/* ============================================================
   九九影视 · 全站样式表
   站点：zhizhaibao.cn
   结构：base / layout / components / pages / responsive
   ============================================================ */

/* ------------------------------------------------------------
   base · 基础与变量
   ------------------------------------------------------------ */
:root {
  --paper: #FBFBF9;
  --ink: #17181A;
  --accent: #2F5BFF;
  --accent-deep: #1E42C8;
  --muted: #6B6F76;
  --line: #E4E5E2;
  --ink-soft: #2A2C30;
  --footer-bg: #17181A;
  --footer-ink: #C9CBD0;
  --footer-title: #F2F3F5;
  --radius: 6px;
  --radius-sm: 4px;
  --shell: 1120px;
  --shadow-card: 0 1px 2px rgba(23, 24, 26, 0.04);
  --shadow-raise: 0 6px 18px rgba(23, 24, 26, 0.08);
}

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

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

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

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

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

h1,
h2,
h3,
h4 {
  margin: 0;
  color: var(--ink);
  font-weight: 700;
  line-height: 1.35;
}

p {
  margin: 0;
}

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

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

figure {
  margin: 0;
}

figcaption {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.7;
}

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

/* ------------------------------------------------------------
   layout · 页面骨架
   ------------------------------------------------------------ */

/* 顶部信息条 */
.top-bar {
  background: var(--ink);
  color: #EDEEF0;
}

.top-bar-text {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 9px 24px;
  font-size: 13px;
  line-height: 1.6;
  color: #D6D8DC;
}

/* 页头 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(251, 251, 249, 0.96);
  border-bottom: 1px solid var(--line);
  backdrop-filter: saturate(160%) blur(6px);
}

.header-inner {
  position: relative;
  display: flex;
  align-items: center;
  gap: 20px;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 14px 24px;
}

.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  color: var(--ink);
  font-weight: 700;
  white-space: nowrap;
}

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

.brand-mark {
  font-size: 20px;
  letter-spacing: 0.02em;
}

.brand-sub {
  color: var(--muted);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.04em;
}

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

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

.nav-item {
  display: block;
}

.nav-link {
  display: inline-block;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  color: var(--ink-soft);
  font-size: 15px;
  line-height: 1.4;
  transition: background-color 0.18s ease, color 0.18s ease;
}

.nav-link:hover,
.nav-link:focus-visible {
  background: #F1F2F4;
  color: var(--ink);
}

.nav-link.is-current {
  color: var(--accent);
  font-weight: 700;
}

/* 命令面板按钮 */
.command-trigger {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 10px 7px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FFFFFF;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.4;
  transition: border-color 0.18s ease, color 0.18s ease, box-shadow 0.18s ease;
}

.command-trigger:hover,
.command-trigger:focus-visible {
  border-color: #C9CBD0;
  color: var(--ink);
  box-shadow: var(--shadow-card);
}

.command-trigger-key {
  padding: 1px 6px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: #F6F6F4;
  color: var(--muted);
  font-size: 11px;
  letter-spacing: 0.06em;
}

/* 命令面板 */
.command-palette {
  position: absolute;
  top: calc(100% + 8px);
  right: 24px;
  width: 340px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FFFFFF;
  box-shadow: var(--shadow-raise);
}

.command-palette[hidden] {
  display: none;
}

.command-field {
  display: block;
}

.command-field-label {
  display: block;
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0.04em;
}

.command-input {
  width: 100%;
  padding: 9px 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: #FCFCFA;
  color: var(--ink);
  font-size: 14px;
  line-height: 1.5;
}

.command-input::placeholder {
  color: #A5A9AF;
}

.command-results {
  margin-top: 10px;
}

.command-result a {
  display: block;
  padding: 8px 10px;
  border-radius: var(--radius-sm);
  color: var(--ink-soft);
  font-size: 14px;
}

.command-result a:hover,
.command-result a:focus-visible {
  background: #F1F2F4;
  color: var(--accent);
}

.command-empty {
  margin-top: 10px;
  padding: 8px 10px;
  color: var(--muted);
  font-size: 13px;
}

.command-empty[hidden] {
  display: none;
}

/* 汉堡按钮（桌面隐藏） */
.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FFFFFF;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
}

.nav-toggle-bar {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--ink);
  border-radius: 1px;
}

/* 主内容容器 */
.site-main {
  display: block;
}

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

/* 面包屑 */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 18px;
  color: var(--muted);
  font-size: 13px;
}

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

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

.breadcrumb-sep {
  color: #B9BCC2;
}

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

/* 内页标题区 */
.page-header {
  padding-bottom: 22px;
  margin-bottom: 34px;
  border-bottom: 1px solid var(--line);
}

.page-title {
  font-size: 34px;
  font-weight: 700;
  color: var(--ink);
}

.page-description {
  max-width: 760px;
  margin-top: 12px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.8;
}

/* 页脚 */
.site-footer {
  background: var(--footer-bg);
  color: var(--footer-ink);
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1.4fr;
  gap: 40px;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 48px 24px 32px;
}

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

.footer-brand-name {
  color: var(--footer-title);
  font-size: 17px;
  font-weight: 700;
}

.footer-brand-desc {
  margin-top: 10px;
  color: var(--footer-ink);
  font-size: 14px;
  line-height: 1.8;
}

.footer-title {
  margin-bottom: 14px;
  color: var(--footer-title);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
}

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

.footer-list a {
  color: var(--footer-ink);
  font-size: 14px;
}

.footer-list a:hover,
.footer-list a:focus-visible {
  color: #FFFFFF;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.footer-boundary-text {
  color: var(--footer-ink);
  font-size: 14px;
  line-height: 1.8;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-copy {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 16px 24px 22px;
  color: #8F9299;
  font-size: 13px;
}

/* ------------------------------------------------------------
   components · 通用组件
   ------------------------------------------------------------ */

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 22px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 600;
  line-height: 1.4;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease, transform 0.18s ease;
}

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

.btn-primary:hover,
.btn-primary:focus-visible {
  background: var(--accent-deep);
  color: #FFFFFF;
  transform: translateY(-1px);
}

.btn-ghost {
  border-color: #C9CBD0;
  background: transparent;
  color: var(--ink);
}

.btn-ghost:hover,
.btn-ghost:focus-visible {
  border-color: var(--ink);
  color: var(--ink);
  transform: translateY(-1px);
}

/* 通用 section */
.section {
  margin-bottom: 56px;
}

.section-head {
  margin-bottom: 22px;
}

.section-title {
  font-size: 22px;
  font-weight: 700;
  color: var(--ink);
}

.section-desc {
  max-width: 780px;
  margin-top: 8px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.8;
}

.section-intro {
  max-width: 780px;
  margin-top: 8px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.8;
}

.section-foot {
  margin-top: 18px;
  font-size: 14px;
}

.section-figure {
  margin-top: 26px;
}

.section-figure img {
  width: 100%;
  max-height: 380px;
  border-radius: var(--radius);
  object-fit: cover;
  background: #EFEFEC;
}

.section-figure figcaption {
  margin-top: 8px;
}

/* 字段说明表 */
.field-table {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FFFFFF;
  font-size: 14px;
}

.field-table-caption {
  padding: 10px 14px;
  color: var(--muted);
  font-size: 13px;
  text-align: left;
}

.field-table th,
.field-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
  line-height: 1.75;
}

.field-table thead th {
  background: #F5F5F3;
  color: var(--ink);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.field-table tbody th {
  width: 26%;
  color: var(--ink);
  font-weight: 600;
}

.field-table tbody td {
  color: var(--ink-soft);
}

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

/* 边界说明列表（通用） */
.boundary-item {
  padding-left: 16px;
  border-left: 2px solid var(--accent);
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.8;
}

.boundary-item + .boundary-item {
  margin-top: 12px;
}

/* 下一步链接列表（专题 / 反馈共用） */
.next-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 12px;
}

.next-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FFFFFF;
  transition: border-color 0.18s ease, transform 0.18s ease, box-shadow 0.18s ease;
}

.next-item:hover,
.next-item:focus-within {
  border-color: #C9CBD0;
  transform: translateY(-2px);
  box-shadow: var(--shadow-card);
}

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

.next-desc {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.7;
}

/* ------------------------------------------------------------
   pages · 首页
   ------------------------------------------------------------ */
.home-main {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 40px 24px 72px;
}

/* 首屏媒体焦点区 */
.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 44px;
  align-items: start;
  padding-bottom: 48px;
  margin-bottom: 56px;
  border-bottom: 1px solid var(--line);
}

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

.hero-eyebrow {
  color: var(--accent);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.hero-title {
  margin-top: 12px;
  font-size: 40px;
  font-weight: 700;
  line-height: 1.25;
  color: var(--ink);
}

.hero-lead {
  max-width: 560px;
  margin-top: 16px;
  color: var(--ink-soft);
  font-size: 16px;
  line-height: 1.85;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 20px;
}

.hero-tag {
  padding: 5px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #FFFFFF;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

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

.hero-media img {
  width: 100%;
  aspect-ratio: 4 / 3;
  border-radius: var(--radius);
  object-fit: cover;
  background: #EFEFEC;
}

.hero-caption {
  margin-top: 10px;
}

/* 频道索引总览 */
.channel-index {
  border-top: 1px solid var(--line);
}

.channel-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.section-channels .channel-name {
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
}

.channel-field {
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.8;
}

.field-label {
  display: inline-block;
  min-width: 76px;
  color: var(--muted);
  font-size: 13px;
}

/* 专题片单入口 */
.special-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

.special-card {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FFFFFF;
  overflow: hidden;
  transition: border-color 0.18s ease, transform 0.18s ease, box-shadow 0.18s ease;
}

.special-card:hover {
  border-color: #C9CBD0;
  transform: translateY(-2px);
  box-shadow: var(--shadow-card);
}

.special-media img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: #EFEFEC;
}

.special-body {
  padding: 16px 18px 20px;
}

.special-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

.special-scope {
  margin-top: 8px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.8;
}

.special-count {
  margin-top: 10px;
  color: var(--muted);
  font-size: 13px;
}

/* 视频卡片墙 */
.video-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.video-card {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FFFFFF;
  overflow: hidden;
  transition: border-color 0.18s ease, transform 0.18s ease, box-shadow 0.18s ease;
}

.video-card:hover {
  border-color: #C9CBD0;
  transform: translateY(-2px);
  box-shadow: var(--shadow-card);
}

.video-media img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: #EFEFEC;
}

.video-body {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px 16px 18px;
}

.video-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.video-channel {
  color: var(--accent);
  font-size: 13px;
  font-weight: 600;
}

.video-desc {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

/* 观看指引与收录边界摘要 */
.summary-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  gap: 32px;
  align-items: start;
}

.summary-column {
  min-width: 0;
}

.summary-subtitle {
  margin-bottom: 14px;
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
}

.summary-side .boundary-list {
  margin-bottom: 16px;
}

.summary-foot {
  font-size: 14px;
}

/* 站内页面索引 */
.page-index {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 20px;
}

.page-index-item {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FFFFFF;
  transition: border-color 0.18s ease, transform 0.18s ease, box-shadow 0.18s ease;
}

.page-index-item:hover {
  border-color: #C9CBD0;
  transform: translateY(-2px);
  box-shadow: var(--shadow-card);
}

.page-index-title {
  font-size: 16px;
  font-weight: 700;
}

.page-index-title a {
  color: var(--ink);
}

.page-index-title a:hover,
.page-index-title a:focus-visible {
  color: var(--accent);
}

.page-index-desc {
  margin-top: 8px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

/* ------------------------------------------------------------
   pages · 频道分类
   ------------------------------------------------------------ */
.channel-rows {
  border-top: 1px solid var(--line);
}

.section-channel-table .channel-row {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr) minmax(0, 1fr);
  gap: 18px;
  align-items: start;
  padding: 20px 0;
  border-bottom: 1px solid var(--line);
}

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

.section-channel-table .channel-name {
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

.channel-topic {
  margin-top: 6px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.channel-org,
.channel-sample {
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.8;
}

/* 频道内浏览顺序建议 */
.order-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.order-column {
  min-width: 0;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FFFFFF;
}

.order-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

.order-desc {
  margin-top: 8px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.order-list {
  margin-top: 14px;
}

.order-list li {
  position: relative;
  padding-left: 16px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.8;
}

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

.order-list li::before {
  content: "";
  position: absolute;
  top: 11px;
  left: 0;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}

/* 相关入口 */
.related-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}

.related-item {
  padding: 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FFFFFF;
  transition: border-color 0.18s ease, transform 0.18s ease, box-shadow 0.18s ease;
}

.related-item:hover {
  border-color: #C9CBD0;
  transform: translateY(-2px);
  box-shadow: var(--shadow-card);
}

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

.related-desc {
  margin-top: 6px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

/* ------------------------------------------------------------
   pages · 专题片单
   ------------------------------------------------------------ */
.topic-intro {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: 32px;
  align-items: start;
}

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

.topic-figure img {
  width: 100%;
  aspect-ratio: 4 / 3;
  border-radius: var(--radius);
  object-fit: cover;
  background: #EFEFEC;
}

.topic-figure-caption {
  margin-top: 10px;
}

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

.topic-point + .topic-point {
  margin-top: 18px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.topic-point-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

.topic-point-text {
  margin-top: 6px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.85;
}

/* 片单结构示例 */
.playlist-list {
  border-top: 1px solid var(--line);
}

.playlist-item {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.playlist-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: #F1F2F4;
  color: var(--ink);
  font-size: 14px;
  font-weight: 700;
}

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

.playlist-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.playlist-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 6px;
}

.playlist-tag {
  padding: 2px 10px;
  border-radius: 999px;
  background: #EEF1FF;
  color: var(--accent-deep);
  font-size: 12px;
  font-weight: 600;
}

.playlist-duration {
  color: var(--muted);
  font-size: 13px;
}

.playlist-text {
  margin-top: 8px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.playlist-note {
  margin-top: 16px;
  font-size: 14px;
}

/* 专题与频道的区别 */
.compare-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px;
}

.compare-col {
  min-width: 0;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FFFFFF;
}

.compare-col-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

.compare-col-text {
  margin-top: 8px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.85;
}

.compare-list {
  margin-top: 14px;
}

.compare-list li {
  position: relative;
  padding-left: 16px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

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

.compare-list li::before {
  content: "";
  position: absolute;
  top: 11px;
  left: 0;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}

/* ------------------------------------------------------------
   pages · 观看指引
   ------------------------------------------------------------ */
.guide-section {
  margin-bottom: 48px;
}

.guide-figure {
  margin: 20px 0 24px;
}

.guide-figure img {
  width: 100%;
  max-height: 340px;
  border-radius: var(--radius);
  object-fit: cover;
  background: #EFEFEC;
}

.guide-figure figcaption {
  margin-top: 8px;
}

/* 设备与网络准备 */
.prepare-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 18px;
}

.prepare-item {
  min-width: 0;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FFFFFF;
}

.prepare-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.prepare-desc {
  margin-top: 8px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

/* 入口核验步骤 */
.step-list {
  border-top: 1px solid var(--line);
  counter-reset: step;
}

.step-item {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  grid-template-rows: auto auto;
  column-gap: 14px;
  align-items: center;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.step-index {
  grid-row: 1 / span 2;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--accent);
  color: #FFFFFF;
  font-size: 14px;
  font-weight: 700;
}

.step-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.step-desc {
  grid-column: 2;
  margin-top: 4px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

/* 常见问题 */
.faq-group {
  border-top: 1px solid var(--line);
}

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

.faq-question {
  position: relative;
  padding: 16px 40px 16px 0;
  color: var(--ink);
  font-size: 16px;
  font-weight: 600;
  line-height: 1.7;
  cursor: pointer;
  list-style: none;
}

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

.faq-question::after {
  content: "+";
  position: absolute;
  top: 14px;
  right: 4px;
  color: var(--muted);
  font-size: 20px;
  font-weight: 400;
  line-height: 1;
}

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

.faq-answer {
  padding: 0 40px 18px 0;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.85;
}

/* 本站能力边界 */
.guide-boundary .boundary-item {
  padding: 16px 18px 16px 20px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  background: #FFFFFF;
}

.guide-boundary .boundary-item + .boundary-item {
  margin-top: 12px;
}

.boundary-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.boundary-desc {
  margin-top: 6px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.boundary-note {
  margin-top: 16px;
  font-size: 14px;
}

/* 相关入口 */
.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px;
}

.related-card {
  min-width: 0;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FFFFFF;
  transition: border-color 0.18s ease, transform 0.18s ease, box-shadow 0.18s ease;
}

.related-card:hover {
  border-color: #C9CBD0;
  transform: translateY(-2px);
  box-shadow: var(--shadow-card);
}

.related-name {
  font-size: 16px;
  font-weight: 700;
}

.related-name a {
  color: var(--ink);
}

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

/* ------------------------------------------------------------
   pages · 问题反馈
   ------------------------------------------------------------ */
.page-figure {
  margin-bottom: 34px;
}

.page-figure img {
  width: 100%;
  max-height: 320px;
  border-radius: var(--radius);
  object-fit: cover;
  background: #EFEFEC;
}

.page-figure figcaption {
  margin-top: 8px;
}

/* 可反馈的问题类型 */
.feedback-group-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.feedback-group {
  min-width: 0;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FFFFFF;
}

.feedback-group-title {
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

.feedback-group-desc {
  margin-top: 8px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.feedback-group-list-items {
  margin-top: 14px;
}

.feedback-group-list-items li {
  position: relative;
  padding-left: 16px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.8;
}

.feedback-group-list-items li + li {
  margin-top: 8px;
}

.feedback-group-list-items li::before {
  content: "";
  position: absolute;
  top: 11px;
  left: 0;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}

/* 处理方式与预期 */
.process-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px;
}

.process-item {
  min-width: 0;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FFFFFF;
}

.process-item-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.process-item-desc {
  margin-top: 8px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.section-note {
  margin-top: 18px;
  color: var(--muted);
  font-size: 14px;
}

.section-note a + a {
  margin-left: 14px;
}

/* ------------------------------------------------------------
   pages · 404
   ------------------------------------------------------------ */
.error-main {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 64px 24px 80px;
}

.error-panel {
  max-width: 640px;
  padding-bottom: 40px;
  border-bottom: 1px solid var(--line);
}

.error-code {
  color: var(--accent);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.12em;
}

.error-title {
  margin-top: 12px;
  font-size: 34px;
  font-weight: 700;
  color: var(--ink);
}

.error-text {
  margin-top: 14px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.85;
}

.error-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.error-links {
  margin-top: 44px;
}

.error-links-title {
  font-size: 20px;
  font-weight: 700;
  color: var(--ink);
}

.error-link-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 14px;
  margin-top: 18px;
}

.error-link-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #FFFFFF;
}

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

.error-link-desc {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.7;
}

/* ------------------------------------------------------------
   responsive · 断点
   ------------------------------------------------------------ */

/* 960px 以下：抽屉导航与单列 */
@media (max-width: 960px) {
  .header-inner {
    flex-wrap: wrap;
    gap: 12px;
    padding: 12px 20px;
  }

  .brand-sub {
    display: none;
  }

  .nav-toggle {
    display: inline-flex;
    margin-left: auto;
  }

  .site-nav {
    order: 4;
    width: 100%;
    margin-left: 0;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    margin-top: 8px;
    padding: 8px;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: #FFFFFF;
    box-shadow: var(--shadow-card);
  }

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

  .nav-link {
    display: block;
    padding: 12px 14px;
    font-size: 16px;
  }

  .command-trigger {
    order: 3;
  }

  .command-palette {
    right: 20px;
    left: 20px;
    width: auto;
  }

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

  .hero-title {
    font-size: 30px;
  }

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

  .summary-layout,
  .topic-intro {
    grid-template-columns: minmax(0, 1fr);
    gap: 26px;
  }

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

  .section-channel-table .channel-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 8px;
  }

  .order-columns,
  .compare-grid,
  .feedback-group-list {
    grid-template-columns: minmax(0, 1fr);
  }

  .footer-inner {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 32px;
    padding: 40px 20px 28px;
  }

  .footer-copy {
    padding: 16px 20px 22px;
  }
}

/* 640px 以下：单列与紧凑排版 */
@media (max-width: 640px) {
  body {
    font-size: 15px;
  }

  .top-bar-text {
    padding: 8px 16px;
    font-size: 12px;
  }

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

  .brand-mark {
    font-size: 18px;
  }

  .command-trigger-label {
    display: none;
  }

  .inner-main {
    padding: 18px 16px 56px;
  }

  .home-main {
    padding: 28px 16px 56px;
  }

  .page-title,
  .error-title {
    font-size: 26px;
  }

  .page-header {
    padding-bottom: 18px;
    margin-bottom: 26px;
  }

  .hero {
    padding-bottom: 32px;
    margin-bottom: 40px;
  }

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

  .hero-lead {
    font-size: 15px;
  }

  .section {
    margin-bottom: 40px;
  }

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

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

  .special-cards,
  .prepare-list,
  .process-list,
  .related-list,
  .related-grid,
  .next-list,
  .error-link-list {
    grid-template-columns: minmax(0, 1fr);
  }

  .playlist-item,
  .step-item {
    grid-template-columns: 36px minmax(0, 1fr);
    gap: 12px;
  }

  .step-desc {
    grid-column: 2;
  }

  .field-table th,
  .field-table td {
    padding: 10px 12px;
    font-size: 13px;
  }

  .field-table tbody th {
    width: 34%;
  }

  .field-label {
    display: block;
    min-width: 0;
  }

  .error-main {
    padding: 40px 16px 64px;
  }

  .footer-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 26px;
    padding: 32px 16px 24px;
  }

  .footer-copy {
    padding: 14px 16px 20px;
  }
}