/* ==========================================================================
   YY影院 · 全站样式表
   分组：base / layout / components / pages / responsive
   ========================================================================== */

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

:root {
  --color-page: #f5f6f8;
  --color-surface: #ffffff;
  --color-text: #1f2933;
  --color-text-muted: #5b6672;
  --color-accent: #2f6fed;
  --color-border: #e3e8ef;
  --color-success: #0f7b6c;
  --color-warn: #b45309;

  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;

  --container-max: 1120px;
  --read-max: 760px;

  --gap-xs: 8px;
  --gap-sm: 12px;
  --gap-md: 20px;
  --gap-lg: 32px;
  --gap-xl: 48px;

  --header-h: 64px;

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;

  --shadow-card: 0 1px 2px rgba(31, 41, 51, 0.04);
}

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

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

body {
  margin: 0;
  background-color: var(--color-page);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  font-variant-numeric: tabular-nums;
}

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

h1 {
  font-size: 30px;
}

h2 {
  font-size: 22px;
}

h3 {
  font-size: 18px;
}

p {
  margin: 0 0 var(--gap-sm);
}

p:last-child {
  margin-bottom: 0;
}

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

dl,
dd,
dt,
figure,
figcaption {
  margin: 0;
}

a {
  color: var(--color-accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

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

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

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

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

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 60;
  padding: 10px 16px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-size: 14px;
}

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

/* --------------------------------------------------------------------------
   layout · 页头 / 导航 / 主容器 / 页脚骨架
   -------------------------------------------------------------------------- */

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

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

.brand {
  display: flex;
  flex-direction: column;
  justify-content: center;
  color: var(--color-text);
  text-decoration: none;
  line-height: 1.25;
}

.brand:hover {
  text-decoration: none;
}

.brand-name {
  font-size: 19px;
  font-weight: 700;
}

.brand-slogan {
  font-size: 12px;
  color: var(--color-text-muted);
}

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

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

.nav-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 12px;
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  font-size: 15px;
  text-decoration: none;
}

.nav-link:hover {
  background-color: var(--color-page);
  color: var(--color-text);
  text-decoration: none;
}

.nav-link.is-current {
  color: var(--color-text);
  font-weight: 600;
  box-shadow: inset 0 -2px 0 var(--color-accent);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  width: 44px;
  height: 44px;
  padding: 0 10px;
  background-color: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

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

.site-main {
  display: block;
  width: 100%;
}

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

.inner-main {
  padding-top: var(--gap-md);
}

/* --------------------------------------------------------------------------
   components · 通用区块、标题、按钮、标签、链接
   -------------------------------------------------------------------------- */

.section {
  margin-top: var(--gap-xl);
}

.section-head {
  margin-bottom: var(--gap-md);
}

.section-title {
  font-size: 22px;
}

.section-desc {
  margin-top: var(--gap-xs);
  max-width: var(--read-max);
  color: var(--color-text-muted);
  font-size: 15px;
}

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

.section-foot {
  margin-top: var(--gap-md);
  font-size: 15px;
}

.section-lead {
  margin-top: var(--gap-xs);
  margin-bottom: var(--gap-md);
  max-width: var(--read-max);
  color: var(--color-text-muted);
  font-size: 15px;
}

.text-link {
  color: var(--color-accent);
  font-size: 15px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  border-radius: var(--radius-md);
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
}

.btn:hover {
  text-decoration: none;
}

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

.btn-primary:hover {
  background-color: #2560d8;
  border-color: #2560d8;
}

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

.btn-ghost:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.status-tag {
  display: inline-block;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 600;
  line-height: 1.6;
  white-space: nowrap;
}

.status-new {
  background-color: rgba(15, 123, 108, 0.1);
  color: var(--color-success);
}

.status-adjust {
  background-color: rgba(180, 83, 9, 0.1);
  color: var(--color-warn);
}

.status-archive {
  background-color: rgba(91, 102, 114, 0.12);
  color: var(--color-text-muted);
}

/* 图片容器统一约束 */
.channel-figure,
.channel-media,
.topic-media,
.guide-media,
.updates-media {
  overflow: hidden;
  border-radius: var(--radius-md);
  background-color: var(--color-page);
}

.channel-figure img,
.channel-media img,
.topic-media img,
.guide-media img,
.updates-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* 表格通用 */
.table-scroll,
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-surface);
}

.compare-table th,
.compare-table td,
.data-table th,
.data-table td,
.quality-table th,
.quality-table td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--color-border);
  text-align: left;
  font-size: 15px;
  vertical-align: top;
}

.compare-table thead th,
.data-table thead th,
.quality-table thead th {
  background-color: var(--color-page);
  font-size: 14px;
  font-weight: 600;
  color: var(--color-text-muted);
  white-space: nowrap;
}

.compare-table tbody th,
.data-table tbody th {
  font-weight: 600;
  color: var(--color-text);
}

.compare-table tbody tr:last-child th,
.compare-table tbody tr:last-child td,
.data-table tbody tr:last-child td,
.quality-table tbody tr:last-child td {
  border-bottom: none;
}

.compare-caption,
.table-caption {
  padding: 12px 16px;
  text-align: left;
  font-size: 14px;
  color: var(--color-text-muted);
  caption-side: top;
}

/* 检查点清单（首页 / 观看指引共用结构，作用域分开） */
.checkpoint-item {
  display: flex;
  gap: var(--gap-sm);
  padding: 16px 0;
  border-bottom: 1px solid var(--color-border);
}

.checkpoint-item:last-child {
  border-bottom: none;
}

.checkpoint-index {
  flex: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background-color: var(--color-page);
  border: 1px solid var(--color-border);
  font-size: 13px;
  font-weight: 600;
  color: var(--color-text-muted);
}

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

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

.hero-section {
  margin-top: var(--gap-lg);
}

.hero-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: var(--gap-lg);
  align-items: start;
}

.hero-eyebrow {
  margin-bottom: var(--gap-xs);
  font-size: 13px;
  font-weight: 600;
  color: var(--color-accent);
}

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

.hero-lead {
  margin-top: var(--gap-sm);
  max-width: 32em;
  color: var(--color-text-muted);
  font-size: 16px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--gap-sm);
  margin-top: var(--gap-md);
}

.hero-entry-list {
  margin-top: var(--gap-md);
  display: grid;
  gap: var(--gap-xs);
}

.hero-entry-item {
  display: flex;
}

.hero-entry-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  width: 100%;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background-color: var(--color-surface);
  color: var(--color-text);
  font-size: 15px;
  text-decoration: none;
}

.hero-entry-link:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  text-decoration: none;
}

.hero-visual {
  display: grid;
  gap: var(--gap-md);
}

.hero-figure {
  border-radius: var(--radius-lg);
  overflow: hidden;
  background-color: var(--color-page);
}

.hero-figure img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.hero-figure-caption {
  padding: 10px 14px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-top: none;
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
  font-size: 14px;
  color: var(--color-text-muted);
}

.hero-topic-brief {
  padding: 18px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
}

.hero-brief-title {
  font-size: 18px;
}

.hero-brief-text {
  margin-top: var(--gap-xs);
  color: var(--color-text-muted);
  font-size: 15px;
}

.hero-topic-brief .text-link {
  display: inline-block;
  margin-top: var(--gap-xs);
}

.channel-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--gap-md);
}

.channel-card {
  display: flex;
  flex-direction: column;
  padding: 16px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
}

.channel-card:hover {
  border-color: var(--color-accent);
}

.channel-figure {
  margin-bottom: var(--gap-sm);
}

.channel-figure img {
  aspect-ratio: 16 / 9;
}

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

.channel-fields {
  margin-top: var(--gap-xs);
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 4px 10px;
  font-size: 14px;
}

.channel-fields .field-label {
  color: var(--color-text-muted);
  white-space: nowrap;
}

.channel-fields .field-value {
  color: var(--color-text);
}

.topic-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--gap-md);
}

.topic-card {
  display: flex;
  flex-direction: column;
  padding: 18px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
}

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

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

.topic-scope {
  margin-top: var(--gap-xs);
  color: var(--color-text-muted);
  font-size: 15px;
}

.topic-count {
  margin-top: var(--gap-xs);
  font-size: 14px;
  color: var(--color-text-muted);
}

.topic-card .text-link {
  margin-top: auto;
  padding-top: var(--gap-sm);
}

.update-timeline {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-surface);
  padding: 4px 18px;
}

.update-item {
  display: grid;
  grid-template-columns: 96px auto minmax(0, 1fr);
  align-items: baseline;
  gap: var(--gap-sm);
  padding: 14px 0;
  border-bottom: 1px solid var(--color-border);
}

.update-item:last-child {
  border-bottom: none;
}

.update-date {
  font-size: 14px;
  color: var(--color-text-muted);
}

.update-summary {
  font-size: 15px;
  color: var(--color-text);
}

.prepare-overview .checkpoint-list {
  padding: 4px 18px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-surface);
}

.prepare-overview .checkpoint-title {
  font-size: 16px;
}

.prepare-overview .checkpoint-text {
  margin-top: 4px;
  color: var(--color-text-muted);
  font-size: 15px;
}

.boundary-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
  gap: var(--gap-lg);
  padding: 20px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.boundary-text p {
  color: var(--color-text-muted);
  font-size: 15px;
}

.boundary-links-title {
  font-size: 16px;
}

.boundary-list {
  margin-top: var(--gap-xs);
  display: grid;
  gap: var(--gap-xs);
}

/* --------------------------------------------------------------------------
   pages · 内页外壳（面包屑 / 页面标题区）
   -------------------------------------------------------------------------- */

.breadcrumb {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  padding: 4px 0;
  font-size: 14px;
  color: var(--color-text-muted);
}

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

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

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

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

.page-header {
  margin-top: var(--gap-md);
  padding-bottom: var(--gap-md);
  border-bottom: 1px solid var(--color-border);
}

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

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

/* --------------------------------------------------------------------------
   pages · 频道分类（channels）
   -------------------------------------------------------------------------- */

.channel-overview {
  margin-top: var(--gap-lg);
}

.channel-overview .channel-card {
  gap: 0;
}

.channel-overview .channel-media {
  margin-bottom: var(--gap-sm);
}

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

.channel-field {
  margin-top: 4px;
  font-size: 14px;
  color: var(--color-text);
}

.channel-field .field-label {
  display: inline-block;
  min-width: 4.5em;
  color: var(--color-text-muted);
}

.channel-compare {
  margin-top: var(--gap-xl);
}

.field-legend {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 6px 12px;
  margin-bottom: var(--gap-md);
  max-width: var(--read-max);
  font-size: 14px;
}

.field-legend-term {
  color: var(--color-text);
  font-weight: 600;
  white-space: nowrap;
}

.field-legend-desc {
  color: var(--color-text-muted);
}

.channel-samples {
  margin-top: var(--gap-xl);
}

.sample-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--gap-sm) var(--gap-lg);
}

.sample-item {
  padding: 14px 0;
  border-bottom: 1px solid var(--color-border);
}

.sample-name {
  font-size: 16px;
}

.sample-desc {
  margin-top: 4px;
  color: var(--color-text-muted);
  font-size: 15px;
}

.channel-advice {
  margin-top: var(--gap-xl);
}

.advice-list {
  display: grid;
  gap: var(--gap-md);
}

.advice-item {
  padding: 16px 18px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-accent);
  border-radius: var(--radius-md);
}

.advice-title {
  font-size: 16px;
}

.advice-desc {
  margin-top: 4px;
  color: var(--color-text-muted);
  font-size: 15px;
}

/* --------------------------------------------------------------------------
   pages · 专题片单（topics）
   -------------------------------------------------------------------------- */

.topics-list-section {
  margin-top: var(--gap-lg);
}

.topics-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--gap-md);
}

.topics-grid .topic-card {
  padding: 0;
  overflow: hidden;
}

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

.topic-body {
  display: flex;
  flex-direction: column;
  flex: 1;
  padding: 16px;
}

.topic-title {
  font-size: 17px;
}

.link-more {
  display: inline-block;
  margin-top: auto;
  padding-top: var(--gap-sm);
  font-size: 15px;
  color: var(--color-accent);
}

.scope-list {
  display: grid;
  gap: var(--gap-md);
}

.scope-item {
  padding: 16px 18px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

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

.scope-text {
  margin-top: 6px;
  color: var(--color-text-muted);
  font-size: 15px;
}

.scope-boundary {
  margin-top: var(--gap-xs);
  padding-top: var(--gap-xs);
  border-top: 1px dashed var(--color-border);
  font-size: 14px;
  color: var(--color-warn);
}

.topics-advice-section .advice-list {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.topics-advice-section .advice-item {
  display: flex;
  flex-direction: column;
  padding: 16px;
}

.advice-text {
  margin-top: 6px;
  color: var(--color-text-muted);
  font-size: 15px;
}

.topics-advice-section .link-more {
  margin-top: auto;
}

/* --------------------------------------------------------------------------
   pages · 观看指引（guide）
   -------------------------------------------------------------------------- */

.page-layout {
  display: grid;
  gap: var(--gap-xl);
  margin-top: var(--gap-lg);
}

.guide-checkpoints .checkpoint-list {
  padding: 4px 18px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-surface);
}

.guide-checkpoints .checkpoint-name {
  font-size: 16px;
}

.guide-checkpoints .checkpoint-text {
  margin-top: 4px;
  color: var(--color-text-muted);
  font-size: 15px;
}

.guide-quality .guide-media {
  margin-bottom: var(--gap-md);
}

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

.guide-media-caption {
  padding: 10px 14px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-top: none;
  font-size: 14px;
  color: var(--color-text-muted);
}

.guide-note {
  margin-top: var(--gap-sm);
  font-size: 15px;
  color: var(--color-text-muted);
}

.faq-list {
  display: grid;
  gap: var(--gap-sm);
}

.faq-item {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 0 18px;
}

.faq-question {
  display: flex;
  align-items: center;
  min-height: 48px;
  padding: 12px 0;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}

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

.faq-question::after {
  content: "+";
  margin-left: auto;
  padding-left: var(--gap-sm);
  color: var(--color-text-muted);
  font-weight: 400;
}

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

.faq-answer {
  padding-bottom: 14px;
  border-top: 1px solid var(--color-border);
  padding-top: 12px;
  color: var(--color-text-muted);
  font-size: 15px;
}

.guide-boundary .boundary-body {
  padding: 18px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.guide-boundary .boundary-text {
  color: var(--color-text-muted);
  font-size: 15px;
}

/* --------------------------------------------------------------------------
   pages · 最近更新（updates）
   -------------------------------------------------------------------------- */

.updates-timeline,
.change-types,
.summary-links,
.archive-entry {
  margin-top: var(--gap-xl);
}

.updates-timeline {
  margin-top: var(--gap-lg);
}

.updates-media {
  margin-bottom: var(--gap-md);
}

.updates-media img {
  aspect-ratio: 16 / 6;
}

.updates-media-caption {
  padding: 10px 14px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-top: none;
  font-size: 14px;
  color: var(--color-text-muted);
}

.updates-month {
  margin-top: var(--gap-md);
  padding: 4px 18px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.updates-month-title {
  padding: 12px 0 8px;
  font-size: 16px;
  color: var(--color-text-muted);
}

.updates-row {
  display: grid;
  grid-template-columns: 110px auto minmax(0, 1fr);
  align-items: baseline;
  gap: var(--gap-sm);
  padding: 14px 0;
  border-top: 1px solid var(--color-border);
}

.updates-date {
  font-size: 14px;
  color: var(--color-text-muted);
}

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

.updates-summary {
  margin-top: 4px;
  color: var(--color-text-muted);
  font-size: 14px;
}

.change-type-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--gap-md);
}

.change-type-item {
  padding: 16px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.change-type-name {
  font-size: 16px;
}

.change-type-desc {
  margin-top: 6px;
  color: var(--color-text-muted);
  font-size: 15px;
}

.summary-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--gap-sm) var(--gap-lg);
}

.summary-item {
  padding: 14px 0;
  border-bottom: 1px solid var(--color-border);
}

.summary-name {
  font-size: 16px;
}

.summary-desc {
  margin-top: 4px;
  color: var(--color-text-muted);
  font-size: 15px;
}

.summary-link {
  margin-top: 6px;
  font-size: 14px;
}

.archive-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--gap-md);
}

.archive-item {
  padding: 16px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.archive-item a {
  font-weight: 600;
}

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

.archive-note {
  margin-top: var(--gap-md);
  font-size: 15px;
  color: var(--color-text-muted);
}

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

.error-main {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: var(--gap-xl) 24px;
}

.error-block {
  max-width: var(--read-max);
}

.error-lead {
  margin-top: var(--gap-sm);
  color: var(--color-text-muted);
}

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

.error-home-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  margin-top: var(--gap-md);
  padding: 0 20px;
  background-color: var(--color-accent);
  border-radius: var(--radius-md);
  color: #ffffff;
  font-weight: 600;
}

.error-home-link:hover {
  background-color: #2560d8;
  text-decoration: none;
}

.error-routes {
  margin-top: var(--gap-xl);
}

.error-route-list {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--gap-md);
}

.error-route-item a {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0 16px;
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-size: 15px;
}

.error-route-item a:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  text-decoration: none;
}

/* --------------------------------------------------------------------------
   layout · 页脚
   -------------------------------------------------------------------------- */

.site-footer {
  margin-top: var(--gap-xl);
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border);
}

.footer-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: var(--gap-lg) 24px var(--gap-md);
}

.footer-groups {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--gap-md);
}

.footer-group-title {
  font-size: 15px;
  font-weight: 600;
}

.footer-list {
  margin-top: var(--gap-xs);
  display: grid;
  gap: 6px;
}

.footer-list a {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  color: var(--color-text-muted);
  font-size: 14px;
}

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

.footer-about {
  font-size: 14px;
  color: var(--color-text-muted);
}

.footer-bottom {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--gap-sm);
  margin-top: var(--gap-lg);
  padding-top: var(--gap-md);
  border-top: 1px solid var(--color-border);
}

.footer-note {
  margin: 0;
  max-width: 60em;
  font-size: 13px;
  color: var(--color-text-muted);
}

.footer-copyright {
  margin: 0;
  font-size: 13px;
  color: var(--color-text-muted);
}

.back-to-top {
  margin-left: auto;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background-color: var(--color-page);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  font-size: 18px;
  line-height: 1;
}

.back-to-top::before {
  content: "\2191";
}

.back-to-top:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

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

@media (max-width: 900px) {
  .header-inner {
    flex-wrap: wrap;
    padding: 0 16px;
  }

  .nav-toggle {
    display: flex;
  }

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

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    width: 100%;
    padding: 8px 0 12px;
    border-top: 1px solid var(--color-border);
  }

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

  .nav-link {
    width: 100%;
    padding: 0 8px;
    border-radius: var(--radius-sm);
  }

  .nav-link.is-current {
    box-shadow: inset 3px 0 0 var(--color-accent);
  }

  .home-main,
  .inner-main,
  .error-main {
    padding-left: 16px;
    padding-right: 16px;
  }

  .hero-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--gap-md);
  }

  .hero-visual {
    order: 2;
  }

  .channel-grid,
  .topics-advice-section .advice-list,
  .change-type-list,
  .archive-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .topic-grid,
  .topics-grid,
  .sample-list,
  .summary-list {
    grid-template-columns: minmax(0, 1fr);
  }

  .boundary-layout {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--gap-md);
  }

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

  .footer-groups {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--gap-lg) var(--gap-md);
  }
}

@media (max-width: 620px) {
  body {
    font-size: 15px;
  }

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

  .section-title,
  h2 {
    font-size: 20px;
  }

  h3 {
    font-size: 16px;
  }

  .home-main,
  .inner-main {
    padding-bottom: var(--gap-lg);
  }

  .section {
    margin-top: var(--gap-lg);
  }

  .channel-grid,
  .topics-advice-section .advice-list,
  .change-type-list,
  .archive-list,
  .error-route-list {
    grid-template-columns: minmax(0, 1fr);
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .hero-actions .btn {
    width: 100%;
  }

  .update-item,
  .updates-row {
    grid-template-columns: minmax(0, 1fr);
    gap: 6px;
  }

  .update-date,
  .updates-date {
    font-size: 13px;
  }

  .compare-table th,
  .compare-table td,
  .data-table th,
  .data-table td,
  .quality-table th,
  .quality-table td {
    padding: 10px 12px;
    font-size: 14px;
  }

  .field-legend {
    grid-template-columns: minmax(0, 1fr);
    gap: 2px;
  }

  .field-legend-desc {
    margin-bottom: 8px;
  }

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

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

  .footer-inner {
    padding: var(--gap-lg) 16px var(--gap-md);
  }

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

  .back-to-top {
    margin-left: 0;
  }
}