/* ==========================================================================
   樱花视频下载 · 全站样式表
   结构：base / layout / components / pages / responsive
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. base —— 变量、重置、排版基线
   -------------------------------------------------------------------------- */

:root {
  --c-text: #1f2328;
  --c-text-soft: #5a6169;
  --c-bg: #ffffff;
  --c-bg-soft: #f5f6f7;
  --c-line: #e2e5e8;
  --c-accent: #1f6f5c;
  --c-accent-soft: #e8f1ee;
  --c-warn: #a8562a;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Courier New", monospace;

  --w-wide: 1120px;
  --w-text: 720px;
  --w-side: 320px;
  --gap-col: 40px;

  --radius: 6px;
  --radius-sm: 4px;

  --shadow-hover: 0 2px 6px rgba(31, 35, 40, 0.06);
}

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

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

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-text);
  background-color: var(--c-bg);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  font-weight: 600;
  line-height: 1.3;
  color: var(--c-text);
}

p {
  margin: 0;
}

ul,
ol,
dl,
dd {
  margin: 0;
  padding: 0;
}

li {
  list-style: none;
}

a {
  color: var(--c-accent);
  text-decoration: none;
  transition: color 160ms ease;
}

a:hover,
a:focus-visible {
  color: var(--c-warn);
}

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--c-accent);
  outline-offset: 2px;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
  border-style: none;
}

button {
  font: inherit;
  color: inherit;
  cursor: pointer;
}

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

strong,
b {
  font-weight: 600;
}

/* --------------------------------------------------------------------------
   2. layout —— 页头、主导航、主容器、面包屑、页标题区、页脚
   -------------------------------------------------------------------------- */

/* 2.1 顶部事实条（仅首页） */
.fact-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  justify-content: space-between;
  align-items: center;
  max-width: var(--w-wide);
  margin: 0 auto;
  padding: 10px 24px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-text-soft);
  border-bottom: 1px solid var(--c-line);
}

.fact-bar-text,
.fact-bar-status {
  margin: 0;
}

.fact-bar-status {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-accent);
}

/* 2.2 页头 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  background-color: var(--c-bg);
  border-bottom: 1px solid var(--c-line);
}

.header-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 24px;
  max-width: var(--w-wide);
  margin: 0 auto;
  padding: 14px 24px;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 8px;
  color: var(--c-text);
  font-weight: 600;
  flex-shrink: 0;
}

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

.brand-mark {
  font-size: 19px;
  letter-spacing: 0.01em;
}

.brand-sub {
  font-size: 12px;
  font-weight: 400;
  color: var(--c-text-soft);
  letter-spacing: 0.02em;
}

/* 2.3 主导航 */
.site-nav {
  margin-left: auto;
}

.nav-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px 8px;
}

.nav-link {
  display: inline-block;
  padding: 8px 12px;
  font-size: 15px;
  color: var(--c-text);
  border-bottom: 2px solid transparent;
  border-radius: var(--radius-sm);
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--c-accent);
  background-color: var(--c-accent-soft);
}

.nav-link.is-current {
  color: var(--c-accent);
  border-bottom-color: var(--c-accent);
  font-weight: 600;
}

/* 2.4 汉堡按钮 */
.nav-toggle {
  display: none;
  margin-left: auto;
  width: 44px;
  height: 44px;
  padding: 11px 10px;
  background-color: var(--c-bg);
  border: 1px solid var(--c-line);
  border-radius: var(--radius-sm);
  flex-direction: column;
  justify-content: space-between;
}

.nav-toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--c-text);
  border-radius: 1px;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
  transform: translateY(9px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) {
  transform: translateY(-9px) rotate(-45deg);
}

/* 2.5 主容器 */
.site-main {
  display: block;
  max-width: var(--w-wide);
  margin: 0 auto;
  padding: 0 24px 72px;
}

.inner-main {
  padding-top: 20px;
}

/* 2.6 面包屑 */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  padding: 4px 0 16px;
  font-size: 13px;
  color: var(--c-text-soft);
}

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

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

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

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

/* 2.7 页标题区 */
.page-header {
  padding-bottom: 24px;
  margin-bottom: 32px;
  border-bottom: 1px solid var(--c-line);
}

.page-title {
  font-size: 30px;
  font-weight: 600;
  line-height: 1.3;
  color: var(--c-text);
}

.page-description {
  max-width: var(--w-text);
  margin-top: 12px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-text-soft);
}

/* 2.8 内页两栏布局：主内容在前，右侧栏在后 */
.page-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) var(--w-side);
  gap: var(--gap-col);
  align-items: start;
}

/* 2.9 页脚 */
.site-footer {
  margin-top: auto;
  background-color: var(--c-bg-soft);
  border-top: 1px solid var(--c-line);
}

.footer-inner {
  max-width: var(--w-wide);
  margin: 0 auto;
  padding: 40px 24px 24px;
}

.footer-cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--c-line);
}

.footer-cta-text {
  font-size: 15px;
  color: var(--c-text);
}

.footer-cta-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 18px;
  font-size: 15px;
  font-weight: 600;
  color: #ffffff;
  background-color: var(--c-accent);
  border-radius: var(--radius);
  transition: background-color 160ms ease;
}

.footer-cta-link:hover,
.footer-cta-link:focus-visible {
  color: #ffffff;
  background-color: #185a4a;
}

.footer-groups {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px 40px;
  padding: 28px 0;
}

.footer-group-title {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--c-text-soft);
}

.footer-list {
  margin-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-list a {
  display: inline-block;
  padding: 4px 0;
  font-size: 14px;
  color: var(--c-text);
}

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

.footer-bottom {
  padding-top: 20px;
  border-top: 1px solid var(--c-line);
}

.footer-note {
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

.footer-copy {
  margin-top: 8px;
  font-size: 12px;
  color: var(--c-text-soft);
}

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

/* 3.1 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 22px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius);
  border: 1px solid transparent;
  transition: background-color 160ms ease, border-color 160ms ease, color 160ms ease;
}

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

.btn-primary:hover,
.btn-primary:focus-visible {
  color: #ffffff;
  background-color: #185a4a;
}

.btn-ghost {
  color: var(--c-accent);
  background-color: var(--c-bg);
  border-color: var(--c-accent);
}

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

/* 3.2 通用 section 骨架 */
.section {
  padding: 40px 0;
  border-top: 1px solid var(--c-line);
}

.section:first-child {
  border-top: 0;
}

.section-head {
  margin-bottom: 24px;
}

.section-title {
  font-size: 20px;
  font-weight: 600;
  line-height: 1.3;
}

.section-desc,
.section-lead,
.section-intro,
.section-text {
  max-width: var(--w-text);
  margin-top: 10px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-text-soft);
}

.section-foot {
  margin-top: 20px;
  font-size: 14px;
}

.section-footnote {
  margin-top: 18px;
  font-size: 14px;
  color: var(--c-text-soft);
}

.section-footnote a {
  margin-right: 14px;
}

.section-figure {
  margin: 28px 0 0;
}

.section-figure img,
.guide-figure img {
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  background-color: var(--c-bg-soft);
}

.figure-caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

/* 3.3 站内推荐链接组 */
.next-links {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
}

.next-link-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 16px;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  background-color: var(--c-bg);
  transition: border-color 160ms ease, transform 160ms ease, box-shadow 160ms ease;
}

.next-link-item:hover {
  border-color: var(--c-accent);
  transform: translateY(-1px);
  box-shadow: var(--shadow-hover);
}

.next-link-item a {
  font-size: 15px;
  font-weight: 600;
  color: var(--c-accent);
}

.next-link-note {
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

/* 3.4 侧栏 */
.sidebar {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.sidebar-block {
  padding: 20px;
  background-color: var(--c-bg-soft);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

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

.sidebar-desc {
  margin-top: 8px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

/* --------------------------------------------------------------------------
   4. pages —— 各页专属模块
   -------------------------------------------------------------------------- */

/* 4.1 首页：首屏 */
.hero {
  padding: 40px 0 8px;
}

.hero-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: var(--gap-col);
  align-items: center;
}

.hero-eyebrow {
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--c-accent);
}

.hero-title {
  margin-top: 12px;
  font-size: 30px;
  font-weight: 600;
  line-height: 1.3;
}

.hero-lead {
  max-width: 560px;
  margin-top: 14px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-text-soft);
}

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

.hero-media {
  margin: 0;
}

.hero-media img {
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  background-color: var(--c-bg-soft);
}

.hero-media figcaption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

/* 4.2 首页：首屏速览表 */
.hero-table {
  margin-top: 36px;
  padding: 20px;
  background-color: var(--c-bg-soft);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

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

.quick-table {
  margin-top: 14px;
  font-size: 14px;
}

.quick-table th,
.quick-table td {
  padding: 10px 12px;
  text-align: left;
  border-bottom: 1px solid var(--c-line);
  vertical-align: top;
}

.quick-table th {
  font-weight: 600;
  color: var(--c-text-soft);
  white-space: nowrap;
}

.quick-table tbody tr:last-child td {
  border-bottom: 0;
}

.quick-table tbody tr:hover {
  background-color: var(--c-bg);
}

.hero-table-note {
  margin-top: 12px;
  font-size: 13px;
  color: var(--c-text-soft);
}

/* 4.3 首页：频道方向总表 */
.channel-rows {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--c-line);
}

.channel-row {
  display: grid;
  grid-template-columns: 64px minmax(0, 1fr);
  gap: 8px 20px;
  padding: 18px 0;
  border-bottom: 1px solid var(--c-line);
}

.channel-no {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--c-accent);
}

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

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

.channel-focus,
.channel-audience {
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

.channel-focus::before {
  content: "内容侧重：";
  font-weight: 600;
  color: var(--c-text);
}

.channel-audience::before {
  content: "适合人群：";
  font-weight: 600;
  color: var(--c-text);
}

/* 4.4 首页：专题片单入口 */
.playlist-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.playlist-card {
  display: flex;
  flex-direction: column;
  padding: 16px;
  background-color: var(--c-bg);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  transition: border-color 160ms ease, transform 160ms ease, box-shadow 160ms ease;
}

.playlist-card:hover {
  border-color: var(--c-accent);
  transform: translateY(-1px);
  box-shadow: var(--shadow-hover);
}

.playlist-media {
  margin: 0 0 14px;
}

.playlist-media img {
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: var(--radius-sm);
  background-color: var(--c-bg-soft);
}

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

.playlist-desc {
  margin-top: 8px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

.playlist-meta {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-text-soft);
}

.playlist-link {
  margin-top: 14px;
  font-size: 14px;
  font-weight: 600;
}

/* 4.5 首页：四步浏览顺序 */
.step-list {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.step-item {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 18px;
  background-color: var(--c-bg);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  transition: border-color 160ms ease, transform 160ms ease, box-shadow 160ms ease;
}

.step-item:hover {
  border-color: var(--c-accent);
  transform: translateY(-1px);
  box-shadow: var(--shadow-hover);
}

.step-toggle {
  display: flex;
  align-items: baseline;
  gap: 10px;
  width: 100%;
  padding: 0;
  background: none;
  border: 0;
  text-align: left;
}

.step-no {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-accent);
}

.step-name {
  font-size: 16px;
  font-weight: 600;
  color: var(--c-text);
}

.step-toggle:hover .step-name,
.step-toggle:focus-visible .step-name {
  color: var(--c-accent);
}

.step-need {
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

.step-panel {
  padding-top: 10px;
  border-top: 1px dashed var(--c-line);
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

.step-panel[hidden] {
  display: none;
}

/* 4.6 首页：站内栏目索引 */
.index-grid {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 16px;
}

.index-cell {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px;
  background-color: var(--c-bg-soft);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  transition: border-color 160ms ease, transform 160ms ease;
}

.index-cell:hover {
  border-color: var(--c-accent);
  transform: translateY(-1px);
}

.index-name {
  font-size: 16px;
  font-weight: 600;
}

.index-desc {
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

.index-link {
  margin-top: 8px;
  font-size: 13px;
  font-weight: 600;
}

/* 4.7 频道分类页：频道分类总览 */
.channel-table {
  border-top: 1px solid var(--c-line);
}

.channel-table .channel-row {
  display: grid;
  grid-template-columns: 64px minmax(0, 1fr) minmax(0, 1.2fr) minmax(0, 1fr);
  gap: 6px 20px;
  padding: 16px 0;
  border-bottom: 1px solid var(--c-line);
}

.channel-table .channel-row-head {
  font-size: 13px;
  font-weight: 600;
  color: var(--c-text-soft);
  background-color: var(--c-bg-soft);
  padding: 12px 12px;
}

.channel-cell {
  font-size: 14px;
  line-height: 1.7;
}

.channel-table .col-no {
  font-family: var(--font-mono);
  color: var(--c-accent);
}

.channel-table .col-topic {
  font-weight: 600;
  color: var(--c-text);
}

.channel-table .col-focus,
.channel-table .col-audience {
  color: var(--c-text-soft);
}

/* 4.8 频道分类页：条目主题摘要 */
.digest-group {
  padding: 20px 0;
  border-top: 1px solid var(--c-line);
}

.digest-group:first-of-type {
  border-top: 0;
}

.digest-group-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 220px;
  gap: 20px;
  align-items: center;
  margin-bottom: 14px;
}

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

.digest-media {
  margin: 0;
}

.digest-media img {
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-sm);
  background-color: var(--c-bg-soft);
}

.digest-list {
  display: flex;
  flex-direction: column;
}

.digest-item {
  display: grid;
  grid-template-columns: 180px minmax(0, 1fr);
  gap: 6px 20px;
  padding: 12px 0;
  border-top: 1px dashed var(--c-line);
  font-size: 14px;
  line-height: 1.7;
}

.digest-name {
  font-weight: 600;
  color: var(--c-text);
}

.digest-text {
  color: var(--c-text-soft);
}

/* 4.9 频道分类页：侧栏差异说明 */
.diff-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 14px;
}

.diff-item {
  padding-top: 14px;
  border-top: 1px solid var(--c-line);
}

.diff-item:first-child {
  padding-top: 0;
  border-top: 0;
}

.diff-name {
  font-size: 15px;
  font-weight: 600;
}

.diff-text {
  margin-top: 6px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

/* 4.10 专题片单页：专题列表 */
.playlist-list-section .section-title {
  margin-bottom: 8px;
}

.playlist-entry {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: 24px;
  padding: 24px 0;
  border-top: 1px solid var(--c-line);
}

.playlist-entry:first-of-type {
  border-top: 0;
  padding-top: 8px;
}

.playlist-figure {
  margin: 0;
}

.playlist-figure img {
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border: 1px solid var(--c-line);
  border-radius: var(--radius-sm);
  background-color: var(--c-bg-soft);
}

.playlist-body {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.playlist-body .playlist-name {
  font-size: 18px;
}

.playlist-meta {
  display: grid;
  grid-template-columns: 96px minmax(0, 1fr);
  gap: 6px 16px;
  font-size: 14px;
  line-height: 1.7;
}

.playlist-meta dt {
  font-weight: 600;
  color: var(--c-text);
}

.playlist-meta dd {
  color: var(--c-text-soft);
}

/* 4.11 专题片单页：片单顺序说明 */
.order-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--gap-col);
}

.order-column {
  padding: 20px;
  background-color: var(--c-bg-soft);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

.order-subtitle {
  font-size: 16px;
  font-weight: 600;
}

.order-text {
  margin-top: 10px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--c-text-soft);
}

.order-list {
  margin-top: 14px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.order-list li {
  position: relative;
  padding-left: 16px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

.order-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 6px;
  background-color: var(--c-accent);
  border-radius: 50%;
}

/* 4.12 专题片单页：适合人群说明 */
.audience-list {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--c-line);
}

.audience-item {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  gap: 6px 24px;
  padding: 16px 0;
  border-bottom: 1px solid var(--c-line);
}

.audience-name {
  font-size: 15px;
  font-weight: 600;
}

.audience-text {
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

/* 4.13 专题片单页：相关链接 */
.related-links {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.related-item {
  padding: 14px 16px;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  background-color: var(--c-bg);
  transition: border-color 160ms ease, transform 160ms ease;
}

.related-item:hover {
  border-color: var(--c-accent);
  transform: translateY(-1px);
}

.related-item a {
  font-size: 15px;
  font-weight: 600;
}

/* 4.14 观看指南页：准备事项 */
.guide-section {
  padding: 40px 0;
  border-top: 1px solid var(--c-line);
}

.guide-section:first-of-type {
  border-top: 0;
  padding-top: 8px;
}

.guide-figure {
  margin: 24px 0;
}

.prepare-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.prepare-item {
  padding: 18px;
  background-color: var(--c-bg-soft);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

.prepare-name {
  font-size: 16px;
  font-weight: 600;
}

.prepare-text {
  margin-top: 8px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

/* 4.15 观看指南页：入口核验四步 */
.verify-steps {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  counter-reset: verify;
}

.verify-step {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 18px;
  background-color: var(--c-bg);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  transition: border-color 160ms ease, transform 160ms ease, box-shadow 160ms ease;
}

.verify-step:hover {
  border-color: var(--c-accent);
  transform: translateY(-1px);
  box-shadow: var(--shadow-hover);
}

.verify-step .step-index {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-accent);
}

.verify-step .step-name {
  font-size: 16px;
  font-weight: 600;
}

.verify-step .step-text {
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

.verify-step .step-result {
  margin-top: auto;
  padding-top: 10px;
  border-top: 1px dashed var(--c-line);
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-text);
}

/* 4.16 观看指南页：常见问题处理路径 */
.issue-list {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--c-line);
}

.issue-item {
  border-bottom: 1px solid var(--c-line);
}

.issue-summary {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 12px 0;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

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

.issue-summary::before {
  content: "+";
  display: inline-block;
  width: 20px;
  font-family: var(--font-mono);
  font-weight: 400;
  color: var(--c-accent);
}

.issue-item[open] .issue-summary::before {
  content: "−";
}

.issue-summary:hover {
  color: var(--c-accent);
}

.issue-body {
  padding: 0 0 16px 20px;
}

.issue-action {
  font-size: 14px;
  line-height: 1.75;
  color: var(--c-text);
}

.issue-meta {
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

/* 4.17 观看指南页：阅读记录 */
.record-panel {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  padding: 18px;
  background-color: var(--c-bg-soft);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

.record-text {
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

.record-state {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-accent);
}

.record-clear {
  min-height: 44px;
  padding: 0 18px;
  font-size: 14px;
  font-weight: 600;
  color: var(--c-accent);
  background-color: var(--c-bg);
  border: 1px solid var(--c-accent);
  border-radius: var(--radius);
  transition: background-color 160ms ease;
}

.record-clear:hover,
.record-clear:focus-visible {
  background-color: var(--c-accent-soft);
}

/* 4.18 收录边界页：说明范围界定 */
.scope-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--gap-col);
}

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

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

.scope-col-out {
  border-left: 3px solid var(--c-warn);
}

.scope-col-title {
  font-size: 16px;
  font-weight: 600;
}

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

.scope-item {
  position: relative;
  padding-left: 18px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

.scope-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 8px;
  height: 2px;
  background-color: var(--c-text-soft);
}

.scope-item .field-name {
  display: block;
  font-weight: 600;
  color: var(--c-text);
}

/* 4.19 收录边界页：字段口径 */
.field-table {
  border-top: 1px solid var(--c-line);
}

.field-row {
  display: grid;
  grid-template-columns: 160px minmax(0, 1fr);
  gap: 6px 24px;
  padding: 14px 0;
  border-bottom: 1px solid var(--c-line);
}

.field-term {
  font-size: 15px;
  font-weight: 600;
  color: var(--c-text);
}

.field-desc {
  font-size: 14px;
  line-height: 1.75;
  color: var(--c-text-soft);
}

/* 4.20 收录边界页：反馈流程 */
.feedback-flow {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
}

.feedback-step {
  padding: 18px;
  background-color: var(--c-bg-soft);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}

.feedback-step-title {
  font-size: 15px;
  font-weight: 600;
}

.feedback-step-text {
  margin-top: 8px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text-soft);
}

.section-note {
  margin-top: 20px;
  padding: 16px 18px;
  background-color: var(--c-accent-soft);
  border-radius: var(--radius);
}

.note-text {
  font-size: 14px;
  line-height: 1.75;
  color: var(--c-text);
}

/* 4.21 404 页 */
.error-main {
  display: flex;
  justify-content: center;
  padding-top: 64px;
  padding-bottom: 96px;
}

.error-panel {
  max-width: 640px;
  width: 100%;
  text-align: left;
}

.error-code {
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 0.08em;
  color: var(--c-accent);
}

.error-panel h1 {
  margin-top: 12px;
  font-size: 30px;
  font-weight: 600;
}

.error-text {
  margin-top: 14px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-text-soft);
}

.error-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.error-action-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 22px;
  font-size: 15px;
  font-weight: 600;
  color: #ffffff;
  background-color: var(--c-accent);
  border-radius: var(--radius);
}

.error-action-primary:hover,
.error-action-primary:focus-visible {
  color: #ffffff;
  background-color: #185a4a;
}

.error-action-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 4px;
  font-size: 15px;
  font-weight: 600;
}

/* --------------------------------------------------------------------------
   5. responsive —— 960px 与 640px 断点
   -------------------------------------------------------------------------- */

@media (max-width: 960px) {
  .page-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: 32px;
  }

  .sidebar {
    padding-top: 24px;
    border-top: 1px solid var(--c-line);
  }

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

  .hero-media {
    order: -1;
  }

  .step-list,
  .verify-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .index-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .channel-table .channel-row {
    grid-template-columns: 56px minmax(0, 1fr) minmax(0, 1fr);
  }

  .channel-table .col-audience {
    grid-column: 2 / -1;
  }

  .playlist-entry {
    grid-template-columns: 220px minmax(0, 1fr);
    gap: 20px;
  }

  .digest-group-head {
    grid-template-columns: minmax(0, 1fr) 180px;
  }
}

@media (max-width: 640px) {
  .fact-bar {
    flex-direction: column;
    align-items: flex-start;
    padding: 10px 16px;
  }

  .header-inner {
    padding: 10px 16px;
    gap: 0;
  }

  .nav-toggle {
    display: flex;
  }

  .site-nav {
    width: 100%;
    margin-left: 0;
    flex-basis: 100%;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    margin-top: 10px;
    border-top: 1px solid var(--c-line);
  }

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

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

  .nav-link {
    display: flex;
    align-items: center;
    min-height: 44px;
    padding: 10px 4px;
    border-bottom: 0;
    border-left: 2px solid transparent;
    border-radius: 0;
  }

  .nav-link.is-current {
    border-bottom: 0;
    border-left-color: var(--c-accent);
    padding-left: 10px;
  }

  .site-main {
    padding: 0 16px 56px;
  }

  .page-header {
    padding-bottom: 18px;
    margin-bottom: 24px;
  }

  .page-title,
  .hero-title,
  .error-panel h1 {
    font-size: 24px;
  }

  .section {
    padding: 32px 0;
  }

  .hero {
    padding-top: 28px;
  }

  .hero-actions .btn {
    flex: 1 1 auto;
  }

  .hero-table {
    padding: 16px;
  }

  .quick-table th,
  .quick-table td {
    padding: 8px 10px;
    font-size: 13px;
  }

  .channel-row {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .playlist-grid,
  .step-list,
  .verify-steps,
  .prepare-list,
  .order-columns,
  .scope-columns {
    grid-template-columns: minmax(0, 1fr);
  }

  .index-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .channel-table .channel-row {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  .channel-table .channel-row-head {
    display: none;
  }

  .channel-table .col-no {
    font-size: 13px;
  }

  .channel-table .col-audience {
    grid-column: auto;
  }

  .digest-group-head {
    grid-template-columns: minmax(0, 1fr);
  }

  .digest-item,
  .audience-item,
  .field-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 4px;
  }

  .playlist-entry {
    grid-template-columns: minmax(0, 1fr);
    gap: 16px;
  }

  .playlist-meta {
    grid-template-columns: 84px minmax(0, 1fr);
  }

  .record-panel {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-inner {
    padding: 32px 16px 20px;
  }

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

  .footer-cta-link {
    width: 100%;
    justify-content: center;
  }

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

  .error-main {
    padding-top: 40px;
    padding-bottom: 64px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}