/* ==========================================================================
   四海影院 · 全站样式
   分组：base / layout / components / pages / responsive
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. base
   -------------------------------------------------------------------------- */

:root {
  --paper: #f6f2e9;
  --surface: #fffdf7;
  --ink: #16211f;
  --brand: #0f5a57;
  --brand-deep: #0a3f3d;
  --accent: #d16f45;
  --accent-deep: #b45a34;
  --mint: #b9c8c2;
  --muted: #6a746f;
  --line: #d9d1c3;
  --line-soft: #e7e0d3;
  --radius: 8px;
  --radius-sm: 6px;
  --shadow: 0 1px 2px rgba(22, 33, 31, 0.05), 0 6px 18px rgba(22, 33, 31, 0.05);
  --shadow-lift: 0 2px 4px rgba(22, 33, 31, 0.07), 0 12px 26px rgba(22, 33, 31, 0.09);
  --font-serif: "Songti SC", "SimSun", "Noto Serif SC", serif;
  --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --container: 1180px;
  --reading: 760px;
  --gutter: 24px;
}

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

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

body {
  margin: 0;
  background-color: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
}

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

p {
  margin: 0;
}

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

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

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

a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

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

figure {
  margin: 0;
}

button {
  font: inherit;
  color: inherit;
}

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

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

.header-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 12px var(--gutter);
  display: flex;
  align-items: center;
  gap: 20px;
}

.brand {
  display: inline-flex;
  flex-direction: column;
  gap: 2px;
  flex-shrink: 0;
  color: var(--ink);
}

.brand:hover {
  color: var(--brand);
}

.brand-mark {
  font-family: var(--font-serif);
  font-size: 21px;
  font-weight: 600;
  line-height: 1.2;
}

.brand-slogan {
  font-size: 12px;
  line-height: 1.4;
  color: var(--muted);
}

.site-nav {
  flex: 1 1 auto;
  min-width: 0;
}

.nav-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 2px;
}

.nav-link {
  display: inline-block;
  padding: 8px 11px;
  font-size: 15px;
  line-height: 1.5;
  color: var(--ink);
  border-bottom: 2px solid transparent;
  border-radius: 4px 4px 0 0;
}

.nav-link:hover {
  color: var(--brand);
  background-color: rgba(15, 90, 87, 0.06);
}

.nav-link.is-current {
  color: var(--brand);
  font-weight: 500;
  border-bottom-color: var(--brand);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.btn-command {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  padding: 8px 18px;
  font-size: 14px;
  font-weight: 500;
  color: #fffdf7;
  background-color: var(--accent);
  border-radius: var(--radius-sm);
  white-space: nowrap;
}

.btn-command:hover {
  color: #fffdf7;
  background-color: var(--accent-deep);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 0;
  background-color: transparent;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  cursor: pointer;
}

.nav-toggle-bar {
  display: block;
  width: 20px;
  height: 2px;
  margin: 0 auto;
  background-color: var(--ink);
  border-radius: 2px;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

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

.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.site-main {
  display: block;
}

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

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  padding: 18px 0 4px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

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

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

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

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

.page-header {
  padding: 6px 0 4px;
}

.page-title {
  font-size: clamp(28px, 3.4vw, 42px);
  font-weight: 600;
  line-height: 1.28;
  color: var(--ink);
  max-width: 900px;
}

/* 内页统一标题说明区 */
.page-title-block,
section.page-title {
  display: flex;
  flex-direction: column;
  gap: 10px;
  max-width: 900px;
  padding: 12px 0 26px;
  border-bottom: 1px solid var(--line-soft);
  margin-bottom: 34px;
}

.page-eyebrow {
  font-size: 13px;
  font-weight: 500;
  line-height: 1.6;
  color: var(--accent-deep);
}

.page-lead {
  font-size: 17px;
  line-height: 1.8;
  color: var(--ink);
  max-width: 760px;
}

.page-path,
.page-path-note {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  max-width: 760px;
}

.page-path a,
.page-path-note a {
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.page-path a:hover,
.page-path-note a:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

/* 通用区块标题 */
.section-head {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 26px;
}

.section-head h2,
.section-title {
  font-size: clamp(22px, 2.4vw, 28px);
  font-weight: 600;
  line-height: 1.35;
  color: var(--ink);
}

.section-title {
  margin-bottom: 14px;
}

.section-intro,
.section-note,
.section-desc {
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
  max-width: 760px;
}

.section-note,
.section-desc {
  margin-bottom: 22px;
}

.section-intro {
  margin-bottom: 4px;
}

/* 通用文字链接 */
.text-link {
  display: inline-block;
  font-size: 14px;
  font-weight: 500;
  line-height: 1.6;
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
  padding-bottom: 1px;
}

.text-link:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

/* 页脚 */
.site-footer {
  background-color: var(--brand-deep);
  color: #e8efec;
  margin-top: 40px;
}

.footer-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 48px var(--gutter) 26px;
}

.footer-primary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 16px;
  padding-bottom: 26px;
  border-bottom: 1px solid rgba(232, 239, 236, 0.18);
}

.footer-cta-text {
  font-family: var(--font-serif);
  font-size: 20px;
  line-height: 1.5;
  color: #f3f7f5;
}

.footer-cta-link {
  font-size: 15px;
  font-weight: 500;
  color: #f0c9b2;
  border-bottom: 1px solid rgba(240, 201, 178, 0.5);
  padding-bottom: 1px;
}

.footer-cta-link:hover {
  color: #ffffff;
  border-bottom-color: #ffffff;
}

.footer-columns {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 28px 32px;
  padding: 30px 0 26px;
}

.footer-col-title {
  font-family: var(--font-sans);
  font-size: 13px;
  font-weight: 500;
  line-height: 1.6;
  color: #a9c2bb;
  margin-bottom: 12px;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-links a {
  display: inline-block;
  font-size: 14px;
  line-height: 1.6;
  color: #e2ebe7;
  padding: 2px 0;
}

.footer-links a:hover {
  color: #f0c9b2;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 24px;
  padding-top: 20px;
  border-top: 1px solid rgba(232, 239, 236, 0.18);
  font-size: 13px;
  line-height: 1.7;
  color: #a9c2bb;
}

.footer-about {
  max-width: 620px;
}

.footer-copy {
  color: #8fa8a2;
}

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

/* 按钮 */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 10px 24px;
  font-size: 15px;
  font-weight: 500;
  color: #fffdf7;
  background-color: var(--accent);
  border-radius: var(--radius-sm);
}

.btn-primary:hover {
  color: #fffdf7;
  background-color: var(--accent-deep);
}

.link-secondary {
  display: inline-flex;
  align-items: center;
  min-height: 46px;
  padding: 10px 4px;
  font-size: 15px;
  font-weight: 500;
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.link-secondary:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

/* 图片容器与图注 */
.hero-media,
.media,
.scope-figure,
.figure-media,
.info-figure,
.rule-figure,
.faq-figure,
.check-figure,
.guide-figure {
  margin: 0;
}

.hero-media img,
.media img,
.scope-media img,
.figure-media img,
.info-figure-media img,
.rule-figure-media img,
.faq-figure-media img {
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: var(--radius);
  background-color: var(--line-soft);
}

.hero-media figcaption,
.scope-caption,
.figure-caption,
.info-figure-caption,
.rule-figure-caption,
.faq-figure-caption,
.media figcaption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--muted);
}

/* 结论摘要列表 */
.summary-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.summary-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 16px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-left: 3px solid var(--brand);
  border-radius: var(--radius-sm);
}

.summary-text {
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink);
}

.summary-condition {
  font-size: 13px;
  line-height: 1.65;
  color: var(--muted);
}

.summary-link {
  align-self: flex-start;
  font-size: 14px;
  font-weight: 500;
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.summary-link:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

.summary-index {
  font-family: var(--font-serif);
  font-size: 13px;
  font-weight: 600;
  color: var(--accent-deep);
}

/* 步骤字段 */
.step-fields {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 24px;
  margin-top: 12px;
}

.step-field {
  padding: 12px 14px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-sm);
  min-width: 0;
}

.field-label {
  font-size: 12px;
  font-weight: 500;
  line-height: 1.6;
  color: var(--accent-deep);
  margin-bottom: 4px;
}

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

/* 折叠问答 */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

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

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 15px 18px;
  font-size: 15px;
  font-weight: 500;
  line-height: 1.6;
  color: var(--ink);
  cursor: pointer;
  list-style: none;
}

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

.faq-question::after {
  content: "+";
  flex-shrink: 0;
  font-family: var(--font-sans);
  font-size: 18px;
  font-weight: 400;
  line-height: 1;
  color: var(--brand);
}

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

.faq-question:hover {
  color: var(--brand);
}

.faq-answer {
  padding: 0 18px 16px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

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

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

.faq-link {
  display: inline-block;
  margin-top: 4px;
  font-size: 14px;
  font-weight: 500;
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.faq-link:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

/* 首页相关链接条 */
.related-links {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 18px;
  max-width: var(--container);
  margin: 36px auto 0;
  padding: 18px 0 0;
  border-top: 1px solid var(--line-soft);
}

.related-links-label {
  font-size: 13px;
  font-weight: 500;
  color: var(--muted);
}

.related-links-item {
  font-size: 14px;
  font-weight: 500;
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.related-links-item:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

/* --------------------------------------------------------------------------
   4. pages · 首页
   -------------------------------------------------------------------------- */

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

/* 首屏 */
.hero {
  display: grid;
  grid-template-columns: minmax(0, 56fr) minmax(0, 44fr);
  gap: 40px;
  align-items: center;
  padding: 40px 0 48px;
  border-bottom: 1px solid var(--line-soft);
}

.hero-copy {
  display: flex;
  flex-direction: column;
  gap: 16px;
  min-width: 0;
}

.hero-eyebrow {
  font-size: 13px;
  font-weight: 500;
  line-height: 1.6;
  color: var(--accent-deep);
}

.hero-copy h1 {
  font-size: clamp(30px, 4.2vw, 46px);
  line-height: 1.24;
  color: var(--ink);
}

.hero-lead {
  font-size: 17px;
  line-height: 1.8;
  color: var(--ink);
  max-width: 560px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 22px;
  margin-top: 6px;
}

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

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

/* 频道矩阵 */
.channel-matrix {
  padding: 48px 0 8px;
}

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

.channel-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.channel-card:hover {
  box-shadow: var(--shadow-lift);
  transform: translateY(-2px);
}

.channel-bar {
  display: block;
  width: 34px;
  height: 4px;
  border-radius: 2px;
  background-color: var(--brand);
}

.channel-card:nth-child(2) .channel-bar {
  background-color: var(--accent);
}

.channel-card:nth-child(3) .channel-bar {
  background-color: #5c8a7f;
}

.channel-card:nth-child(4) .channel-bar {
  background-color: #8a6f4b;
}

.channel-card:nth-child(5) .channel-bar {
  background-color: #4a6d8a;
}

.channel-card:nth-child(6) .channel-bar {
  background-color: #7a5a72;
}

.channel-name {
  font-size: 19px;
  line-height: 1.4;
}

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

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

.channel-link {
  margin-top: auto;
  align-self: flex-start;
  font-size: 14px;
  font-weight: 500;
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.channel-link:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

/* 专题片单摘要 */
.feature-collections {
  padding: 48px 0 8px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
}

.feature-card {
  display: flex;
  flex-direction: column;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.feature-card:hover {
  box-shadow: var(--shadow-lift);
  transform: translateY(-2px);
}

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

.feature-card .media img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  border-radius: 0;
}

.card-copy {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 18px 20px 20px;
  flex: 1 1 auto;
}

.feature-name {
  font-size: 19px;
  line-height: 1.4;
}

.feature-channel {
  font-size: 13px;
  line-height: 1.6;
  color: var(--accent-deep);
}

.feature-desc {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.feature-link {
  margin-top: auto;
  align-self: flex-start;
  padding-top: 4px;
  font-size: 14px;
  font-weight: 500;
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.feature-link:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

/* 内容组织纵线 */
.content-flow {
  padding: 48px 0 8px;
}

.flow-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.content-flow .step {
  padding: 20px 22px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
}

.content-flow .step-title {
  font-size: 17px;
  line-height: 1.5;
}

/* 入口核验摘要 */
.entry-check-teaser {
  padding: 48px 0 8px;
}

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

.check-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-top: 3px solid var(--accent);
  border-radius: var(--radius);
}

.check-name {
  font-size: 17px;
  line-height: 1.45;
}

.check-reason {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.check-link {
  margin-top: auto;
  align-self: flex-start;
  font-size: 14px;
  font-weight: 500;
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.check-link:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

/* 观看指南结论摘要（首页） */
.home-main .guide-summary {
  padding: 48px 0 8px;
}

.home-main .guide-summary .summary-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.home-main .guide-summary .summary-item {
  height: 100%;
}

/* 首页 FAQ */
.faq {
  padding: 48px 0 8px;
}

/* --------------------------------------------------------------------------
   4. pages · 内页通用正文列
   -------------------------------------------------------------------------- */

.inner-main > section,
.inner-main > figure,
.inner-main > div:not(.breadcrumb):not(.page-header):not(.guide-layout) {
  max-width: 900px;
}

.inner-main > section,
.inner-main > figure {
  margin-bottom: 38px;
}

.inner-main > section:last-of-type {
  margin-bottom: 12px;
}

/* 频道总览 */
.channel-scope .scope-figure {
  max-width: 900px;
}

.scope-media img {
  width: 100%;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line-soft);
}

.channel-conclusion .conclusion-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.channel-conclusion .conclusion-item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 14px;
  padding: 14px 16px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-left: 3px solid var(--brand);
  border-radius: var(--radius-sm);
}

.channel-conclusion .conclusion-text {
  flex: 1 1 320px;
  font-size: 15px;
  line-height: 1.75;
  min-width: 0;
}

/* 频道字段总表 */
.channel-table {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background-color: var(--surface);
}

.channel-row {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 2fr) minmax(0, 1.2fr) minmax(0, 1fr);
  gap: 0;
  border-top: 1px solid var(--line-soft);
}

.channel-row:first-child {
  border-top: 0;
}

.channel-row-head {
  background-color: rgba(15, 90, 87, 0.07);
}

.channel-cell {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 13px 16px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink);
  border-left: 1px solid var(--line-soft);
  min-width: 0;
}

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

.channel-row-head .channel-cell {
  font-size: 13px;
  font-weight: 500;
  color: var(--brand);
}

.cell-name {
  font-weight: 500;
}

.channel-table .channel-bar {
  width: 4px;
  height: 22px;
  flex-shrink: 0;
}

.channel-table .bar-1 {
  background-color: var(--brand);
}

.channel-table .bar-2 {
  background-color: var(--accent);
}

.channel-table .bar-3 {
  background-color: #5c8a7f;
}

.channel-table .bar-4 {
  background-color: #8a6f4b;
}

.channel-table .bar-5 {
  background-color: #4a6d8a;
}

.channel-table .bar-6 {
  background-color: #7a5a72;
}

.cell-scope,
.cell-topic {
  color: var(--muted);
}

/* 频道选择建议 */
.advice-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.advice-item {
  padding: 18px 20px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
}

.advice-title {
  font-size: 16px;
  line-height: 1.5;
  margin-bottom: 8px;
}

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

/* 频道到专题衔接 */
.bridge-columns {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px;
}

.bridge-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 22px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
}

.bridge-card-title {
  font-size: 18px;
  line-height: 1.45;
}

.bridge-card-text {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.bridge-card .text-link {
  margin-top: auto;
  align-self: flex-start;
}

/* 频道页相关页面 */
.related-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 24px;
}

.related-item {
  font-size: 14px;
}

/* 专题片单 */
.collection-intro {
  max-width: 900px;
}

.conclusion-bar {
  padding: 18px 20px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  margin-bottom: 18px;
}

.conclusion-bar .conclusion-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.conclusion-bar .conclusion-item {
  position: relative;
  padding-left: 18px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink);
}

.conclusion-bar .conclusion-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: var(--accent);
}

.intro-text {
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 760px;
}

.intro-text a {
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.intro-text a:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

.topic-list {
  max-width: 980px;
}

.topic-card {
  display: grid;
  grid-template-columns: minmax(0, 44fr) minmax(0, 56fr);
  gap: 26px;
  align-items: start;
  padding: 22px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  margin-bottom: 22px;
}

.topic-card:nth-child(even) {
  grid-template-columns: minmax(0, 56fr) minmax(0, 44fr);
}

.topic-card:nth-child(even) .media {
  order: 2;
}

.topic-card:nth-child(even) .topic-copy {
  order: 1;
}

.topic-card .media img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: var(--radius-sm);
}

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

.topic-name {
  font-size: 20px;
  line-height: 1.4;
}

.topic-channel {
  font-size: 13px;
  line-height: 1.6;
  color: var(--accent-deep);
}

.topic-channel a {
  color: var(--accent-deep);
  border-bottom: 1px solid rgba(209, 111, 69, 0.4);
}

.topic-channel a:hover {
  color: var(--brand);
  border-bottom-color: var(--brand);
}

.topic-desc {
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
}

.topic-entry-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-left: 0;
}

.topic-entry-list li {
  position: relative;
  padding-left: 14px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink);
}

.topic-entry-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background-color: var(--brand);
}

.topic-links {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 20px;
  margin-top: 4px;
}

.topic-links a {
  font-size: 14px;
  font-weight: 500;
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.topic-links a:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

/* 专题与频道关系 */
.relation-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin: 0;
  border-top: 1px solid var(--line-soft);
}

.relation-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 2.4fr);
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line-soft);
}

.relation-term {
  font-family: var(--font-serif);
  font-size: 16px;
  font-weight: 600;
  line-height: 1.6;
  color: var(--ink);
}

.relation-desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  min-width: 0;
}

/* 专题阅读顺序 */
.order-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.order-item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 14px;
  padding: 14px 16px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-sm);
}

.order-text {
  flex: 1 1 320px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink);
  min-width: 0;
}

.order-item a {
  font-size: 14px;
  font-weight: 500;
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.order-item a:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

/* 专题相关入口 */
.related-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px;
}

.related-col {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
}

.related-title {
  font-size: 17px;
  line-height: 1.45;
}

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

.related-col a {
  margin-top: auto;
  align-self: flex-start;
  font-size: 14px;
  font-weight: 500;
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.related-col a:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

/* 观看指南 */
.guide-layout {
  max-width: var(--reading);
  display: flex;
  flex-direction: column;
  gap: 38px;
}

.guide-layout > section {
  margin: 0;
}

.guide-layout .guide-summary .summary-list {
  margin-top: 12px;
}

.guide-figure .figure-media img {
  width: 100%;
  aspect-ratio: 16 / 8;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line-soft);
}

.guide-principle .step {
  padding: 18px 20px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  margin-top: 14px;
}

.guide-principle .step:first-of-type {
  margin-top: 0;
}

.guide-principle .step-title {
  font-size: 17px;
  line-height: 1.5;
}

.guide-principle .step-field-title {
  font-size: 12px;
  font-weight: 500;
  line-height: 1.6;
  color: var(--accent-deep);
  margin-bottom: 4px;
}

.guide-principle .step-field-text {
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink);
}

.guide-example .example-item {
  padding: 18px 20px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-left: 3px solid var(--brand);
  border-radius: var(--radius-sm);
  margin-top: 14px;
}

.guide-example .example-item:first-of-type {
  margin-top: 0;
}

.example-title {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: 16px;
  line-height: 1.5;
  margin-bottom: 8px;
}

.example-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  flex-shrink: 0;
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 500;
  color: var(--surface);
  background-color: var(--brand);
  border-radius: 50%;
}

.example-context {
  font-size: 14px;
  line-height: 1.78;
  color: var(--ink);
  margin-bottom: 6px;
}

.example-judge {
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
  margin-bottom: 6px;
}

.example-judge a {
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.example-judge a:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

.example-next {
  font-size: 14px;
  line-height: 1.78;
  color: var(--muted);
}

.guide-pitfalls .pitfall-item {
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-sm);
  margin-bottom: 10px;
  overflow: hidden;
}

.pitfall-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 18px;
  font-size: 15px;
  font-weight: 500;
  line-height: 1.6;
  color: var(--ink);
  cursor: pointer;
  list-style: none;
}

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

.pitfall-summary::after {
  content: "+";
  flex-shrink: 0;
  font-size: 18px;
  font-weight: 400;
  line-height: 1;
  color: var(--brand);
}

.pitfall-item[open] .pitfall-summary::after {
  content: "−";
}

.pitfall-summary:hover {
  color: var(--brand);
}

.pitfall-body {
  padding: 0 18px 16px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.pitfall-body a {
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.pitfall-body a:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

.next-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
}

.next-link-item a {
  font-size: 14px;
  font-weight: 500;
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.next-link-item a:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

/* 入口核验 */
.check-summary .summary-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.check-summary .summary-item {
  flex-direction: row;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 14px;
}

.check-summary .summary-text {
  flex: 1 1 320px;
  min-width: 0;
}

.check-figure {
  max-width: 900px;
}

.check-figure .figure-media img {
  width: 100%;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line-soft);
}

.symptom-rows {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.symptom-row {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1.4fr) minmax(0, 1.6fr) minmax(0, 1.1fr);
  gap: 0;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  overflow: hidden;
}

.symptom-field {
  padding: 16px;
  border-left: 1px solid var(--line-soft);
  min-width: 0;
}

.symptom-field:first-child {
  border-left: 0;
}

.symptom-name {
  display: flex;
  align-items: center;
  background-color: rgba(15, 90, 87, 0.05);
}

.symptom-title {
  font-size: 16px;
  line-height: 1.5;
}

.symptom-row .field-label {
  margin-bottom: 4px;
}

.handle-steps .step {
  padding: 18px 20px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  margin-bottom: 14px;
}

.handle-steps .step:last-child {
  margin-bottom: 0;
}

.handle-steps .step-title {
  font-size: 17px;
  line-height: 1.5;
}

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

.handle-steps .step-site {
  border-left: 3px solid var(--brand);
}

.handle-steps .step-user {
  border-left: 3px solid var(--accent);
}

.boundary-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.boundary-item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 14px;
  padding: 14px 16px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
}

.boundary-text {
  flex: 1 1 320px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink);
  min-width: 0;
}

.check-faq .faq-item {
  margin-bottom: 10px;
}

/* 反馈说明 */
.feedback-scope .scope-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.scope-item {
  padding: 18px 20px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
}

.scope-item-title {
  font-size: 16px;
  line-height: 1.5;
  margin-bottom: 6px;
}

.scope-item p {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.info-figure {
  max-width: 900px;
}

.info-figure-media img {
  width: 100%;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line-soft);
}

.preparation-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.preparation-item {
  padding: 14px 16px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-sm);
}

.preparation-item-title {
  font-size: 16px;
  line-height: 1.5;
  margin-bottom: 4px;
}

.preparation-item p {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.preparation-item p a {
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.preparation-item p a:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

.field-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.field-card {
  padding: 18px 20px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
}

.field-card-title {
  font-size: 16px;
  line-height: 1.5;
  margin-bottom: 6px;
}

.field-card p {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.path-steps {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.path-step {
  padding: 16px 18px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
}

.path-step-title {
  font-size: 16px;
  line-height: 1.5;
  margin-bottom: 8px;
}

.path-step-fields {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px 20px;
}

.path-field {
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink);
  min-width: 0;
}

.path-field-label {
  display: block;
  font-size: 12px;
  font-weight: 500;
  line-height: 1.6;
  color: var(--accent-deep);
  margin-bottom: 2px;
}

.precheck-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
}

.precheck-item a {
  font-size: 14px;
  font-weight: 500;
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.precheck-item a:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

/* 内容准则 */
.page-shell {
  max-width: 900px;
}

.page-shell > section,
.page-shell > figure {
  margin-bottom: 38px;
}

.page-shell > section:last-of-type {
  margin-bottom: 0;
}

.rule-figure {
  max-width: 900px;
}

.rule-figure-media img {
  width: 100%;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line-soft);
}

.standards-summary .summary-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.standards-summary .summary-item {
  flex-direction: row;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 14px;
  border-left-color: var(--brand);
}

.standards-summary .summary-text {
  flex: 1 1 320px;
  min-width: 0;
}

.rule-list {
  display: flex;
  flex-direction: column;
  gap: 0;
  border-top: 1px solid var(--line-soft);
}

.rule-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 2fr);
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line-soft);
}

.rule-title {
  font-family: var(--font-serif);
  font-size: 16px;
  font-weight: 600;
  line-height: 1.6;
  color: var(--ink);
}

.rule-desc {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  min-width: 0;
}

.annotation-table {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background-color: var(--surface);
}

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

.annotation-row:first-child {
  border-top: 0;
}

.annotation-head {
  background-color: rgba(15, 90, 87, 0.07);
}

.annotation-cell {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 13px 16px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink);
  border-left: 1px solid var(--line-soft);
  min-width: 0;
}

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

.annotation-head .annotation-cell {
  font-size: 13px;
  font-weight: 500;
  color: var(--brand);
}

.annotation-label {
  font-weight: 500;
  color: var(--ink);
}

.annotation-note {
  font-size: 13px;
  color: var(--muted);
}

.related-link-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 24px;
}

.related-link-item {
  font-size: 14px;
}

/* 常见问题 */
.faq-figure-section {
  max-width: 820px;
}

.faq-figure {
  max-width: 820px;
}

.faq-figure-media img {
  width: 100%;
  aspect-ratio: 16 / 6;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line-soft);
}

.faq-layout {
  max-width: 820px;
  display: flex;
  flex-direction: column;
  gap: 34px;
}

.faq-group {
  scroll-margin-top: 90px;
}

.faq-group .faq-item {
  margin-bottom: 10px;
}

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

.faq .related-entry,
.faq-layout + .related-entry {
  max-width: 820px;
}

.related-entry .related-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 24px;
  margin: 0;
  padding: 16px 0 0;
  border-top: 1px solid var(--line-soft);
}

.related-entry .related-links li a {
  font-size: 14px;
  font-weight: 500;
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.related-entry .related-links li a:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

/* --------------------------------------------------------------------------
   4. pages · 404
   -------------------------------------------------------------------------- */

.error-main {
  max-width: 900px;
  margin: 0 auto;
  padding: 56px var(--gutter) 72px;
}

.error-panel {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding-bottom: 34px;
  border-bottom: 1px solid var(--line-soft);
}

.error-code {
  font-family: var(--font-serif);
  font-size: 56px;
  font-weight: 600;
  line-height: 1;
  color: var(--accent);
}

.error-title {
  font-size: clamp(24px, 3vw, 32px);
  line-height: 1.35;
}

.error-lead {
  font-size: 16px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 640px;
}

.error-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 22px;
  margin-top: 6px;
}

.error-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  font-size: 15px;
  font-weight: 500;
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.error-link:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

.error-guide {
  padding-top: 32px;
}

.error-guide-title {
  font-size: 20px;
  line-height: 1.4;
  margin-bottom: 18px;
}

.error-path-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.error-path-item {
  padding: 16px 18px;
  background-color: var(--surface);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
}

.error-path-name {
  font-size: 16px;
  line-height: 1.5;
  margin-bottom: 4px;
}

.error-path-desc {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  margin-bottom: 6px;
}

.error-path-link {
  font-size: 14px;
  font-weight: 500;
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.error-path-link:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

.error-note {
  margin-top: 26px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.error-note a {
  color: var(--brand);
  border-bottom: 1px solid var(--mint);
}

.error-note a:hover {
  color: var(--accent-deep);
  border-bottom-color: var(--accent);
}

/* --------------------------------------------------------------------------
   5. responsive
   -------------------------------------------------------------------------- */

@media (max-width: 960px) {
  :root {
    --gutter: 20px;
  }

  .header-inner {
    flex-wrap: wrap;
    gap: 10px 14px;
  }

  .nav-toggle {
    display: flex;
    order: 3;
  }

  .site-nav {
    order: 4;
    flex-basis: 100%;
  }

  .nav-list {
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 6px 0 10px;
    border-top: 1px solid var(--line-soft);
  }

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

  .nav-link {
    display: block;
    padding: 11px 4px;
    border-bottom: 1px solid var(--line-soft);
    border-radius: 0;
    font-size: 15px;
  }

  .nav-link.is-current {
    border-bottom-color: var(--brand);
  }

  .header-actions {
    margin-left: auto;
  }

  .hero {
    grid-template-columns: minmax(0, 1fr);
    gap: 26px;
    padding: 30px 0 36px;
  }

  .hero-media {
    order: 2;
  }

  .channel-grid,
  .feature-grid,
  .check-grid,
  .advice-grid,
  .feedback-scope .scope-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .home-main .guide-summary .summary-list {
    grid-template-columns: minmax(0, 1fr);
  }

  .channel-row {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.6fr) minmax(0, 1fr) minmax(0, 1fr);
  }

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

  .symptom-field:nth-child(3) {
    border-left: 0;
  }

  .symptom-field:nth-child(3),
  .symptom-field:nth-child(4) {
    border-top: 1px solid var(--line-soft);
  }

  .topic-card,
  .topic-card:nth-child(even) {
    grid-template-columns: minmax(0, 1fr);
    gap: 16px;
  }

  .topic-card:nth-child(even) .media,
  .topic-card:nth-child(even) .topic-copy {
    order: 0;
  }

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

@media (max-width: 680px) {
  :root {
    --gutter: 16px;
  }

  body {
    font-size: 16px;
  }

  .header-inner {
    padding: 10px var(--gutter);
  }

  .brand-mark {
    font-size: 19px;
  }

  .brand-slogan {
    font-size: 11px;
  }

  .btn-command {
    min-height: 44px;
    padding: 8px 14px;
    font-size: 13px;
  }

  .inner-main {
    padding-bottom: 48px;
  }

  .breadcrumb {
    padding: 14px 0 2px;
  }

  .page-title-block,
  section.page-title {
    padding: 10px 0 20px;
    margin-bottom: 26px;
  }

  .page-lead {
    font-size: 16px;
  }

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

  .hero-copy h1 {
    font-size: 27px;
  }

  .hero-lead {
    font-size: 16px;
  }

  .hero-actions {
    gap: 10px 18px;
  }

  .channel-matrix,
  .feature-collections,
  .content-flow,
  .entry-check-teaser,
  .guide-summary,
  .faq {
    padding-top: 36px;
  }

  .channel-grid,
  .feature-grid,
  .check-grid,
  .advice-grid,
  .feedback-scope .scope-list,
  .field-grid,
  .bridge-columns,
  .related-grid {
    grid-template-columns: minmax(0, 1fr);
  }

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

  .channel-table {
    border: 0;
    background-color: transparent;
    overflow: visible;
  }

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

  .channel-row {
    display: flex;
    flex-direction: column;
    background-color: var(--surface);
    border: 1px solid var(--line-soft);
    border-radius: var(--radius);
    margin-bottom: 12px;
    overflow: hidden;
  }

  .channel-cell {
    border-left: 0;
    border-top: 1px solid var(--line-soft);
    padding: 10px 14px;
  }

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

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

  .cell-scope::before {
    content: "内容范围";
    display: block;
    font-size: 12px;
    font-weight: 500;
    color: var(--accent-deep);
    margin-bottom: 2px;
  }

  .cell-topic::before {
    content: "适合专题";
    display: block;
    font-size: 12px;
    font-weight: 500;
    color: var(--accent-deep);
    margin-bottom: 2px;
  }

  .cell-next::before {
    content: "下一步入口";
    display: block;
    font-size: 12px;
    font-weight: 500;
    color: var(--accent-deep);
    margin-bottom: 2px;
  }

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

  .symptom-field {
    border-left: 0;
    border-top: 1px solid var(--line-soft);
  }

  .symptom-field:first-child {
    border-top: 0;
  }

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

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

  .annotation-head {
    display: none;
  }

  .annotation-row {
    border-top: 1px solid var(--line-soft);
    padding: 4px 0;
  }

  .annotation-row:first-child {
    border-top: 0;
  }

  .annotation-cell {
    border-left: 0;
    padding: 8px 14px;
  }

  .footer-inner {
    padding: 36px var(--gutter) 22px;
  }

  .footer-cta-text {
    font-size: 18px;
  }

  .footer-columns {
    grid-template-columns: minmax(0, 1fr);
    gap: 22px;
    padding: 24px 0 20px;
  }

  .footer-links a {
    padding: 4px 0;
  }

  .error-main {
    padding: 40px var(--gutter) 56px;
  }

  .error-code {
    font-size: 44px;
  }

  .related-links {
    margin-top: 28px;
  }
}

@media (max-width: 480px) {
  .hero-copy h1 {
    font-size: 24px;
    line-height: 1.3;
  }

  .btn-primary,
  .link-secondary {
    width: 100%;
    justify-content: center;
  }

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

  .btn-command {
    padding: 8px 12px;
  }

  .channel-card,
  .check-card,
  .advice-item,
  .bridge-card,
  .related-col,
  .field-card,
  .scope-item {
    padding: 16px;
  }

  .card-copy {
    padding: 14px 16px 18px;
  }

  .faq-question,
  .pitfall-summary {
    padding: 13px 14px;
    font-size: 14px;
  }

  .faq-answer,
  .pitfall-body {
    padding: 0 14px 14px;
  }

  .topic-card {
    padding: 16px;
  }

  .summary-item,
  .channel-conclusion .conclusion-item,
  .order-item,
  .boundary-item {
    padding: 12px 14px;
  }

  .content-flow .step,
  .guide-principle .step,
  .handle-steps .step,
  .guide-example .example-item,
  .path-step {
    padding: 14px 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}