/* ==========================================================================
   天美高清 · 全站样式
   分组：base / layout / components / pages / responsive
   ========================================================================== */

/* --------------------------------------------------------------------------
   base
   -------------------------------------------------------------------------- */

:root {
  --ink: #111214;
  --ink-soft: #5F5B57;
  --ink-meta: #8C857F;
  --paper: #FFFFFF;
  --paper-warm: #F6F4F1;
  --line: #E3DFDA;
  --accent: #E8461B;
  --mono: "SFMono-Regular", "Menlo", "Consolas", "Liberation Mono", monospace;
  --shell: 1180px;
  --shell-narrow: 780px;
  --radius: 3px;
  --header-h: 64px;
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h) + 16px);
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC", sans-serif;
  font-size: 16px;
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3,
h4 {
  margin: 0;
  font-weight: 700;
  line-height: 1.4;
  color: var(--ink);
}

h1 {
  font-size: 34px;
  line-height: 1.3;
}

h2 {
  font-size: 24px;
  line-height: 1.4;
}

h3 {
  font-size: 18px;
  line-height: 1.5;
}

p {
  margin: 0;
}

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

ul,
ol {
  list-style: none;
}

a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 160ms ease, border-color 160ms ease;
}

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

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

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

figure {
  margin: 0;
}

figcaption {
  font-size: 13px;
  line-height: 1.6;
  color: var(--ink-meta);
  margin-top: 8px;
}

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

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 15px;
}

caption {
  text-align: left;
  font-size: 13px;
  color: var(--ink-meta);
  padding-bottom: 8px;
}

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

th {
  font-weight: 700;
  font-size: 14px;
  color: var(--ink);
  background: var(--paper-warm);
  border-bottom: 1px solid var(--line);
}

.mono {
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0.04em;
}

/* 仅供读屏与语义保留的表题，正常可见且不裁切 */
.visually-plain {
  display: block;
  width: auto;
  height: auto;
  overflow: visible;
  white-space: normal;
  text-align: left;
  font-size: 13px;
  line-height: 1.6;
  color: var(--ink-meta);
  padding: 0 0 10px;
}

/* --------------------------------------------------------------------------
   layout · 全站骨架
   -------------------------------------------------------------------------- */

.site-body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

.inner-main {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 24px 72px;
}

.home-main {
  padding-bottom: 0;
}

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

.header-inner {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 24px;
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 24px;
}

.brand {
  flex: 0 0 auto;
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--ink);
  border-bottom: 0;
  padding: 4px 0;
}

.brand:hover {
  color: var(--ink);
  border-bottom: 0;
}

/* 主导航 */
.main-nav.site-nav {
  flex: 1 1 auto;
  min-width: 0;
}

.nav-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px 22px;
}

.nav-list li {
  flex: 0 0 auto;
}

.nav-link {
  display: inline-block;
  padding: 8px 0;
  font-size: 15px;
  color: var(--ink-soft);
  border-bottom: 2px solid transparent;
  transition: color 160ms ease, border-color 160ms ease;
}

.nav-link:hover {
  color: var(--ink);
  border-bottom-color: var(--accent);
}

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

/* 通知胶囊按钮 */
.notice-toggle {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 34px;
  padding: 0 14px;
  font-size: 13px;
  color: var(--ink-soft);
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--paper);
  transition: border-color 160ms ease, color 160ms ease;
}

.notice-toggle::after {
  content: "通知";
}

.notice-toggle:hover {
  color: var(--ink);
  border-color: var(--ink-meta);
}

.notice-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
  flex: 0 0 auto;
}

/* 通知面板 */
.notice-panel {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 14px 24px 16px;
  border-bottom: 1px solid var(--line);
  background: var(--paper-warm);
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
}

.notice-panel p {
  margin-bottom: 6px;
}

.notice-panel a {
  color: var(--ink);
  border-bottom: 1px solid var(--accent);
}

.notice-panel a:hover {
  color: var(--accent);
}

/* 汉堡按钮 */
.menu-toggle {
  display: none;
  flex: 0 0 auto;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.menu-bar {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--ink);
}

/* 移动导航 */
.mobile-nav {
  border-bottom: 1px solid var(--line);
  background: var(--paper);
}

.mobile-nav-list {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 8px 24px 16px;
}

.mobile-nav-list li a {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0 4px;
  font-size: 16px;
  color: var(--ink);
  border-bottom: 1px solid var(--line);
}

.mobile-nav-list li:last-child a {
  border-bottom: 0;
}

.mobile-nav-list li a:hover {
  color: var(--accent);
  border-bottom-color: var(--line);
}

/* 面包屑 */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 20px 0 4px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--ink-meta);
}

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

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

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

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

/* 页面标题区 */
.page-header {
  padding: 10px 0 26px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 34px;
}

.page-title {
  font-size: 34px;
  line-height: 1.3;
  font-weight: 700;
  color: var(--ink);
}

.page-lead {
  margin-top: 14px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--ink-soft);
  max-width: 62ch;
}

.page-meta {
  margin-top: 10px;
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--ink-meta);
}

/* 页脚 */
.site-footer {
  flex: 0 0 auto;
  background: var(--paper-warm);
  border-top: 1px solid var(--line);
  margin-top: 0;
}

.footer-inner {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 48px 24px 32px;
  display: grid;
  grid-template-columns: minmax(220px, 1.6fr) repeat(4, minmax(120px, 1fr));
  gap: 32px 28px;
}

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

.footer-logo {
  display: inline-block;
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
  border-bottom: 0;
}

.footer-logo:hover {
  color: var(--accent);
  border-bottom: 0;
}

.footer-intro {
  margin-top: 12px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-soft);
  max-width: 30ch;
}

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

.footer-col h3 {
  font-size: 14px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 12px;
  letter-spacing: 0.02em;
}

.footer-col ul li {
  margin-bottom: 2px;
}

.footer-col ul li a {
  display: inline-block;
  padding: 5px 0;
  font-size: 14px;
  line-height: 1.6;
  color: var(--ink-soft);
}

.footer-col ul li a:hover {
  color: var(--accent);
}

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

.footer-bottom p {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 18px 24px 26px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-meta);
}

/* 通用内容宽度 */
.page-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 48px;
  align-items: start;
}

.page-layout.layout-shell {
  grid-template-columns: minmax(0, 1fr) 300px;
}

.page-layout.narrow-layout {
  display: block;
  max-width: var(--shell-narrow);
  margin: 0 auto;
}

.page-primary,
.layout-main,
.report-body {
  min-width: 0;
}

/* 右侧栏：aside 在后，贴顶 */
.layout-side,
.related,
.stuck-points {
  min-width: 0;
  position: sticky;
  top: calc(var(--header-h) + 20px);
}

/* 左侧栏：aside 在前 */
.sidebar-left {
  grid-template-columns: 260px minmax(0, 1fr);
}

.sidebar-left .report-toc {
  position: sticky;
  top: calc(var(--header-h) + 20px);
  min-width: 0;
}

/* 区块通用 */
.section-head {
  margin-bottom: 22px;
}

.section-head h2 {
  margin-bottom: 8px;
}

.section-lead,
.section-intro {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
  max-width: 64ch;
}

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

.section-more {
  margin-top: 22px;
  font-size: 15px;
}

.section-more a {
  color: var(--ink);
  border-bottom: 1px solid var(--accent);
  padding-bottom: 1px;
}

.section-more a:hover {
  color: var(--accent);
}

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

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 22px;
  font-size: 15px;
  font-weight: 700;
  border-radius: var(--radius);
  border: 1px solid transparent;
  transition: background-color 160ms ease, color 160ms ease, border-color 160ms ease;
}

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

.btn-primary:hover {
  background: #C93A14;
  border-color: #C93A14;
  color: #FFFFFF;
}

.btn-ghost {
  background: transparent;
  color: #FFFFFF;
  border-color: rgba(255, 255, 255, 0.7);
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.14);
  border-color: #FFFFFF;
  color: #FFFFFF;
}

/* 侧栏面板 */
.side-panel,
.related-panel {
  background: var(--paper-warm);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px 20px 22px;
  margin-bottom: 20px;
}

.side-panel h2,
.related-panel h2,
.side-title {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 12px;
  letter-spacing: 0.02em;
}

.side-anchor-list li,
.related-links li {
  border-top: 1px solid var(--line);
}

.side-anchor-list li:first-child,
.related-links li:first-child {
  border-top: 0;
}

.side-anchor-list li a,
.related-links li a {
  display: block;
  padding: 9px 0;
  font-size: 14px;
  line-height: 1.6;
  color: var(--ink-soft);
}

.side-anchor-list li a:hover,
.related-links li a:hover {
  color: var(--accent);
}

.side-panel-note p,
.related-note p {
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink-soft);
  margin-bottom: 10px;
}

.side-link {
  display: inline-block;
  font-size: 14px;
  color: var(--ink);
  border-bottom: 1px solid var(--accent);
}

.side-link:hover {
  color: var(--accent);
}

/* 折叠问答 */
.faq-item {
  border-bottom: 1px solid var(--line);
}

.faq-item summary {
  position: relative;
  display: block;
  padding: 15px 34px 15px 16px;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.6;
  color: var(--ink);
  cursor: pointer;
  list-style: none;
  border-left: 3px solid transparent;
  transition: border-color 160ms ease, color 160ms ease;
}

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

.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--mono);
  font-size: 18px;
  color: var(--ink-meta);
}

.faq-item[open] summary {
  border-left-color: var(--accent);
  color: var(--accent);
}

.faq-item[open] summary::after {
  content: "−";
  color: var(--accent);
}

.faq-item summary:hover {
  color: var(--accent);
}

.faq-item > p,
.faq-answer {
  padding: 0 34px 14px 16px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.faq-answer p {
  margin-bottom: 8px;
}

.faq-next {
  font-size: 14px;
}

.faq-next a {
  color: var(--ink);
  border-bottom: 1px solid var(--accent);
}

.faq-next a:hover {
  color: var(--accent);
}

/* 定义列表 */
.field-list {
  border-top: 1px solid var(--line);
}

.field-row {
  display: grid;
  grid-template-columns: 160px minmax(0, 1fr);
  gap: 8px 24px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.field-row dt {
  font-weight: 700;
  font-size: 15px;
  color: var(--ink);
}

.field-row dd {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
  min-width: 0;
}

.field-req,
.field-err {
  display: block;
  font-size: 14px;
  line-height: 1.7;
}

.field-err {
  color: var(--ink-meta);
  margin-top: 4px;
}

/* 表格来源标注 */
.table-source {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-meta);
}

/* 下一步链接列表 */
.next-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  margin-top: 16px;
}

.next-links li a {
  display: inline-block;
  padding: 8px 14px;
  font-size: 14px;
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
}

.next-links li a:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* --------------------------------------------------------------------------
   pages · 首页
   -------------------------------------------------------------------------- */

/* 通知条 */
.notice {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  background: var(--ink);
  color: #EDEAE6;
}

.notice-text {
  flex: 1 1 auto;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 10px 0 10px 24px;
  font-size: 13px;
  line-height: 1.7;
}

.notice-text a {
  color: #FFFFFF;
  border-bottom: 1px solid var(--accent);
}

.notice-text a:hover {
  color: var(--accent);
}

.notice-close {
  flex: 0 0 auto;
  width: 44px;
  min-height: 44px;
  font-size: 18px;
  line-height: 1;
  color: #EDEAE6;
  margin-left: auto;
}

.notice-close::before {
  content: "×";
}

.notice-close:hover {
  color: var(--accent);
}

/* 全宽焦点区 */
.focus {
  position: relative;
  background: var(--ink);
}

.focus-media {
  position: relative;
  margin: 0;
  max-width: 1440px;
  margin-left: auto;
  margin-right: auto;
}

.focus-media img {
  width: 100%;
  height: clamp(360px, 46vw, 560px);
  object-fit: cover;
  object-position: center;
}

.focus-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(17, 18, 20, 0.62);
  pointer-events: none;
}

.focus-caption {
  position: absolute;
  inset: 0;
  z-index: 2;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 18px;
  max-width: var(--shell);
  width: 100%;
  margin: 0 auto;
  padding: 0 24px;
  color: #FFFFFF;
}

.focus-caption h1 {
  font-size: 40px;
  line-height: 1.25;
  font-weight: 700;
  color: #FFFFFF;
  max-width: 20ch;
  margin: 0;
}

.focus-lead {
  font-size: 16px;
  line-height: 1.8;
  color: #E6E2DD;
  max-width: 46ch;
}

.focus-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 4px;
}

/* 快速入口条 */
.quick-entry {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 24px;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  border-bottom: 1px solid var(--line);
}

.entry-cell {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 22px 18px;
  border-left: 1px solid var(--line);
  border-bottom: 0;
  transition: background-color 160ms ease, border-color 160ms ease;
}

.entry-cell:first-child {
  border-left: 0;
}

.entry-cell:hover {
  background: var(--paper-warm);
  border-bottom: 0;
  color: var(--ink);
}

.entry-num {
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--accent);
}

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

.entry-desc {
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-soft);
}

/* 首页各区块通用容器 */
.channel-summary,
.feature-preview,
.quality-summary,
.steps-preview,
.faq-center,
.standard-summary {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 56px 24px;
}

.channel-summary,
.steps-preview,
.standard-summary {
  border-bottom: 1px solid var(--line);
}

/* 频道索引摘要 */
.channel-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.channel-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px 20px 18px 24px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-left: 3px solid var(--line);
  border-radius: var(--radius);
  min-width: 0;
  transition: transform 160ms ease, border-color 160ms ease;
}

.channel-card:hover {
  transform: translateY(-2px);
  border-left-color: var(--accent);
}

.channel-mark {
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: transparent;
}

.channel-card h3 {
  font-size: 18px;
  line-height: 1.5;
}

.channel-card > p {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.channel-samples {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 10px;
  margin-top: 2px;
}

.channel-samples li {
  font-size: 13px;
  line-height: 1.6;
  color: var(--ink-meta);
  padding: 2px 8px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--paper-warm);
}

.channel-fit {
  margin-top: auto;
  padding-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-meta);
  border-top: 1px dashed var(--line);
}

.channel-exclude {
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink-meta);
}

.channel-device {
  margin-top: auto;
  padding-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-meta);
  border-top: 1px dashed var(--line);
}

/* 首页题材缩略图 */
.channel-thumb {
  display: flex;
  flex-direction: column;
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--paper-warm);
}

.channel-thumb img {
  width: 100%;
  height: 100%;
  min-height: 180px;
  max-height: 260px;
  object-fit: cover;
}

.channel-thumb figcaption {
  padding: 10px 14px 12px;
  margin-top: 0;
  background: var(--paper);
  border-top: 1px solid var(--line);
}

/* 专题片单预览 */
.feature-preview {
  background: var(--paper-warm);
  max-width: none;
  padding-left: 0;
  padding-right: 0;
}

.feature-preview > .section-head,
.feature-preview > .feature-list,
.feature-preview > .section-more {
  max-width: var(--shell);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

.feature-preview > .feature-list {
  padding-left: 24px;
  padding-right: 24px;
}

.feature-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.feature-item {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  gap: 22px;
  padding: 20px 0;
  border-top: 1px solid var(--line);
  border-left: 3px solid transparent;
  padding-left: 16px;
  transition: transform 160ms ease, border-color 160ms ease;
}

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

.feature-item:hover {
  transform: translateY(-2px);
  border-left-color: var(--accent);
}

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

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

.feature-body {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.feature-tag {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--accent);
}

.feature-body h3 {
  font-size: 19px;
  line-height: 1.5;
}

.feature-meta {
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-meta);
}

.feature-meta .mono {
  color: var(--ink);
}

.feature-reason {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* 画质摘要 */
.quality-summary {
  border-bottom: 1px solid var(--line);
}

.quality-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(240px, 1fr);
  gap: 36px;
  align-items: start;
}

.quality-text {
  min-width: 0;
}

.quality-text h2 {
  margin-bottom: 8px;
}

.quality-table {
  margin-top: 18px;
}

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

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

/* 观看流程四步 */
.step-list {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0;
  border-top: 1px solid var(--line);
}

.step-item {
  display: flex;
  gap: 12px;
  padding: 20px 18px 20px 0;
  border-left: 1px solid var(--line);
  padding-left: 18px;
  min-width: 0;
}

.step-item:first-child {
  border-left: 0;
  padding-left: 0;
}

.step-num {
  flex: 0 0 auto;
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--accent);
  line-height: 1.7;
}

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

.step-action {
  font-size: 15px;
  font-weight: 700;
  line-height: 1.7;
  color: var(--ink);
}

.step-expect {
  margin-top: 6px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink-soft);
}

/* 首页答疑中心 */
.faq-shell {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 32px;
  align-items: start;
}

.topic-index {
  min-width: 0;
  background: var(--paper-warm);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 16px;
  position: sticky;
  top: calc(var(--header-h) + 20px);
}

.topic-index-title {
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 10px;
  letter-spacing: 0.02em;
}

.topic-list li {
  border-top: 1px solid var(--line);
}

.topic-list li:first-child {
  border-top: 0;
}

.topic-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 9px 0;
  font-size: 14px;
  line-height: 1.6;
  color: var(--ink-soft);
}

.topic-link.is-current {
  color: var(--ink);
  font-weight: 700;
  border-bottom: 1px solid var(--accent);
}

.topic-link:hover {
  color: var(--accent);
}

.topic-count {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink-meta);
}

.faq-list {
  min-width: 0;
  border-top: 1px solid var(--line);
}

/* 规范与整理批次摘要 */
.standard-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 36px;
  align-items: start;
}

.standard-points,
.standard-batches {
  min-width: 0;
}

.standard-points h3,
.standard-batches h3 {
  font-size: 15px;
  margin-bottom: 12px;
  letter-spacing: 0.02em;
}

.point-list li {
  position: relative;
  padding: 10px 0 10px 16px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
  border-top: 1px solid var(--line);
}

.point-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 20px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}

.batch-list {
  border-top: 1px solid var(--line);
}

.batch-row {
  display: grid;
  grid-template-columns: 96px 96px minmax(0, 1fr);
  gap: 10px;
  padding: 10px 0;
  border-bottom: 1px solid var(--line);
  font-size: 14px;
  line-height: 1.7;
  align-items: baseline;
}

.batch-no,
.batch-id {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--ink);
}

.batch-type {
  font-size: 13px;
  color: var(--accent);
}

.batch-desc {
  font-size: 14px;
  color: var(--ink-soft);
  min-width: 0;
}

/* --------------------------------------------------------------------------
   pages · 频道索引
   -------------------------------------------------------------------------- */

.page-head {
  margin-bottom: 34px;
}

.page-head .page-lead {
  margin-top: 0;
}

.channel-groups {
  margin-bottom: 46px;
}

.group-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.channel-figure {
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--paper-warm);
}

.channel-figure img {
  width: 100%;
  aspect-ratio: 4 / 3;
  height: auto;
  object-fit: cover;
}

.channel-figure figcaption {
  margin-top: 0;
  padding: 10px 14px 12px;
  background: var(--paper);
  border-top: 1px solid var(--line);
}

.channel-table {
  margin-bottom: 46px;
}

.compare-table {
  margin-top: 4px;
}

.channel-pick-device {
  margin-bottom: 46px;
}

.device-columns {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.device-col {
  min-width: 0;
  padding: 18px 18px 20px;
  background: var(--paper-warm);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.device-col h3 {
  font-size: 16px;
  margin-bottom: 8px;
}

.device-col p {
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-soft);
  margin-bottom: 6px;
}

.device-col p:last-child {
  margin-bottom: 0;
}

.channel-pick {
  margin-bottom: 8px;
}

.pick-steps {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0;
  border-top: 1px solid var(--line);
}

.pick-step {
  min-width: 0;
  padding: 18px 18px 18px 0;
  border-left: 1px solid var(--line);
  padding-left: 18px;
}

.pick-step:first-child {
  border-left: 0;
  padding-left: 0;
}

.pick-step .step-num {
  display: block;
  margin-bottom: 6px;
}

.pick-step h3 {
  font-size: 16px;
  margin-bottom: 6px;
}

.pick-step p {
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* --------------------------------------------------------------------------
   pages · 专题片单
   -------------------------------------------------------------------------- */

.issue-note {
  margin-bottom: 40px;
}

.issue-note h2 {
  margin-bottom: 14px;
}

.issue-note-box {
  background: var(--paper-warm);
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 18px 20px;
}

.issue-note-box p {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
  margin-bottom: 8px;
}

.issue-note-box p:last-child {
  margin-bottom: 0;
}

.issue-note-box strong {
  color: var(--ink);
}

.layout-main > .feature-list {
  margin-bottom: 40px;
}

.layout-main > .feature-list > h2 {
  margin-bottom: 14px;
}

#feature-01,
#feature-02,
#feature-03,
#feature-04 {
  scroll-margin-top: calc(var(--header-h) + 16px);
}

.feature-anchors {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 12px;
  margin-top: 4px;
}

.feature-anchors li a {
  font-size: 13px;
  line-height: 1.6;
  color: var(--ink-meta);
  border-bottom: 1px dotted var(--line);
}

.feature-anchors li a:hover {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.field-note {
  margin-bottom: 40px;
}

.field-note h2 {
  margin-bottom: 10px;
}

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

.watch-order h2 {
  margin-bottom: 14px;
}

.watch-order-list {
  border-top: 1px solid var(--line);
}

.watch-order-list li {
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.watch-order-list li h3 {
  font-size: 16px;
  margin-bottom: 4px;
}

.watch-order-list li p {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* --------------------------------------------------------------------------
   pages · 画质与设备适配
   -------------------------------------------------------------------------- */

.page-title-block {
  margin-bottom: 34px;
}

.page-title-block .page-lead {
  margin-top: 0;
}

.report-toc {
  background: var(--paper-warm);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 16px;
}

.toc-title {
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 10px;
  letter-spacing: 0.02em;
}

.toc-list li {
  border-top: 1px solid var(--line);
}

.toc-list li:first-child {
  border-top: 0;
}

.toc-link {
  display: block;
  padding: 8px 0;
  font-size: 14px;
  line-height: 1.6;
  color: var(--ink-soft);
  border-left: 2px solid transparent;
  padding-left: 10px;
  margin-left: -10px;
}

.toc-link.is-current {
  color: var(--ink);
  font-weight: 700;
  border-left-color: var(--accent);
}

.toc-link:hover {
  color: var(--accent);
}

.report-body {
  max-width: 820px;
}

.report-body section {
  margin-bottom: 42px;
  scroll-margin-top: calc(var(--header-h) + 16px);
}

.report-body section:last-child {
  margin-bottom: 0;
}

.report-body h2 {
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line);
}

.report-body > section > p {
  font-size: 16px;
  line-height: 1.8;
  color: var(--ink-soft);
  margin-bottom: 12px;
}

.summary-box {
  background: var(--paper-warm);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 20px;
}

.summary-list li {
  position: relative;
  padding: 8px 0 8px 18px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
  border-top: 1px solid var(--line);
}

.summary-list li:first-child {
  border-top: 0;
  padding-top: 0;
}

.summary-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 18px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}

.summary-list li strong {
  color: var(--ink);
}

.data-table {
  margin: 14px 0 0;
}

.bitrate-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(220px, 1fr);
  gap: 24px;
  align-items: start;
  margin-top: 14px;
}

.bitrate-grid .data-table {
  margin-top: 0;
}

.bitrate-note {
  min-width: 0;
  background: var(--paper-warm);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px 18px;
}

.bitrate-note h3 {
  font-size: 15px;
  margin-bottom: 8px;
}

.bitrate-note p {
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-soft);
  margin-bottom: 8px;
}

.bitrate-note p:last-child {
  margin-bottom: 0;
}

.device-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(220px, 1fr);
  gap: 28px;
  align-items: start;
  margin-top: 6px;
}

.device-text {
  min-width: 0;
}

.device-text h3 {
  font-size: 16px;
  margin-bottom: 4px;
}

.device-text p {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
  margin-bottom: 14px;
}

.device-text p:last-child {
  margin-bottom: 0;
}

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

.device-figure img {
  width: 100%;
  aspect-ratio: 4 / 3;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line);
}

.setting-list {
  border-top: 1px solid var(--line);
  margin-top: 6px;
}

.setting-item {
  display: grid;
  grid-template-columns: 130px 130px minmax(0, 1fr);
  gap: 10px 18px;
  padding: 12px 0;
  border-bottom: 1px solid var(--line);
  font-size: 15px;
  line-height: 1.7;
  align-items: baseline;
}

.setting-name {
  font-weight: 700;
  color: var(--ink);
}

.setting-value {
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--accent);
}

.setting-effect {
  font-size: 14px;
  color: var(--ink-soft);
  min-width: 0;
}

.display-figure {
  margin-top: 20px;
  max-width: 560px;
}

.display-figure img {
  width: 100%;
  aspect-ratio: 16 / 9;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line);
}

.source-note {
  background: var(--paper-warm);
  border: 1px solid var(--line);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 14px 18px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.source-note a {
  color: var(--ink);
  border-bottom: 1px solid var(--accent);
}

.source-note a:hover {
  color: var(--accent);
}

.next-step {
  max-width: var(--shell);
  margin: 56px auto 0;
  padding: 28px 24px;
  background: var(--paper-warm);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.next-step h2 {
  font-size: 20px;
  margin-bottom: 8px;
}

.next-step p {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* --------------------------------------------------------------------------
   pages · 观看流程
   -------------------------------------------------------------------------- */

.page-intro {
  margin-bottom: 34px;
}

.checklist {
  margin-bottom: 42px;
}

.checklist h2 {
  margin-bottom: 10px;
}

.checklist-list {
  border-top: 1px solid var(--line);
  margin-top: 14px;
}

.checklist-item {
  display: grid;
  grid-template-columns: 160px minmax(0, 1fr);
  gap: 8px 20px;
  padding: 12px 0;
  border-bottom: 1px solid var(--line);
  align-items: baseline;
}

.checklist-name {
  position: relative;
  padding-left: 22px;
  font-size: 15px;
  font-weight: 700;
  color: var(--ink);
}

.checklist-name::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  width: 12px;
  height: 12px;
  border: 1px solid var(--ink-meta);
  border-radius: 2px;
  background: var(--paper);
}

.checklist-note {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
  min-width: 0;
}

.steps {
  margin-bottom: 42px;
}

.steps h2 {
  margin-bottom: 10px;
}

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

.step-item {
  min-width: 0;
}

.steps .step-item {
  display: block;
  padding: 20px 0;
  border-top: 1px solid var(--line);
  border-left: 0;
}

.steps .step-item:last-child {
  border-bottom: 1px solid var(--line);
}

.step-head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 12px;
}

.step-head .step-num {
  color: var(--accent);
}

.step-head h3 {
  font-size: 18px;
}

.step-action,
.step-expect,
.step-error {
  padding: 10px 14px;
  border-radius: var(--radius);
  margin-bottom: 8px;
}

.step-action {
  background: var(--paper);
  border: 1px solid var(--line);
}

.step-expect {
  background: var(--paper-warm);
  border: 1px solid var(--line);
}

.step-error {
  background: var(--paper);
  border: 1px dashed var(--line);
}

.step-label {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--ink-meta);
  margin-bottom: 2px;
}

.steps .step-action > p:last-child,
.steps .step-expect > p:last-child,
.steps .step-error > p:last-child {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.steps .step-action > p:last-child a,
.steps .step-error > p:last-child a {
  color: var(--ink);
  border-bottom: 1px solid var(--accent);
}

.steps .step-action > p:last-child a:hover,
.steps .step-error > p:last-child a:hover {
  color: var(--accent);
}

.step-figure {
  margin: 0 0 8px;
  max-width: 520px;
}

.step-figure img {
  width: 100%;
  aspect-ratio: 16 / 9;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line);
}

.troubleshoot {
  margin-bottom: 42px;
}

.troubleshoot h2 {
  margin-bottom: 10px;
}

.troubleshoot .data-table {
  margin-top: 16px;
}

.after {
  margin-bottom: 8px;
}

.after h2 {
  margin-bottom: 10px;
}

.after p {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
  margin-bottom: 8px;
}

/* --------------------------------------------------------------------------
   pages · 观看规范
   -------------------------------------------------------------------------- */

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

.page-body > .page-title {
  padding-bottom: 22px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 34px;
}

.standard-section {
  margin-bottom: 42px;
  padding-bottom: 42px;
  border-bottom: 1px solid var(--line);
  scroll-margin-top: calc(var(--header-h) + 16px);
}

.standard-section:last-of-type {
  border-bottom: 0;
  padding-bottom: 0;
}

.standard-section h2 {
  margin-bottom: 12px;
}

.standard-section > p {
  font-size: 16px;
  line-height: 1.8;
  color: var(--ink-soft);
  margin-bottom: 12px;
}

.standard-section .compare-table {
  margin-top: 16px;
}

.feedback-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(220px, 1fr);
  gap: 28px;
  align-items: start;
  margin-top: 16px;
}

.feedback-steps {
  min-width: 0;
}

.feedback-steps ol {
  counter-reset: feedback-step;
  border-top: 1px solid var(--line);
}

.feedback-steps ol li {
  counter-increment: feedback-step;
  position: relative;
  padding: 12px 0 12px 40px;
  border-bottom: 1px solid var(--line);
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.feedback-steps ol li::before {
  content: counter(feedback-step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 12px;
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--accent);
}

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

.feedback-figure img {
  width: 100%;
  aspect-ratio: 4 / 3;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line);
}

.standard-section > p > a {
  color: var(--ink);
  border-bottom: 1px solid var(--accent);
}

.standard-section > p > a:hover {
  color: var(--accent);
}

.page-next {
  margin-top: 8px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.page-next a {
  color: var(--ink);
  border-bottom: 1px solid var(--accent);
  margin-right: 16px;
}

.page-next a:hover {
  color: var(--accent);
}

/* --------------------------------------------------------------------------
   pages · 观看答疑
   -------------------------------------------------------------------------- */

.faq-center {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  gap: 36px;
  align-items: start;
  max-width: none;
  padding: 0;
  margin: 0 0 46px;
}

.faq-center .topic-index {
  padding: 18px 16px;
}

.faq-center .faq-list {
  border-top: 0;
}

.faq-group {
  margin-bottom: 34px;
  scroll-margin-top: calc(var(--header-h) + 16px);
}

.faq-group:last-child {
  margin-bottom: 0;
}

.faq-group-title {
  font-size: 17px;
  margin-bottom: 10px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--ink);
}

.faq-group .faq-item:first-of-type {
  border-top: 1px solid var(--line);
}

.trouble-order {
  margin-bottom: 46px;
  padding-top: 34px;
  border-top: 1px solid var(--line);
}

.trouble-order h2 {
  margin-bottom: 10px;
}

.order-list {
  counter-reset: trouble-order;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0;
  margin-top: 18px;
  border-top: 1px solid var(--line);
}

.order-list li {
  counter-increment: trouble-order;
  min-width: 0;
  padding: 18px 18px 18px 0;
  border-left: 1px solid var(--line);
  padding-left: 18px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.order-list li:first-child {
  border-left: 0;
  padding-left: 0;
}

.order-num {
  display: block;
  margin-bottom: 6px;
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--accent);
}

.nature-note {
  padding: 32px 0 8px;
  border-top: 1px solid var(--line);
}

.nature-note h2 {
  margin-bottom: 14px;
}

.nature-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(220px, 1fr);
  gap: 28px;
  align-items: start;
}

.nature-text {
  min-width: 0;
}

.nature-text p {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
  margin-bottom: 12px;
}

.nature-text p:last-child {
  margin-bottom: 0;
}

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

.nature-figure img {
  width: 100%;
  aspect-ratio: 4 / 3;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line);
}

/* --------------------------------------------------------------------------
   pages · 404
   -------------------------------------------------------------------------- */

.error-main {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 24px 72px;
}

.error-block {
  max-width: 640px;
  padding: 72px 0 48px;
}

.error-code {
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--accent);
  margin-bottom: 10px;
}

.error-block h1 {
  margin-bottom: 14px;
}

.error-text {
  font-size: 16px;
  line-height: 1.8;
  color: var(--ink-soft);
  margin-bottom: 22px;
}

.error-links {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px 16px;
  margin-bottom: 26px;
}

.error-links li a {
  display: block;
  padding: 10px 14px;
  font-size: 15px;
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
}

.error-links li a:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.error-home {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 22px;
  font-size: 15px;
  font-weight: 700;
  color: #FFFFFF;
  background: var(--accent);
  border: 1px solid var(--accent);
  border-radius: var(--radius);
}

.error-home:hover {
  background: #C93A14;
  border-color: #C93A14;
  color: #FFFFFF;
}

/* --------------------------------------------------------------------------
   responsive
   -------------------------------------------------------------------------- */

@media (max-width: 1080px) {
  .footer-inner {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 28px 24px;
  }

  .footer-brand {
    grid-column: 1 / -1;
  }

  .footer-intro {
    max-width: 52ch;
  }

  .page-layout,
  .page-layout.layout-shell {
    grid-template-columns: minmax(0, 1fr) 260px;
    gap: 32px;
  }

  .sidebar-left {
    grid-template-columns: 220px minmax(0, 1fr);
  }

  .faq-center {
    grid-template-columns: 220px minmax(0, 1fr);
    gap: 28px;
  }

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

  .step-list .step-item:nth-child(odd) {
    border-left: 0;
    padding-left: 0;
  }

  .step-list .step-item:nth-child(n + 3) {
    border-top: 1px solid var(--line);
  }

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

  .order-list li:nth-child(odd) {
    border-left: 0;
    padding-left: 0;
  }

  .order-list li:nth-child(n + 3) {
    border-top: 1px solid var(--line);
  }
}

@media (max-width: 900px) {
  .main-nav.site-nav {
    display: none;
  }

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

  .header-inner {
    gap: 12px;
  }

  .notice-toggle {
    margin-left: 0;
  }
}

@media (max-width: 720px) {
  :root {
    --header-h: 58px;
  }

  body {
    font-size: 15.5px;
    line-height: 1.75;
  }

  h1,
  .page-title {
    font-size: 28px;
    line-height: 1.3;
  }

  h2 {
    font-size: 20px;
  }

  h3 {
    font-size: 17px;
  }

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

  .header-inner {
    padding: 0 16px;
    min-height: var(--header-h);
  }

  .brand {
    font-size: 17px;
  }

  .notice-toggle {
    min-height: 32px;
    padding: 0 10px;
    font-size: 12px;
  }

  .notice-toggle::after {
    content: "";
  }

  .notice-text {
    padding: 10px 0 10px 16px;
    font-size: 12.5px;
  }

  .notice-panel {
    padding: 12px 16px 14px;
  }

  .mobile-nav-list {
    padding: 6px 16px 12px;
  }

  .breadcrumb {
    padding: 14px 0 2px;
    font-size: 12.5px;
  }

  .page-header {
    padding: 8px 0 18px;
    margin-bottom: 24px;
  }

  .page-lead {
    margin-top: 10px;
    font-size: 15px;
  }

  .page-meta {
    font-size: 12.5px;
  }

  /* 焦点区转为图下卡片 */
  .focus-media img {
    height: 220px;
  }

  .focus-media::after {
    background: rgba(17, 18, 20, 0.72);
  }

  .focus-caption {
    position: static;
    padding: 20px 16px 24px;
    background: var(--ink);
    gap: 12px;
  }

  .focus-caption h1 {
    font-size: 26px;
    max-width: none;
  }

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

  .focus-actions {
    gap: 10px;
  }

  .btn {
    min-height: 44px;
    padding: 0 18px;
    font-size: 14px;
  }

  .quick-entry {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    padding: 0 16px;
  }

  .entry-cell {
    padding: 16px 14px;
    border-top: 1px solid var(--line);
  }

  .entry-cell:nth-child(odd) {
    border-left: 0;
  }

  .entry-cell:nth-child(-n + 2) {
    border-top: 0;
  }

  .channel-summary,
  .feature-preview,
  .quality-summary,
  .steps-preview,
  .faq-center,
  .standard-summary {
    padding: 36px 16px;
  }

  .feature-preview > .section-head,
  .feature-preview > .feature-list,
  .feature-preview > .section-more {
    padding-left: 16px;
    padding-right: 16px;
  }

  .section-head {
    margin-bottom: 18px;
  }

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

  .channel-thumb img {
    min-height: 160px;
    max-height: 220px;
  }

  .feature-item {
    grid-template-columns: minmax(0, 1fr);
    gap: 12px;
    padding: 18px 0 18px 12px;
  }

  .feature-media img {
    aspect-ratio: 16 / 9;
  }

  .quality-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 22px;
  }

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

  .step-list .step-item {
    border-left: 0;
    padding-left: 0;
    padding: 14px 0;
    border-top: 1px solid var(--line);
  }

  .step-list .step-item:first-child {
    border-top: 0;
  }

  /* 首页答疑：目录转横滑标签 */
  .faq-shell {
    grid-template-columns: minmax(0, 1fr);
    gap: 18px;
  }

  .faq-shell .topic-index {
    position: static;
    padding: 12px;
  }

  .faq-shell .topic-list {
    display: flex;
    gap: 8px;
    overflow-x: auto;
    padding-bottom: 4px;
    -webkit-overflow-scrolling: touch;
  }

  .faq-shell .topic-list li {
    flex: 0 0 auto;
    border-top: 0;
  }

  .faq-shell .topic-link {
    padding: 8px 12px;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: var(--paper);
    white-space: nowrap;
  }

  .faq-shell .topic-link.is-current {
    border-color: var(--accent);
    color: var(--accent);
  }

  .standard-inner {
    grid-template-columns: minmax(0, 1fr);
    gap: 26px;
  }

  .batch-row {
    grid-template-columns: 80px minmax(0, 1fr);
    gap: 4px 12px;
  }

  .batch-desc {
    grid-column: 1 / -1;
  }

  /* 内页布局转单列，主内容在前 */
  .page-layout,
  .page-layout.layout-shell,
  .sidebar-left {
    grid-template-columns: minmax(0, 1fr);
    gap: 28px;
  }

  .layout-side,
  .related,
  .stuck-points,
  .sidebar-left .report-toc {
    position: static;
  }

  .page-layout .report-toc {
    order: 0;
  }

  .page-layout .report-body {
    order: 1;
  }

  /* 表格转卡片 */
  table.data-table,
  table.compare-table,
  table.quality-table {
    display: block;
    font-size: 14px;
  }

  table.data-table caption,
  table.compare-table caption,
  table.quality-table caption {
    display: block;
  }

  table.data-table thead,
  table.compare-table thead,
  table.quality-table thead {
    display: none;
  }

  table.data-table tbody,
  table.compare-table tbody,
  table.quality-table tbody {
    display: block;
  }

  table.data-table tr,
  table.compare-table tr,
  table.quality-table tr {
    display: block;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 12px 14px;
    margin-bottom: 10px;
    background: var(--paper);
  }

  table.data-table td,
  table.compare-table td,
  table.quality-table td {
    display: block;
    padding: 4px 0;
    border-bottom: 0;
    font-size: 14px;
    line-height: 1.75;
    color: var(--ink-soft);
  }

  table.data-table td:first-child,
  table.compare-table td:first-child,
  table.quality-table td:first-child {
    font-weight: 700;
    color: var(--ink);
    font-size: 15px;
    padding-bottom: 6px;
  }

  .device-columns,
  .pick-steps {
    grid-template-columns: minmax(0, 1fr);
    gap: 0;
  }

  .pick-step {
    border-left: 0;
    padding-left: 0;
    padding: 14px 0;
    border-top: 1px solid var(--line);
  }

  .pick-step:first-child {
    border-top: 0;
  }

  .bitrate-grid,
  .device-grid,
  .feedback-grid,
  .nature-body {
    grid-template-columns: minmax(0, 1fr);
    gap: 20px;
  }

  .setting-item {
    grid-template-columns: minmax(0, 1fr);
    gap: 2px;
    padding: 12px 0;
  }

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

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

  .checklist-name::before {
    top: 4px;
  }

  .faq-item summary {
    padding: 13px 30px 13px 12px;
    font-size: 15px;
  }

  .faq-item > p,
  .faq-answer {
    padding: 0 30px 12px 12px;
    font-size: 14.5px;
  }

  .faq-center {
    grid-template-columns: minmax(0, 1fr);
    gap: 20px;
    margin-bottom: 36px;
  }

  .faq-center .topic-index {
    position: static;
    padding: 12px;
  }

  .faq-center .topic-list {
    display: flex;
    gap: 8px;
    overflow-x: auto;
    padding-bottom: 4px;
    -webkit-overflow-scrolling: touch;
  }

  .faq-center .topic-list li {
    flex: 0 0 auto;
    border-top: 0;
  }

  .faq-center .topic-link {
    padding: 8px 12px;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: var(--paper);
    white-space: nowrap;
    gap: 6px;
  }

  .faq-center .topic-link.is-current {
    border-color: var(--accent);
    color: var(--accent);
  }

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

  .order-list li {
    border-left: 0;
    padding-left: 0;
    padding: 12px 0;
    border-top: 1px solid var(--line);
  }

  .order-list li:first-child {
    border-top: 0;
  }

  .trouble-order {
    padding-top: 26px;
    margin-bottom: 36px;
  }

  .next-step {
    margin-top: 36px;
    padding: 22px 16px;
  }

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

  .error-block {
    padding: 44px 0 32px;
  }

  .error-links {
    grid-template-columns: minmax(0, 1fr);
  }

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

  .footer-brand {
    grid-column: auto;
  }

  .footer-bottom p {
    padding: 14px 16px 22px;
  }

  .footer-col ul li a {
    padding: 8px 0;
    min-height: 40px;
  }

  .display-figure,
  .step-figure {
    max-width: none;
  }
}

@media (max-width: 420px) {
  .focus-caption h1 {
    font-size: 24px;
  }

  .quick-entry {
    grid-template-columns: minmax(0, 1fr);
  }

  .entry-cell {
    border-left: 0;
    border-top: 1px solid var(--line);
  }

  .entry-cell:first-child {
    border-top: 0;
  }

  .notice-toggle {
    padding: 0 8px;
  }
}

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

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

  .channel-card:hover,
  .feature-item:hover {
    transform: none;
  }
}