translateY(6px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar::after {
  transform: translateY(-6px) rotate(-45deg);
}

.site-main {
  flex: 1 0 auto;
  width: 100%;
}

.inner-main {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 24px var(--gutter) 64px;
}

.home-main {
  padding-bottom: 64px;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: 20px;
  font-size: 14px;
  color: var(--text-muted);
}

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

.breadcrumb a:hover,
.breadcrumb a:focus-visible {
  color: var(--accent-deep);
}

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

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

.page-header {
  padding-bottom: 20px;
  margin-bottom: 28px;
  border-bottom: 1px solid var(--line);
}

.page-title {
  font-size: 28px;
  font-weight: 600;
}

.page-description {
  margin-top: 10px;
  max-width: 760px;
  color: var(--text-muted);
  font-size: 15px;
}

.site-footer {
  flex: none;
  background: var(--surface);
  border-top: 1px solid var(--line);
  color: var(--text-muted);
  font-size: 14px;
}

.footer-inner {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 40px var(--gutter) 28px;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 32px;
}

.footer-col {
  min-width: 0;
}

.footer-brand {
  color: var(--text);
  font-size: 16px;
  font-weight: 600;
}

.footer-desc {
  margin-top: 8px;
  line-height: 1.7;
}

.footer-heading {
  margin-bottom: 12px;
  color: var(--text);
  font-size: 14px;
  font-weight: 600;
}

.footer-list li + li {
  margin-top: 8px;
}

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

.footer-list a:hover,
.footer-list a:focus-visible {
  color: var(--accent-deep);
}

.footer-bottom {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 16px var(--gutter) 24px;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.footer-copy {
  color: var(--text-muted);
  font-size: 13px;
}

.back-top {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text-muted);
  font-size: 13px;
}

.back-top:hover,
.back-top:focus-visible {
  border-color: var(--accent);
  color: var(--accent-deep);
  background: var(--accent-soft);
}

/* ---------------------------------------------------------
   3. components：通用按钮、区块头、表格、步骤、卡片
   --------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 500;
  transition: background 0.18s ease, border-color 0.18s ease, color 0.18s ease;
}

.btn-primary {
  background: var(--accent);
  color: #ffffff;
}

.btn-primary:hover,
.btn-primary:focus-visible {
  background: var(--accent-deep);
  color: #ffffff;
}

.btn-ghost {
  background: var(--surface);
  border-color: var(--line-strong);
  color: var(--text);
}

.btn-ghost:hover,
.btn-ghost:focus-visible {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent-deep);
}

.section-head {
  margin-bottom: 20px;
}

.section-title {
  font-size: 20px;
  font-weight: 600;
}

.section-desc,
.section-lead {
  margin-top: 8px;
  max-width: 780px;
  color: var(--text-muted);
  font-size: 15px;
}

.section-lead {
  margin-bottom: 20px;
}

.section-foot {
  margin-top: 20px;
  font-size: 15px;
}

.text-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  min-height: 32px;
  color: var(--accent);
  font-weight: 500;
}

.text-link::after {
  content: "→";
  font-size: 13px;
  transition: transform 0.18s ease;
}

.text-link:hover::after,
.text-link:focus-visible::after {
  transform: translateX(3px);
}

.table-wrap {
  overflow-x: auto;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.data-table,
.field-table {
  min-width: 640px;
  font-size: 15px;
}

.data-table th,
.data-table td,
.field-table th,
.field-table td {
  padding: 12px 16px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line);
}

.data-table thead th,
.field-table thead th {
  background: var(--bg);
  color: var(--text-muted);
  font-size: 13px;
  font-weight: 600;
  white-space: nowrap;
}

.data-table tbody th,
.field-table tbody th {
  color: var(--text);
  font-size: 15px;
  font-weight: 600;
  white-space: nowrap;
}

.data-table tbody tr:last-child th,
.data-table tbody tr:last-child td,
.field-table tbody tr:last-child th,
.field-table tbody tr:last-child td {
  border-bottom: 0;
}

.data-table tbody tr:hover,
.field-table tbody tr:hover {
  background: var(--accent-soft);
}

.step-list {
  counter-reset: step;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}

.step-item {
  position: relative;
  padding: 18px 18px 18px 56px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.step-item::before {
  counter-increment: step;
  content: counter(step, decimal-leading-zero);
  position: absolute;
  top: 18px;
  left: 18px;
  width: 24px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--accent);
}

.step-title {
  font-size: 17px;
  font-weight: 600;
}

.step-desc,
.step-text {
  margin-top: 8px;
  color: var(--text-muted);
  font-size: 15px;
}

.step-desc a,
.step-text a {
  color: var(--accent);
}

/* ---------------------------------------------------------
   4. pages：各页面业务模块
   --------------------------------------------------------- */

/* 4.1 首页 hero */
.hero {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
}

.hero-inner {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 48px var(--gutter);
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 40px;
  align-items: center;
}

.hero-copy {
  min-width: 0;
}

.hero-eyebrow {
  margin-bottom: 12px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.hero-title {
  font-size: 32px;
  font-weight: 600;
}

.hero-desc {
  margin-top: 14px;
  max-width: 520px;
  color: var(--text-muted);
  font-size: 16px;
}

.hero-actions {
  margin-top: 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.hero-media {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--bg);
}

.hero-media img {
  width: 100%;
  height: 300px;
  object-fit: cover;
}

/* 4.2 首页 · 题材频道方向总览 */
.channel-overview {
  max-width: var(--container);
  margin: 0 auto;
  padding: 56px var(--gutter) 0;
}

.channel-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 12px;
}

.channel-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 18px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

.channel-item:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
}

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

.channel-name {
  font-size: 17px;
  font-weight: 600;
}

.channel-scope {
  margin-top: 6px;
  color: var(--text-muted);
  font-size: 14px;
}

.channel-link {
  flex: none;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  border-radius: var(--radius-sm);
  background: var(--accent-soft);
  color: var(--accent-deep);
  font-size: 14px;
  font-weight: 500;
}

.channel-link:hover,
.channel-link:focus-visible {
  background: var(--accent);
  color: #ffffff;
}

.section-media {
  margin-top: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--surface);
}

.section-media img {
  width: 100%;
  height: 260px;
  object-fit: cover;
}

.section-media-caption {
  padding: 12px 18px;
  border-top: 1px solid var(--line);
  color: var(--text-muted);
  font-size: 14px;
}

/* 4.3 首页 · 专题片单速览 */
.topic-list {
  max-width: var(--container);
  margin: 0 auto;
  padding: 56px var(--gutter) 0;
}

.topic-items {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.topic-item {
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

.topic-item:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
}

.topic-name {
  font-size: 17px;
  font-weight: 600;
}

.topic-meta {
  margin-top: 14px;
  display: grid;
  grid-template-columns: 88px minmax(0, 1fr);
  gap: 8px 12px;
  font-size: 14px;
}

.topic-meta dt {
  color: var(--text-muted);
}

.topic-meta dd {
  color: var(--text);
}

/* 4.4 首页 · 字段表与浏览路径 */
.field-table-section,
.field-table + .section-foot {
  max-width: var(--container);
}

.path-steps {
  max-width: var(--container);
  margin: 0 auto;
  padding: 56px var(--gutter) 0;
}

/* 4.5 首页 · 收录边界与反馈入口 */
.boundary {
  max-width: var(--container);
  margin: 56px auto 0;
  padding: 32px var(--gutter);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.boundary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

.boundary-block {
  padding: 18px;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.boundary-heading {
  font-size: 16px;
  font-weight: 600;
}

.boundary-list {
  margin-top: 12px;
  display: grid;
  gap: 8px;
}

.boundary-list li {
  position: relative;
  padding-left: 18px;
  color: var(--text-muted);
  font-size: 15px;
}

.boundary-list li::before {
  content: "";
  position: absolute;
  top: 11px;
  left: 2px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}

.boundary-note {
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  color: var(--text-muted);
  font-size: 14px;
}

/* 4.6 内页 · 题材频道（pindao） */
.channel-groups {
  margin-bottom: 48px;
}

.channel-group-list {
  display: grid;
  gap: 20px;
}

.channel-group {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  gap: 24px;
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

.channel-group:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
}

.channel-group-media {
  margin: 0;
  border-radius: var(--radius-sm);
  overflow: hidden;
  background: var(--bg);
}

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

.channel-group-body {
  min-width: 0;
}

.channel-group-title {
  font-size: 18px;
  font-weight: 600;
}

.channel-group-desc {
  margin-top: 8px;
  color: var(--text-muted);
  font-size: 15px;
}

.channel-group-meta {
  margin-top: 14px;
  display: grid;
  grid-template-columns: 96px minmax(0, 1fr);
  gap: 8px 12px;
  font-size: 14px;
}

.channel-group-meta dt {
  color: var(--text-muted);
}

.channel-group-meta dd {
  color: var(--text);
}

.channel-group-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  margin-top: 16px;
  padding: 0 16px;
  border-radius: var(--radius-sm);
  background: var(--accent-soft);
  color: var(--accent-deep);
  font-size: 14px;
  font-weight: 500;
}

.channel-group-link:hover,
.channel-group-link:focus-visible {
  background: var(--accent);
  color: #ffffff;
}

.browse-order {
  margin-bottom: 8px;
}

.browse-order .step-list {
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.browse-order-note {
  margin-top: 20px;
  padding: 16px 18px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  color: var(--text-muted);
  font-size: 15px;
}

/* 4.7 内页 · 专题片单（zhuanti） */
.container {
  width: 100%;
}

.page-zhuanti .section {
  margin-bottom: 48px;
}

.page-zhuanti .topic-list .topic-item {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 24px;
  padding: 20px;
}

.topic-figure {
  margin: 0;
  border-radius: var(--radius-sm);
  overflow: hidden;
  background: var(--bg);
}

.topic-figure img {
  width: 100%;
  height: 150px;
  object-fit: cover;
}

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

.topic-scope,
.topic-makeup,
.topic-advice {
  margin-top: 10px;
  color: var(--text-muted);
  font-size: 15px;
}

.topic-scope {
  margin-top: 12px;
}

.field-label {
  display: inline-block;
  min-width: 68px;
  margin-right: 8px;
  color: var(--text);
  font-weight: 600;
}

.diff-columns {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.diff-col {
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.diff-col-channel {
  border-top: 3px solid var(--accent);
}

.diff-col-topic {
  border-top: 3px solid var(--line-strong);
}

.diff-heading {
  font-size: 17px;
  font-weight: 600;
}

.diff-text {
  margin-top: 10px;
  color: var(--text-muted);
  font-size: 15px;
}

.topic-tips .tips-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 12px;
}

.tips-item {
  position: relative;
  padding: 16px 18px 16px 44px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--text-muted);
  font-size: 15px;
}

.tips-item::before {
  content: "";
  position: absolute;
  top: 22px;
  left: 18px;
  width: 10px;
  height: 10px;
  border-radius: 2px;
  background: var(--accent-soft);
  box-shadow: inset 0 0 0 2px var(--accent);
}

/* 4.8 内页 · 条目字段说明（ziduan） */
.field-preview {
  margin-bottom: 48px;
}

.media-figure {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--surface);
}

.media-figure img {
  width: 100%;
  height: 320px;
  object-fit: cover;
}

.media-figure figcaption {
  padding: 12px 18px;
  border-top: 1px solid var(--line);
  color: var(--text-muted);
  font-size: 14px;
}

.field-table-section {
  margin-bottom: 48px;
}

.read-order {
  margin-bottom: 8px;
}

.read-order .step-list {
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.read-order .section-foot {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

/* 4.9 内页 · 收录边界与反馈（shoulu） */
.page-container {
  width: 100%;
}

.page-shoulu .section {
  margin-bottom: 48px;
}

.scope-body {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.scope-col {
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.scope-in {
  border-top: 3px solid var(--accent);
}

.scope-out {
  border-top: 3px solid var(--line-strong);
}

.scope-subtitle {
  font-size: 17px;
  font-weight: 600;
}

.scope-list {
  margin-top: 12px;
  display: grid;
  gap: 8px;
}

.scope-list li {
  position: relative;
  padding-left: 18px;
  color: var(--text-muted);
  font-size: 15px;
}

.scope-list li::before {
  content: "";
  position: absolute;
  top: 10px;
  left: 2px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}

.scope-figure {
  margin: 20px 0 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--surface);
}

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

.scope-figure figcaption {
  padding: 12px 18px;
  border-top: 1px solid var(--line);
  color: var(--text-muted);
  font-size: 14px;
}

.standard-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}

.standard-item {
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

.standard-item:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
}

.standard-name {
  font-size: 17px;
  font-weight: 600;
}

.standard-text {
  margin-top: 10px;
  color: var(--text-muted);
  font-size: 15px;
}

.standard-item .text-link {
  margin-top: 12px;
}

.feedback-steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}

.feedback-step {
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.feedback-step .step-index {
  display: inline-block;
  margin-bottom: 10px;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  background: var(--accent-soft);
  color: var(--accent-deep);
  font-family: var(--font-mono);
  font-size: 13px;
}

.feedback-step .text-link {
  margin-top: 12px;
}

.feedback-note {
  margin-top: 24px;
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.note-title {
  font-size: 17px;
  font-weight: 600;
}

.note-list {
  margin-top: 12px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 8px 20px;
}

.note-list li {
  position: relative;
  padding-left: 18px;
  color: var(--text-muted);
  font-size: 15px;
}

.note-list li::before {
  content: "";
  position: absolute;
  top: 10px;
  left: 2px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--line-strong);
}

.faq-list {
  display: grid;
  gap: 12px;
}

.faq-item {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.faq-question {
  position: relative;
  padding: 16px 48px 16px 18px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

.faq-question::-webkit-details-marker {
  display: none;
}

.faq-question::after {
  content: "+";
  position: absolute;
  top: 50%;
  right: 18px;
  transform: translateY(-50%);
  color: var(--accent);
  font-size: 20px;
  line-height: 1;
}

.faq-item[open] .faq-question::after {
  content: "–";
}

.faq-question:hover {
  background: var(--accent-soft);
}

.faq-answer {
  padding: 0 18px 18px;
  border-top: 1px solid var(--line);
  color: var(--text-muted);
  font-size: 15px;
}

.faq-answer p {
  margin-top: 12px;
}

.next-links {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 12px;
}

.next-link-item a {
  display: flex;
  align-items: center;
  min-height: 52px;
  padding: 0 18px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--text);
  font-weight: 500;
  transition: border-color 0.18s ease, background 0.18s ease, color 0.18s ease;
}

.next-link-item a:hover,
.next-link-item a:focus-visible {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent-deep);
}

/* 4.10 404 */
.error-main {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 64px var(--gutter);
}

.error-inner {
  width: 100%;
  max-width: 640px;
  padding: 32px;
  text-align: left;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.error-code {
  font-family: var(--font-mono);
  font-size: 40px;
  font-weight: 600;
  color: var(--accent);
  line-height: 1;
}

.error-inner h1 {
  margin-top: 12px;
  font-size: 26px;
}

.error-text {
  margin-top: 12px;
  color: var(--text-muted);
  font-size: 15px;
}

.error-actions {
  margin-top: 24px;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn-home {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  border-radius: var(--radius-sm);
  background: var(--accent);
  color: #ffffff;
  font-size: 15px;
  font-weight: 500;
}

.btn-home:hover,
.btn-home:focus-visible {
  background: var(--accent-deep);
  color: #ffffff;
}

.btn-plain {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 16px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text);
  font-size: 15px;
}

.btn-plain:hover,
.btn-plain:focus-visible {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent-deep);
}

.error-note {
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  color: var(--text-muted);
  font-size: 14px;
}

/* ---------------------------------------------------------
   5. responsive：平板与手机
   --------------------------------------------------------- */
@media (max-width: 960px) {
  .hero-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 28px;
    padding: 40px var(--gutter);
  }

  .hero-media img {
    height: 260px;
  }

  .channel-group,
  .page-zhuanti .topic-list .topic-item {
    grid-template-columns: minmax(0, 1fr);
  }

  .channel-group-media img,
  .topic-figure img {
    height: 180px;
  }

  .footer-inner {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 28px;
  }
}

@media (max-width: 768px) {
  .header-inner {
    flex-wrap: wrap;
    padding-top: 8px;
    padding-bottom: 8px;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .site-nav {
    order: 3;
    width: 100%;
    margin-left: 0;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 8px 0 12px;
    border-top: 1px solid var(--line);
  }

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

  .nav-list a {
    min-height: 44px;
    display: flex;
    align-items: center;
    padding: 0 8px;
    border-bottom: 1px solid var(--line);
  }

  .nav-list a.is-current {
    border-bottom-color: var(--accent);
    border-bottom-width: 2px;
  }

  .inner-main {
    padding: 20px var(--gutter) 48px;
  }

  .page-title {
    font-size: 24px;
  }

  .hero-title {
    font-size: 26px;
  }

  .channel-overview,
  .topic-list,
  .path-steps {
    padding-top: 40px;
  }

  .boundary {
    margin-top: 40px;
  }

  .media-figure img {
    height: 220px;
  }

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

  .section-media img {
    height: 200px;
  }

  .error-main {
    padding: 40px var(--gutter);
  }

  .error-inner {
    padding: 24px;
  }
}

@media (max-width: 560px) {
  :root {
    --gutter: 16px;
  }

  .footer-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 24px;
    padding-top: 32px;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }

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

  .topic-meta,
  .channel-group-meta {
    grid-template-columns: minmax(0, 1fr);
    gap: 2px 0;
  }

  .topic-meta dd,
  .channel-group-meta dd {
    margin-bottom: 8px;
  }

  .step-list,
  .browse-order .step-list,
  .read-order .step-list,
  .feedback-steps,
  .topic-tips .tips-list,
  .standard-grid,
  .next-links,
  .note-list {
    grid-template-columns: minmax(0, 1fr);
  }

  .error-code {
    font-size: 32px;
  }

  .error-inner h1 {
    font-size: 22px;
  }
}

@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;
  }
}