/*
 * 新华美育 · 静态归档展示站
 * 视觉基准：https://www.xinhuameiyu.com/
 * 说明：页面仅复刻公开前端展示层；图片、图标等媒体资源全部引用原站绝对 URL。
 */

:root {
  --ink: #000;
  --text: #333;
  --muted: #999;
  --line: #e0e0e0;
  --soft: #f5f5f5;
  --soft-pink: #f6f3f3;
  --header: #3a3a3a;
  --footer-text: #797979;
  --brand-blue: #337ab7;
  --brand-cyan: #3eafe0;
  --wrap: 1104px;
}

* {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  min-height: 100vh;
  margin: 0;
  font-family: "Helvetica Neue", Helvetica, "Microsoft Yahei", "Hiragino Sans GB",
    "WenQuanYi Micro Hei", sans-serif;
  font-size: 14px;
  line-height: 1.42857143;
  color: var(--ink);
  background: #fff;
}

body.modal-open {
  overflow: hidden;
}

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

a:hover,
a:focus {
  color: var(--ink);
  text-decoration: none;
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid rgba(51, 122, 183, 0.65);
  outline-offset: 2px;
}

img {
  max-width: 100%;
  border: 0;
  vertical-align: middle;
}

button,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

[hidden] {
  display: none !important;
}

.wrap {
  width: var(--wrap);
  max-width: 100%;
  margin: 0 auto;
}

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

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 9999;
  padding: 10px 16px;
  background: #fff;
  color: #000;
}

.skip-link:focus {
  left: 8px;
  top: 8px;
}

/* ============================== Header ============================== */

.site-header {
  position: relative;
  z-index: 100;
  height: 50px;
  min-width: 1104px;
  background: var(--header);
}

.header-inner {
  width: var(--wrap);
  max-width: 100%;
  height: 50px;
  margin: 0 auto;
  display: flex;
  align-items: center;
}

.brand {
  flex: 0 0 auto;
  display: block;
  height: 50px;
  margin-right: 50px;
}

.brand img {
  display: block;
  width: 168px;
  height: 50px;
}

.brand-text {
  display: flex;
  align-items: center;
  height: 50px;
  padding-left: 4px;
  font-size: 23px;
  font-weight: 500;
  letter-spacing: 2px;
  color: #fff;
  white-space: nowrap;
}

.nav-panel {
  min-width: 0;
  flex: 1;
  display: flex;
  align-items: center;
}

.main-nav {
  display: flex;
  align-items: center;
  margin: 0;
  padding: 0;
  list-style: none;
}

.main-nav a {
  display: block;
  padding: 0 10px;
  font-size: 16px;
  line-height: 50px;
  color: #fff;
  white-space: nowrap;
}

.main-nav a:hover,
.main-nav a:focus {
  color: #fff;
  background: #4a4a4a;
}

.submit-link {
  margin-left: auto;
  padding: 0 10px;
  font-size: 16px;
  line-height: 50px;
  color: #fff;
  white-space: nowrap;
}

.submit-link:hover,
.submit-link:focus {
  color: #fff;
}

.nav-toggle {
  display: none;
  width: 44px;
  height: 44px;
  margin-left: auto;
  padding: 0;
  border: 0;
  background: transparent;
  color: #fff;
}

.nav-toggle span,
.nav-toggle::before,
.nav-toggle::after {
  display: block;
  width: 22px;
  height: 2px;
  margin: 5px auto;
  background: currentColor;
  content: "";
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.nav-toggle[aria-expanded="true"] span {
  opacity: 0;
}

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

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

/* ============================== Footer ============================== */

.site-footer {
  margin-top: 0;
  padding: 40px 16px;
  background: var(--header);
  color: var(--footer-text);
  font-size: 14px;
  line-height: 200%;
  text-align: center;
}

.site-footer a {
  color: var(--footer-text);
}

.site-footer a:hover {
  color: #b7b7b7;
}

.footer-police {
  display: inline-flex;
  align-items: center;
  vertical-align: middle;
  line-height: 20px;
}

.footer-police img {
  width: 20px;
  height: 20px;
  margin-right: 5px;
}

.back-to-top {
  position: fixed;
  right: 22px;
  bottom: 24px;
  z-index: 80;
  width: 44px;
  height: 44px;
  padding: 0;
  font-size: 20px;
  line-height: 42px;
  color: var(--brand-blue);
  text-align: center;
  cursor: pointer;
  background: rgba(255, 255, 255, 0.96);
  border: 1px solid rgba(51, 122, 183, 0.3);
  border-radius: 50%;
  box-shadow: 0 6px 18px rgba(30, 50, 70, 0.16);
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease;
}

.back-to-top:hover {
  color: #fff;
  background: var(--brand-blue);
  border-color: var(--brand-blue);
}

.back-to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

@media (max-width: 640px) {
  .back-to-top {
    right: 14px;
    bottom: 16px;
    width: 40px;
    height: 40px;
    line-height: 38px;
    font-size: 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .back-to-top {
    transition: none;
  }
}

.footer-sep {
  margin: 0 3px;
}

/* ============================== Home ============================== */

.home-main {
  flex: 1 0 auto;
}

.hero {
  position: relative;
  height: 438px;
  min-width: 1104px;
  overflow: hidden;
  background: #fff;
}

.hero a,
.hero img {
  display: block;
  width: 100%;
  height: 100%;
}

.hero img {
  object-fit: cover;
  object-position: center;
}

.home-module {
  padding: 70px 0 90px;
  text-align: center;
  background: #fff;
}

.home-module.is-soft {
  background: var(--soft-pink);
}

.module-title {
  width: 380px;
  height: 40px;
  margin: 0 auto 35px;
  font-size: 40px;
  font-weight: 100;
  line-height: 50px;
  color: var(--text);
}

.home-cards {
  display: flex;
  flex-wrap: nowrap;
  justify-content: center;
  align-items: flex-start;
  padding: 0 20px;
}

.home-card {
  flex: 0 0 170px;
  width: 170px;
  height: 170px;
  margin: 0 20px;
  display: block;
  overflow: hidden;
}

.home-card img {
  display: block;
  width: 170px;
  height: 170px;
  object-fit: cover;
  transition: transform 0.35s ease, box-shadow 0.35s ease;
}

.home-card:hover img,
.home-card:focus img {
  transform: scale(1.035);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

/* ============================== Shared page furniture ============================== */

.page-main {
  flex: 1 0 auto;
}

.page-soft {
  background: var(--soft);
}

.page-inner {
  padding-bottom: 40px;
}

.crumbs {
  padding: 20px 0;
  font-size: 14px;
  line-height: 1.4;
  color: var(--ink);
}

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

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

.page-banner {
  height: 338px;
  min-width: 1104px;
  overflow: hidden;
  background: #dfd9db;
}

.page-banner img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

/* ============================== Category / filters ============================== */

.cat {
  padding: 20px 15px 0;
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--line);
}

.cat p {
  padding: 0 0 10px;
  margin: 0;
  overflow: hidden;
  border-bottom: 1px dashed var(--line);
}

.cat p:last-child {
  border-bottom: 0;
}

.cat .title {
  float: left;
  width: 120px;
  margin: 0 10px 1px 0;
  padding: 3px 5px;
  font-size: 16px;
  color: var(--text);
  text-align: center;
  background: #ddd;
  border-radius: 3px;
}

.cat .title.here,
.cat .title.is-active {
  color: #fff;
  background: var(--brand-blue);
}

.cat .c {
  float: left;
  margin: 0 14px 0 0;
  padding: 4px 8px;
  font-size: 14px;
  line-height: 1.5;
  color: var(--ink);
  border-radius: 3px;
  transition: color 0.2s ease, background-color 0.2s ease;
}

.cat .c:hover {
  color: var(--brand-blue);
  background: #f0f6fb;
}

.cat .c.here,
.cat .c.is-active {
  color: #fff;
  background: var(--brand-blue);
  border-radius: 3px;
}

.filter-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 12px 0 10px;
  margin-top: 0;
  border-top: 1px dashed var(--line);
}

.filter-row label {
  margin: 0;
  font-weight: 400;
}

.filter-row input {
  flex: 1 1 170px;
  width: auto;
  min-width: 130px;
  height: 32px;
  padding: 5px 10px;
  font-size: 14px;
  color: #555;
  background: #fff;
  border: 1px solid #ccc;
  border-radius: 3px;
  outline: 0;
}

.filter-row input:focus {
  border-color: #66afe9;
  box-shadow: 0 0 6px rgba(102, 175, 233, 0.45);
}

.btn-primary {
  display: inline-block;
  padding: 5px 12px;
  font-size: 14px;
  color: #fff;
  background: var(--brand-blue);
  border: 1px solid #2e6da4;
  border-radius: 3px;
}

.btn-primary:hover {
  color: #fff;
  background: #286090;
}

.filter-count {
  margin-left: 6px;
  font-size: 12px;
  color: var(--muted);
}

.broadcast-card {
  height: auto;
}

/* ============================== Course list ============================== */

.course-section {
  margin-top: 0;
}

.course-item {
  display: block;
  margin-top: 25px;
  padding: 20px;
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--line);
  transition: box-shadow 0.25s ease;
}

.course-item:hover,
.course-item:focus {
  box-shadow: 0 3px 14px rgba(0, 0, 0, 0.08);
}

.course-cover {
  float: left;
  width: 260px;
  height: auto;
  aspect-ratio: 400 / 254;
  overflow: hidden;
  background: #f3f3f3;
}

.course-cover img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.course-info {
  float: left;
  width: calc(100% - 290px);
  padding-left: 30px;
}

.course-title {
  margin: 0 0 16px;
  overflow: hidden;
  font-size: 24px;
  font-weight: 200;
  line-height: 1.15;
  color: var(--text);
  white-space: nowrap;
  text-overflow: ellipsis;
}

.course-author {
  display: flex;
  align-items: center;
  margin: 0 0 10px;
  padding-right: 15px;
  overflow: hidden;
  font-size: 16px;
  color: var(--muted);
  white-space: nowrap;
  text-overflow: ellipsis;
}

.course-author img {
  flex: 0 0 32px;
  width: 32px;
  height: 32px;
  margin-right: 10px;
  object-fit: cover;
  border-radius: 50%;
}

.course-brief {
  display: -webkit-box;
  height: 60px;
  margin: 0 0 10px;
  overflow: hidden;
  font-size: 12px;
  line-height: 20px;
  color: var(--muted);
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
}

.course-meta {
  margin: 0;
  font-size: 14px;
  line-height: 30px;
  color: var(--ink);
}

.enter {
  float: right;
  display: block;
  width: 94px;
  height: 30px;
  font-size: 14px;
  font-weight: bold;
  line-height: 30px;
  color: #fff !important;
  text-align: center;
  background: var(--brand-cyan);
  border-radius: 2px;
}

.course-item:hover .enter,
.course-item:focus .enter {
  background: #d98c1d;
}

/* ============================== Grid cards (activities / broadcasts) ============================== */

.activities-page {
  background: var(--soft);
}

.activities-page .page-inner {
  padding-bottom: 50px;
}

.activities-page .cat {
  padding: 10px 20px;
}

.activities-page .cat p {
  padding: 0;
  border: 0;
}

.activities-page .cat .c {
  padding: 8px 12px;
  margin-right: 14px;
}

.content-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
  margin-top: 25px;
}

.content-card {
  display: flex;
  flex-direction: column;
  min-width: 0;
  height: 100%;
  padding: 20px;
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--line);
  transition: box-shadow 0.25s ease, transform 0.25s ease;
}

.content-card:hover,
.content-card:focus-within {
  box-shadow: 0 8px 24px rgba(30, 50, 70, 0.12);
  transform: translateY(-2px);
}

.card-cover {
  position: relative;
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 260 / 165;
  overflow: hidden;
  background: #eee;
  border-radius: 3px;
}

.card-cover img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.content-card:hover .card-cover img {
  transform: scale(1.04);
}

.card-caption {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 12px;
  color: #fff;
  text-align: center;
  background: rgba(44, 62, 80, 0.92);
  opacity: 0;
  transition: opacity 0.35s ease;
}

.content-card:hover .card-caption,
.content-card:focus-within .card-caption {
  opacity: 1;
}

.card-caption strong {
  display: block;
  margin-bottom: 8px;
  font-size: 22px;
  color: #fff;
}

.card-caption span {
  font-size: 14px;
  line-height: 1.5;
  color: #fff;
}

.content-card .card-title {
  margin: 10px 0;
  font-size: 20px;
  font-weight: 400;
  line-height: 1.4;
  color: var(--text);
  overflow: hidden;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.content-card .card-title a {
  color: var(--text);
}

.content-card .card-title a:hover {
  color: var(--brand-blue);
}

.content-card .card-brief {
  margin: 6px 0 0;
  padding-top: 2px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
}

.content-card .card-brief:last-child {
  margin-top: auto;
}

.item-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 5px;
  margin: 10px 0 5px;
}

.item-tags a {
  display: inline-block;
  max-width: 100%;
  padding: 0 9px;
  overflow: hidden;
  font-size: 13px;
  line-height: 22px;
  color: #fff;
  text-overflow: ellipsis;
  white-space: nowrap;
  background: #aab5c3;
  border-radius: 11px;
  transition: filter 0.2s ease;
}

.item-tags a:first-child {
  background: #ff8000;
}

.item-tags a:last-child {
  background: #00a2e3;
}

.item-tags a:hover {
  color: #fff;
  filter: brightness(0.94);
}

.card-meta {
  margin: 4px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

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

.card-meta a:hover {
  color: var(--brand-blue);
}

.activity-cat a {
  display: inline-block;
}

.activity-cat .c {
  padding: 3px 5px;
}

.activity-empty,
.ap-filter-empty {
  margin: 30px 0 0;
  padding: 48px 24px;
  font-size: 16px;
  color: #888;
  text-align: center;
  background: #fff;
  border: 1px solid var(--line);
}

.ap-filter-empty {
  display: none;
  margin-top: 25px;
}

.ap-filter-empty.is-visible {
  display: block;
}

/* ============================== Pagination ============================== */

.pager {
  margin: 30px 0 0;
  text-align: center;
}

.pagination {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 6px 0;
  margin: 0;
  padding: 0;
  list-style: none;
}

.pagination > li {
  display: inline-block;
}

.pagination > li > a,
.pagination > li > span,
.pager-total {
  display: inline-block;
  padding: 5px 14px;
  margin-left: -1px;
  font-size: 14px;
  line-height: 1.75;
  color: #666;
  background: #fff;
  border: 1px solid #ddd;
}

.pagination > li:first-child > a {
  margin-left: 0;
  border-radius: 4px 0 0 4px;
}

.pagination > li:last-child > a {
  border-radius: 0 4px 4px 0;
}

.pagination > li.active > span {
  color: var(--brand-blue);
  background: var(--soft);
  border-color: #ddd;
  cursor: default;
}

.pagination a:hover {
  color: var(--brand-blue);
  background: #eee;
}

.pagination .is-disabled {
  color: #bbb;
  cursor: not-allowed;
}

.pagination .is-ellipsis {
  padding: 5px 6px;
  color: #999;
  background: transparent;
  border-color: transparent;
}

.pager-loading {
  margin: 0;
  font-size: 13px;
  line-height: 1.8;
  color: var(--muted);
  text-align: center;
}

.static-page-note {
  margin: 0 0 14px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
  text-align: center;
}

.static-page-note a {
  margin-left: 6px;
  color: var(--brand-blue);
}

.pager-total {
  margin: 12px 0 0;
  padding: 4px 10px;
  color: var(--muted);
  background: transparent;
  border: 0;
}

/* ============================== Art & Tech / About ============================== */

.single-course-wrap {
  padding-bottom: 40px;
}

.arttech-note {
  margin-top: 25px;
  padding: 18px 22px;
  font-size: 14px;
  line-height: 1.8;
  color: #6f6f6f;
  background: #fff;
  border: 1px solid var(--line);
}

.about-page {
  background: var(--soft);
}

.about-shell {
  padding: 20px 20px 60px;
  background: #fff;
  border: 1px solid var(--line);
}

.about-title {
  margin: 10px auto 20px;
  font-size: 24px;
  font-weight: 100;
  text-align: center;
}

.about-empty {
  max-width: 800px;
  margin: 20px auto 0;
  padding: 48px 24px;
  font-size: 15px;
  line-height: 1.9;
  color: #888;
  text-align: center;
  border: 1px dashed #ddd;
}

/* ============================== Detail shells ============================== */

.detail-page {
  background: var(--soft);
}

.detail-page .page-inner {
  padding-bottom: 50px;
}

.detail-shell {
  padding: 20px;
  background: #fff;
  border: 1px solid var(--line);
}

.detail-title {
  margin: 30px auto 20px;
  font-size: 24px;
  font-weight: 100;
  text-align: center;
}

.detail-meta {
  max-width: 800px;
  margin: 18px auto 0;
  padding-bottom: 24px;
  font-size: 16px;
  color: #888;
  text-align: center;
  border-bottom: 1px solid #ddd;
}

.detail-content {
  max-width: 800px;
  min-height: 300px;
  margin: 0 auto;
  padding: 40px 0 20px;
  font-size: 16px;
  font-weight: 100;
  line-height: 2;
}

.archive-placeholder {
  margin: 30px auto;
  padding: 54px 24px;
  text-align: center;
  border: 1px dashed #d8d8d8;
  background: #fafafa;
}

.archive-placeholder .ph-icon {
  display: block;
  width: 54px;
  height: 54px;
  margin: 0 auto 18px;
  font-size: 28px;
  line-height: 54px;
  color: #aaa;
  border: 1px solid #d5d5d5;
  border-radius: 50%;
}

.archive-placeholder h2 {
  margin: 0 0 12px;
  font-size: 20px;
  font-weight: 400;
  color: #555;
}

.archive-placeholder p {
  max-width: 620px;
  margin: 0 auto;
  font-size: 14px;
  line-height: 1.9;
  color: #888;
}

.back-link {
  display: inline-block;
  margin-top: 22px;
  padding: 7px 18px;
  font-size: 14px;
  color: #fff !important;
  background: var(--brand-blue);
  border-radius: 3px;
}

.back-link:hover {
  background: #286090;
}

/* ============================== Archived detail content ============================== */

.detail-archived {
  background: var(--soft);
}

.detail-archived .page-inner {
  padding-bottom: 50px;
}

.course-article,
.article-card {
  padding: 20px;
  background: #fff;
  border: 1px solid var(--line);
}

.course-intro {
  overflow: hidden;
}

.course-cover-large {
  float: left;
  display: block;
  width: 400px;
  max-width: 100%;
  height: 254px;
  overflow: hidden;
  background: #111;
}

.course-cover-large img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
  background: #f3f3f3;
}

.course-intro-info {
  float: left;
  width: calc(100% - 430px);
  min-height: 254px;
  padding-left: 30px;
}

.course-category {
  display: inline-block;
  padding: 2px 9px;
  margin: 0 0 10px;
  font-size: 12px;
  line-height: 20px;
  color: #fff;
  background: var(--brand-blue);
  border-radius: 10px;
}

.course-intro-info h1 {
  margin: 2px 0 14px;
  font-size: 24px;
  font-weight: 300;
  line-height: 1.4;
  color: var(--text);
}

.course-intro-label {
  margin: 0 0 6px;
  font-size: 15px;
  font-weight: bold;
  color: var(--text);
}

.course-intro-brief {
  margin: 0 0 18px;
  font-size: 14px;
  line-height: 1.9;
  color: #666;
}

.course-statline {
  padding-top: 14px;
  margin-top: auto;
  font-size: 14px;
  color: var(--muted);
  border-top: 1px solid #eee;
}

.course-statline strong {
  font-weight: 400;
  color: #666;
}

.course-source-link {
  display: inline-block;
  margin-top: 12px;
  font-size: 13px;
  color: var(--brand-blue) !important;
}

.course-source-link:hover {
  text-decoration: underline;
}

.course-layout {
  display: grid;
  grid-template-columns: minmax(0, 812px) 274px;
  gap: 18px;
  margin-top: 20px;
  align-items: start;
}

.course-catalog,
.teacher-card {
  min-width: 0;
  padding: 20px;
  background: #fff;
  border: 1px solid var(--line);
}

.catalog-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
  padding-bottom: 12px;
  margin-bottom: 14px;
  border-bottom: 1px solid #eee;
}

.catalog-title {
  margin: 0;
  font-size: 20px;
  font-weight: 400;
  color: var(--text);
}

.catalog-count {
  font-size: 13px;
  color: var(--muted);
}

.catalog-note {
  padding: 9px 12px;
  margin: 0 0 16px;
  font-size: 12px;
  line-height: 1.8;
  color: #777;
  background: #fafafa;
  border-left: 3px solid #dcdcdc;
}

.catalog-note a {
  color: var(--brand-blue);
}

.chapter-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
}

.chapter-card {
  position: relative;
  display: block;
  min-width: 0;
  padding: 10px;
  overflow: hidden;
  background: #f6f6f6;
  border: 1px solid #eee;
  transition: box-shadow 0.2s ease, background 0.2s ease;
}

.chapter-card:hover,
.chapter-card:focus {
  background: #f1f6fb;
  box-shadow: 0 3px 12px rgba(0, 0, 0, 0.08);
}

.chapter-thumb {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 220 / 180;
  overflow: hidden;
  background: #e9e9e9;
}

.chapter-thumb img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.35s ease;
}

.chapter-card:hover .chapter-thumb img {
  transform: scale(1.035);
}

.chapter-play {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 38px;
  height: 38px;
  margin: -19px 0 0 -19px;
  border: 2px solid rgba(255, 255, 255, 0.9);
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.28);
}

.chapter-play::after {
  position: absolute;
  left: 14px;
  top: 10px;
  display: block;
  width: 0;
  height: 0;
  content: "";
  border-top: 7px solid transparent;
  border-bottom: 7px solid transparent;
  border-left: 10px solid #fff;
}

.chapter-title {
  display: -webkit-box;
  height: 42px;
  margin: 9px 0 4px;
  overflow: hidden;
  font-size: 14px;
  font-weight: bold;
  line-height: 1.5;
  color: var(--text);
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.chapter-duration {
  display: block;
  font-size: 12px;
  color: var(--muted);
}

.teacher-card {
  position: sticky;
  top: 16px;
}

.teacher-card img {
  display: block;
  width: 140px;
  height: 140px;
  margin: 4px auto 18px;
  object-fit: cover;
  border-radius: 50%;
  background: #eee;
}

.teacher-name {
  margin: 0 0 14px;
  font-size: 17px;
  font-weight: bold;
  text-align: center;
  color: var(--text);
}

.teacher-card .teacher-label {
  padding-top: 14px;
  margin-top: 14px;
  font-size: 13px;
  color: var(--muted);
  border-top: 1px solid #eee;
}

.teacher-bio {
  margin: 0;
  font-size: 13px;
  line-height: 1.9;
  color: #666;
}

.article-title {
  max-width: 900px;
  margin: 30px auto 18px;
  font-size: 25px;
  font-weight: 300;
  line-height: 1.45;
  text-align: center;
  color: var(--text);
  overflow-wrap: anywhere;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 4px 8px;
  width: 800px;
  max-width: 100%;
  margin: 0 auto;
  padding-bottom: 28px;
  font-size: 16px;
  line-height: 1.8;
  color: #888;
  text-align: center;
  border-bottom: 1px solid #ddd;
}

.article-content {
  width: 800px;
  max-width: 100%;
  margin: 0 auto;
  padding: 40px 0 20px;
  overflow-wrap: break-word;
  font-size: 16px;
  line-height: 2;
  color: var(--text);
}

.article-content p {
  margin: 0 0 12px;
}

.article-content img {
  max-width: 100%;
  height: auto;
}

.article-content table {
  max-width: 100%;
  border-collapse: collapse;
}

.article-content td,
.article-content th {
  padding: 4px;
}

.article-content iframe,
.article-content video {
  max-width: 100%;
  border: 0;
}

.article-video {
  margin: 0 0 26px;
  overflow: hidden;
  background: #000;
  border-radius: 6px;
  box-shadow: 0 10px 28px rgba(20, 35, 50, 0.16);
}

.article-video video {
  display: block;
  width: 100%;
  max-height: 72vh;
  background: #000;
}

.article-media-note {
  padding: 12px;
  margin: 12px 0;
  font-size: 13px;
  color: #888;
  text-align: center;
  background: #fafafa;
  border: 1px dashed #ddd;
}

.article-footer {
  width: 800px;
  max-width: 100%;
  margin: 20px auto 0;
  padding-top: 20px;
  font-size: 12px;
  line-height: 1.8;
  color: #999;
  text-align: center;
  border-top: 1px solid #eee;
}

.article-back {
  display: block;
  width: fit-content;
  margin: 24px auto 0;
  padding: 7px 18px;
  font-size: 14px;
  color: #fff !important;
  background: var(--brand-blue);
  border-radius: 3px;
}

.article-back:hover {
  background: #286090;
}

/* ============================== Chapter video page ============================== */

.chapter-page {
  background: var(--soft);
}

.chapter-page .page-inner {
  padding-bottom: 50px;
}

.chapter-layout {
  display: grid;
  grid-template-columns: 647px 440px;
  gap: 17px;
  margin-top: 20px;
  align-items: start;
}

.chapter-main,
.chapter-side {
  min-width: 0;
}

.chapter-player {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  aspect-ratio: 647 / 402;
  overflow: hidden;
  background: #000;
}

.chapter-player video {
  display: block;
  width: 100%;
  height: 100%;
  background: #000;
  object-fit: contain;
}

.chapter-player video::-internal-media-controls-download-button,
.media-stage video::-internal-media-controls-download-button {
  display: none;
}

.chapter-player video::-webkit-media-controls-download-button,
.media-stage video::-webkit-media-controls-download-button {
  display: none;
}

.chapter-player audio {
  display: block;
  width: 88%;
  max-width: 600px;
}

.chapter-player-loading,
.chapter-player-fallback {
  padding: 24px;
  font-size: 14px;
  line-height: 1.9;
  color: #ddd;
  text-align: center;
}

.chapter-player-fallback a {
  color: #8ec5ff;
}

.chapter-content {
  min-height: 300px;
  padding: 50px 20px 20px;
  margin-top: 15px;
  overflow-wrap: break-word;
  font-size: 16px;
  line-height: 2;
  color: var(--text);
  background: #fff;
  border: 1px solid var(--line);
}

.chapter-content p {
  margin: 0 0 10px;
}

.chapter-content img {
  max-width: 100%;
  height: auto;
}

.chapter-content table {
  max-width: 100%;
  border-collapse: collapse;
}

.chapter-content iframe,
.chapter-content video {
  max-width: 100%;
}

.chapter-empty {
  padding: 30px 0;
  color: #999;
  text-align: center;
}

.chapter-menu {
  padding: 20px 15px;
  background: #fff;
  border: 1px solid var(--line);
}

.chapter-menu-head {
  padding-bottom: 12px;
  margin-bottom: 8px;
  border-bottom: 1px solid #eee;
}

.chapter-menu-title {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 400;
  color: var(--text);
}

.chapter-menu-sub {
  font-size: 12px;
  line-height: 1.6;
  color: var(--muted);
}

.chapter-menu-sub a {
  color: var(--brand-blue);
}

.chapter-menu-list {
  max-height: 520px;
  padding: 0;
  margin: 0;
  overflow: auto;
  list-style: none;
}

.chapter-menu-item {
  display: block;
  padding: 11px 20px 11px 10px;
  overflow: hidden;
  font-size: 14px;
  line-height: 1.5;
  color: #555;
  text-overflow: ellipsis;
  white-space: nowrap;
  border-bottom: 1px dashed var(--line);
}

.chapter-menu-item:hover {
  color: var(--brand-blue);
  background: #f6faff;
}

.chapter-menu-item.is-current {
  color: var(--brand-blue);
  background: #eef5fb;
}

.chapter-menu-item span {
  float: right;
  padding-left: 12px;
  color: var(--muted);
}

.chapter-menu-item.is-current span {
  color: var(--brand-blue);
}

.chapter-exercise {
  padding: 20px 15px;
  margin-top: 15px;
  font-size: 14px;
  line-height: 1.9;
  color: #333;
  background: #fff;
  border: 1px solid var(--line);
}

.chapter-exercise .title {
  margin: 0 0 12px;
  font-size: 17px;
  font-weight: 400;
}

.chapter-exercise .t {
  margin: 16px 0 8px;
  font-weight: bold;
}

.chapter-exercise input[type="radio"] {
  margin-right: 4px;
  vertical-align: middle;
}

.chapter-exercise-note {
  padding-top: 12px;
  margin-top: 14px;
  font-size: 12px;
  color: #999;
  border-top: 1px solid #eee;
}

@media (max-width: 1120px) {
  .chapter-layout {
    grid-template-columns: minmax(0, 1fr) 360px;
  }
}

@media (max-width: 900px) {
  .chapter-layout {
    grid-template-columns: 1fr;
  }

  .chapter-player {
    aspect-ratio: 16 / 9;
  }

  .chapter-content {
    padding: 26px 16px 16px;
    font-size: 15px;
    line-height: 1.9;
  }

  .chapter-menu-list {
    max-height: none;
  }

  .chapter-exercise {
    margin-bottom: 15px;
  }
}

@media (max-width: 640px) {
  .chapter-player audio {
    width: 92%;
  }

  .chapter-menu {
    padding: 16px 12px;
  }

  .chapter-menu-item {
    padding-left: 6px;
  }
}

/* ============================== Media player ============================== */

.media-modal {
  position: fixed;
  inset: 0;
  z-index: 1200;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.media-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.78);
}

.media-dialog {
  position: relative;
  z-index: 1;
  width: 900px;
  max-width: 100%;
  overflow: hidden;
  color: #fff;
  background: #111;
  border-radius: 6px;
  box-shadow: 0 18px 70px rgba(0, 0, 0, 0.5);
}

.media-head {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 18px;
  background: #1c1c1c;
}

.media-head h2 {
  flex: 1;
  margin: 0;
  overflow: hidden;
  font-size: 16px;
  font-weight: 400;
  color: #fff;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.media-close {
  flex: 0 0 32px;
  width: 32px;
  height: 32px;
  padding: 0;
  font-size: 24px;
  line-height: 28px;
  color: #bbb;
  background: transparent;
  border: 0;
}

.media-close:hover {
  color: #fff;
}

.media-stage {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 220px;
  padding: 16px;
  background: #000;
}

.media-stage video {
  display: block;
  width: 100%;
  max-height: 70vh;
  background: #000;
}

.media-stage audio {
  display: block;
  width: 100%;
  max-width: 640px;
}

.media-foot {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 12px 18px;
  font-size: 12px;
  color: #999;
  background: #1c1c1c;
}

.media-foot a {
  color: #8ec5ff;
}

.media-foot a:hover {
  color: #b9dcff;
}

.media-error {
  padding: 28px 18px;
  font-size: 14px;
  line-height: 1.9;
  color: #ddd;
  text-align: center;
}

.media-error strong {
  display: block;
  margin-bottom: 8px;
  font-size: 17px;
  color: #fff;
}

/* ============================== Modal / toast ============================== */

.archive-modal {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
}

.modal-dialog {
  position: relative;
  z-index: 1;
  width: 440px;
  max-width: 100%;
  padding: 28px 28px 24px;
  background: #fff;
  border-radius: 4px;
  box-shadow: 0 14px 50px rgba(0, 0, 0, 0.28);
}

.modal-dialog h2 {
  margin: 0 0 14px;
  font-size: 20px;
  font-weight: 500;
  color: var(--text);
}

.modal-dialog p {
  margin: 0 0 22px;
  font-size: 14px;
  line-height: 1.9;
  color: #666;
}

.modal-close {
  position: absolute;
  top: 8px;
  right: 10px;
  width: 32px;
  height: 32px;
  padding: 0;
  font-size: 24px;
  line-height: 30px;
  color: #999;
  background: transparent;
  border: 0;
}

.modal-close:hover {
  color: #333;
}

.modal-ok {
  display: block;
  width: 100%;
  padding: 9px 16px;
  font-size: 14px;
  color: #fff;
  background: var(--brand-blue);
  border: 0;
  border-radius: 3px;
}

.modal-ok:hover {
  background: #286090;
}

.modal-external {
  display: inline-block;
  margin-right: 10px;
  padding: 8px 16px;
  font-size: 14px;
  color: #fff !important;
  background: var(--brand-blue);
  border-radius: 3px;
}

.archive-toast {
  position: fixed;
  left: 50%;
  bottom: 32px;
  z-index: 1100;
  max-width: calc(100% - 32px);
  padding: 11px 18px;
  font-size: 14px;
  line-height: 1.5;
  color: #fff;
  text-align: center;
  background: rgba(30, 30, 30, 0.92);
  border-radius: 4px;
  transform: translate(-50%, 16px);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease, transform 0.25s ease;
}

.archive-toast.is-visible {
  opacity: 1;
  transform: translate(-50%, 0);
}

/* ============================== Media failure ============================== */

.is-media-missing {
  position: relative !important;
  background: #f1f1f1 !important;
  background-image: none !important;
}

.is-media-missing img {
  display: none !important;
}

.media-missing-label {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 8px;
  font-size: 12px;
  line-height: 1.4;
  color: #999;
  text-align: center;
  background: repeating-linear-gradient(
    45deg,
    #f3f3f3,
    #f3f3f3 8px,
    #ededed 8px,
    #ededed 16px
  );
}

.home-card.is-media-missing,
.card-cover.is-media-missing,
.course-cover.is-media-missing,
.artist-avatar.is-media-missing {
  display: inline-block;
}

/* 正文内的失效图片只显示行内提示，不覆盖整段正文。 */
.media-missing-inline {
  display: inline-block;
  margin: 4px 6px;
  padding: 3px 8px;
  font-size: 12px;
  line-height: 1.5;
  color: #999;
  vertical-align: middle;
  background: #f3f3f3;
  border: 1px dashed #ddd;
  border-radius: 3px;
}

/* ============================== Responsive ============================== */

@media (max-width: 1199px) {
  .home-cards {
    flex-wrap: wrap;
    gap: 28px;
  }

  .home-card {
    margin: 0;
  }
}

@media (max-width: 1120px) {
  .site-header,
  .hero,
  .page-banner {
    min-width: 0;
  }

  .header-inner {
    width: 100%;
    padding: 0 18px;
  }

  .brand {
    margin-right: 24px;
  }

  .main-nav a,
  .submit-link {
    padding: 0 7px;
    font-size: 15px;
  }

  .wrap {
    width: 100%;
    padding-right: 20px;
    padding-left: 20px;
  }

  .hero img {
    width: 100%;
  }

  .home-cards {
    padding: 0;
  }
}

@media (max-width: 900px) {
  .site-header {
    height: auto;
  }

  .header-inner {
    position: relative;
    height: auto;
    min-height: 58px;
    padding: 0 16px;
    flex-wrap: wrap;
  }

  .brand {
    height: 58px;
    margin: 0;
  }

  .brand img {
    width: 195px;
    height: 58px;
    object-fit: contain;
    object-position: left center;
  }

  .brand-text {
    height: 58px;
    font-size: 24px;
  }

  .nav-toggle {
    display: block;
  }

  .nav-panel {
    display: none;
    flex: 0 0 100%;
    flex-direction: column;
    align-items: stretch;
    width: calc(100% + 32px);
    margin: 0 -16px;
    padding: 4px 16px 14px;
    background: var(--header);
    border-top: 1px solid #4d4d4d;
  }

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

  .main-nav {
    display: block;
  }

  .main-nav a {
    padding: 0;
    font-size: 16px;
    line-height: 46px;
    border-bottom: 1px solid #4b4b4b;
  }

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

  .submit-link {
    margin: 8px 0 0;
    padding: 0;
    line-height: 42px;
    text-align: center;
    background: #2d2d2d;
  }

  .hero {
    height: auto;
    aspect-ratio: 1104 / 438;
    overflow: hidden;
    background: #f5f5f5;
  }

  .hero img {
    position: static;
    width: 100%;
    height: 100%;
    transform: none;
    object-fit: contain;
  }

  .page-banner {
    height: 220px;
    background-position: center;
  }

  .module-title {
    width: auto;
    margin-bottom: 26px;
    font-size: 30px;
  }

  .home-module {
    padding: 52px 16px 62px;
  }

  .home-cards {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 14px;
  }

  .home-card {
    flex: 0 0 calc(33.333% - 10px);
    width: calc(33.333% - 10px);
    height: auto;
    aspect-ratio: 1;
  }

  .home-card img {
    width: 100%;
    height: 100%;
  }

  .wrap {
    padding-right: 16px;
    padding-left: 16px;
  }

  .wrap.crumbs-wrap {
    padding-right: 20px;
    padding-left: 20px;
  }

  .cat {
    padding: 15px 15px 5px;
  }

  .cat .title {
    float: none;
    display: block;
    width: 100%;
    margin: 0 0 9px;
    text-align: left;
  }

  .cat .c {
    float: none;
    display: inline-block;
    margin: 0 12px 6px 0;
  }

  .course-item {
    padding: 16px;
  }

  .course-cover {
    float: none;
    width: 100%;
    height: auto;
    aspect-ratio: 400 / 254;
  }

  .course-cover img {
    height: 100%;
  }

  .course-info {
    float: none;
    width: 100%;
    padding: 14px 0 0;
  }

  .course-title {
    margin-bottom: 10px;
    font-size: 20px;
  }

  .course-author {
    font-size: 14px;
  }

  .course-brief {
    height: auto;
    max-height: 60px;
    -webkit-line-clamp: 3;
  }

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

  .broadcast-card {
    height: auto;
  }

  .card-cover {
    width: 100%;
    height: auto;
    aspect-ratio: 260 / 165;
  }

  .filter-row {
    gap: 6px;
  }

  .filter-row label {
    width: auto;
  }

  .filter-row input {
    flex: 1 1 140px;
    width: 140px;
  }

  .card-caption {
    display: none;
  }

  .detail-shell {
    padding: 16px;
  }

  .detail-title {
    margin-top: 18px;
    font-size: 22px;
  }

  .course-article,
  .article-card {
    padding: 16px;
  }

  .course-cover-large {
    float: none;
    width: 100%;
    height: auto;
    aspect-ratio: 400 / 254;
  }

  .course-intro-info {
    float: none;
    width: 100%;
    min-height: 0;
    padding: 18px 0 0;
  }

  .course-layout {
    grid-template-columns: 1fr;
  }

  .teacher-card {
    position: static;
  }

  .chapter-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
  }

  .chapter-card {
    padding: 8px;
  }

  .chapter-title {
    height: auto;
    min-height: 39px;
    margin-top: 8px;
    font-size: 13px;
    line-height: 1.5;
  }

  .chapter-play {
    width: 34px;
    height: 34px;
    margin: -17px 0 0 -17px;
  }

  .chapter-play::after {
    left: 12px;
    top: 9px;
    border-top-width: 6px;
    border-bottom-width: 6px;
    border-left-width: 9px;
  }

  .article-title {
    margin-top: 18px;
    font-size: 22px;
  }

  .article-meta {
    font-size: 14px;
  }

  .article-content {
    padding-top: 24px;
    font-size: 15px;
    line-height: 1.9;
  }

  .article-video {
    margin-bottom: 20px;
    border-radius: 4px;
  }

  .article-video video {
    max-height: 58vh;
  }

  .media-modal {
    padding: 12px;
  }

  .media-dialog {
    width: 100%;
  }

  .media-stage {
    min-height: 180px;
    padding: 8px;
  }

  .media-stage video {
    max-height: 52vh;
  }
}

@media (max-width: 640px) {
  .media-modal {
    padding: 0;
  }

  .media-dialog {
    width: 100%;
    max-height: 100vh;
    border-radius: 0;
  }

  .media-head {
    padding: 12px 14px;
  }

  .media-head h2 {
    font-size: 14px;
  }

  .media-foot {
    padding: 10px 14px;
    font-size: 11px;
  }
}

@media (max-width: 640px) {
  .brand img {
    width: 172px;
    height: 54px;
  }

  .header-inner {
    min-height: 54px;
  }

  .brand {
    height: 54px;
  }

  .home-cards {
    gap: 12px;
  }

  .home-card {
    flex-basis: calc(50% - 6px);
    width: calc(50% - 6px);
  }

  .home-card:last-child {
    margin-left: 0;
  }

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

  .page-banner {
    height: 170px;
  }

  .content-grid {
    grid-template-columns: 1fr;
  }

  .content-card {
    padding: 16px;
  }

  .card-cover {
    aspect-ratio: 16 / 9;
  }

  .card-title {
    font-size: 18px !important;
  }

  .filter-row {
    display: grid;
    grid-template-columns: auto 1fr;
    align-items: center;
  }

  .filter-row input {
    width: 100%;
    min-width: 0;
  }

  .filter-row .btn-primary {
    grid-column: 1 / -1;
    width: 100%;
    margin-top: 4px;
  }

  .filter-count {
    grid-column: 1 / -1;
    margin: 2px 0 0;
  }

  .cat .c {
    margin-right: 9px;
  }

  .course-title {
    font-size: 19px;
  }

  .course-meta {
    line-height: 32px;
  }

  .enter {
    width: 86px;
  }

  .pagination > li > a,
  .pagination > li > span {
    padding: 4px 8px;
    font-size: 12px;
  }

  .pagination > li:first-child,
  .pagination > li:last-child {
    display: none;
  }

  .pager-total {
    font-size: 12px;
    line-height: 1.6;
  }

  .site-footer {
    padding: 28px 16px 72px;
    font-size: 12px;
    line-height: 1.9;
    overflow-wrap: anywhere;
  }

  .footer-police img {
    width: 16px;
    height: 16px;
  }

  .detail-meta {
    font-size: 14px;
  }

  .archive-placeholder {
    padding: 38px 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}

/* ============================== Mobile quick navigation ============================== */
.mobile-tabbar {
  display: none;
}

@media (max-width: 900px) {
  body {
    padding-bottom: calc(60px + env(safe-area-inset-bottom));
  }

  .mobile-tabbar {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 100;
    display: flex;
    min-height: 60px;
    padding-bottom: env(safe-area-inset-bottom);
    background: rgba(255, 255, 255, 0.98);
    border-top: 1px solid #e4e4e4;
    box-shadow: 0 -4px 18px rgba(25, 40, 55, 0.08);
    backdrop-filter: blur(10px);
  }

  .mobile-tabbar a {
    display: flex;
    flex: 1 1 0;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2px;
    min-width: 0;
    padding: 6px 2px 4px;
    font-size: 11px;
    line-height: 1.2;
    color: #66707a;
  }

  .mobile-tabbar a:active {
    background: #f3f7fb;
  }

  .mobile-tabbar a[aria-current="page"] {
    color: var(--brand-blue);
    font-weight: bold;
  }

  .mobile-tabbar svg {
    width: 21px;
    height: 21px;
  }

  .mobile-tabbar-submit {
    color: #d97706 !important;
  }

  .back-to-top {
    bottom: calc(74px + env(safe-area-inset-bottom));
  }

  .site-footer {
    padding-bottom: 28px;
  }

  body.modal-open .mobile-tabbar {
    display: none;
  }
}

@media print {
  .mobile-tabbar {
    display: none !important;
  }
}

/* ============================== Mobile list experience ============================== */
.mobile-filter-toggle,
.mobile-course-filter-btn {
  display: none;
}

@media (max-width: 640px) {
  /* Works: horizontal categories, collapsible advanced filters, compact 2-column grid */
  .broadcasts-page .cat {
    padding: 10px 12px 12px;
  }

  .broadcasts-page .cat p {
    display: flex;
    flex-wrap: nowrap;
    gap: 4px;
    padding: 0 0 8px;
    overflow-x: auto;
    border-bottom: 0;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
  }

  .broadcasts-page .cat p::-webkit-scrollbar {
    display: none;
  }

  .broadcasts-page .cat .c {
    float: none;
    flex: 0 0 auto;
    margin-right: 2px;
    white-space: nowrap;
  }

  .mobile-filter-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    padding: 9px 10px;
    margin-top: 2px;
    font-size: 13px;
    color: #555;
    background: #f7f8fa;
    border: 0;
    border-top: 1px dashed var(--line);
    border-radius: 0 0 3px 3px;
  }

  .mobile-filter-toggle b {
    font-weight: 400;
    color: var(--brand-blue);
  }

  .broadcasts-page .filter-row {
    display: none;
    margin-top: 8px;
  }

  .broadcasts-page .filter-row.is-open {
    display: grid;
  }

  .broadcasts-page .content-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
    margin-top: 14px;
  }

  .broadcasts-page #broadcast-grid > .broadcast-card:nth-child(n + 13),
  .activities-page #activity-grid > .content-card:nth-child(n + 13) {
    display: none;
  }

  .broadcasts-page .content-card {
    padding: 10px;
    border-radius: 2px;
  }

  .broadcasts-page .card-cover {
    aspect-ratio: 4 / 3;
    border-radius: 2px;
  }

  .broadcasts-page .content-card .card-title {
    margin: 8px 0 4px;
    font-size: 14px;
    line-height: 1.4;
  }

  .broadcasts-page .item-tags {
    gap: 3px;
    margin: 4px 0 2px;
  }

  .broadcasts-page .item-tags a {
    padding: 0 6px;
    font-size: 11px;
    line-height: 18px;
    border-radius: 9px;
  }

  .broadcasts-page .item-tags a:not(:first-child) {
    display: none;
  }

  .broadcasts-page .card-meta,
  .broadcasts-page .card-brief {
    margin-top: 4px;
    font-size: 11px;
    line-height: 1.45;
  }

  .broadcasts-page .card-brief {
    margin-top: auto;
    padding-top: 4px;
  }

  /* Activities: shorter banner, horizontal tabs, compact horizontal cards */
  .activities-page .cat {
    padding: 10px 12px;
  }

  .activities-page .cat p {
    display: flex;
    flex-wrap: nowrap;
    gap: 4px;
    padding-bottom: 2px;
    overflow-x: auto;
    border-bottom: 0;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
  }

  .activities-page .cat p::-webkit-scrollbar {
    display: none;
  }

  .activities-page .cat .c {
    float: none;
    flex: 0 0 auto;
    margin-right: 2px;
    white-space: nowrap;
  }

  .activities-page .content-grid {
    grid-template-columns: 1fr;
    gap: 10px;
    margin-top: 14px;
  }

  .activities-page .content-card {
    display: grid;
    grid-template-columns: 112px minmax(0, 1fr);
    grid-template-rows: auto auto;
    column-gap: 12px;
    height: auto;
    padding: 10px;
  }

  .activities-page .card-cover {
    grid-row: 1 / span 2;
    width: 112px;
    height: 78px;
    aspect-ratio: auto;
  }

  .activities-page .content-card .card-title {
    margin: 0 0 6px;
    font-size: 15px;
    line-height: 1.45;
  }

  .activities-page .card-brief {
    margin: 0;
    padding-top: 0;
    font-size: 12px;
    line-height: 1.5;
  }

  /* Courses: filter hidden behind a compact button; compact horizontal course cards */
  .courses-page .mobile-course-filter-btn {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    padding: 12px 14px;
    margin: 10px 0 0;
    font-size: 14px;
    color: var(--text);
    text-align: left;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 2px;
  }

  .courses-page .mobile-course-filter-btn strong {
    color: var(--brand-blue);
    font-size: 13px;
    font-weight: 400;
  }

  .courses-page .cat {
    display: none;
    margin-top: 10px;
  }

  .courses-page.is-filter-open .cat {
    display: block;
  }

  .courses-page .course-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 12px;
    margin-top: 12px;
  }

  .courses-page .course-cover {
    float: none;
    flex: 0 0 112px;
    width: 112px;
    height: auto;
    aspect-ratio: 400 / 254;
  }

  .courses-page .course-cover img {
    height: 100%;
  }

  .courses-page .course-info {
    float: none;
    flex: 1 1 auto;
    width: auto;
    min-width: 0;
    padding-left: 0;
  }

  .courses-page .course-title {
    display: -webkit-box;
    margin: 0 0 5px;
    overflow: hidden;
    font-size: 16px;
    line-height: 1.35;
    white-space: normal;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
  }

  .courses-page .course-author {
    margin-bottom: 5px;
    font-size: 12px;
    line-height: 1.5;
    white-space: normal;
  }

  .courses-page .course-author img {
    flex-basis: 22px;
    width: 22px;
    height: 22px;
    margin-right: 7px;
  }

  .courses-page .course-brief {
    display: -webkit-box;
    height: auto;
    max-height: 38px;
    margin-bottom: 6px;
    overflow: hidden;
    font-size: 12px;
    line-height: 1.55;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
  }

  .courses-page .course-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    font-size: 12px;
    line-height: 1.5;
  }

  .courses-page .enter {
    float: none;
    flex: 0 0 auto;
    width: auto;
    height: 26px;
    padding: 0 10px;
    font-size: 12px;
    line-height: 26px;
    border-radius: 2px;
  }
}

/* ============================== Home layout refresh ============================== */
.home-cards {
  display: grid;
  width: 100%;
  max-width: 1024px;
  margin: 0 auto;
  padding: 0;
  gap: 24px;
}

.home-cards-courses {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.home-cards-dynamics {
  max-width: 800px;
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.home-card {
  width: 100%;
  max-width: none;
  height: auto;
  margin: 0;
  aspect-ratio: 1;
  overflow: hidden;
  border-radius: 6px;
  box-shadow: 0 2px 10px rgba(25, 40, 55, 0.08);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.home-card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.home-card:hover,
.home-card:focus {
  transform: translateY(-3px);
  box-shadow: 0 10px 24px rgba(25, 40, 55, 0.14);
}

.home-card:hover img,
.home-card:focus img {
  transform: scale(1.03);
  box-shadow: none;
}

.home-module {
  padding: 64px 0 76px;
}

@media (max-width: 900px) {
  .hero {
    background: #fff;
  }

  .hero img {
    object-fit: cover;
  }

  .home-module {
    padding: 38px 16px 48px;
  }

  .home-module .module-title {
    margin-bottom: 20px;
  }

  .home-cards {
    max-width: none;
    gap: 14px;
  }

  .home-cards-courses {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .home-cards-courses .home-card:nth-child(5) {
    grid-column: 1 / -1;
    justify-self: center;
    width: calc((100% - 42px) / 4);
  }

  .home-cards-dynamics {
    max-width: none;
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (max-width: 640px) {
  .home-main {
    padding: 0;
  }

  .hero {
    aspect-ratio: 1920 / 760;
    background: #fff;
  }

  .hero img {
    object-fit: cover;
    object-position: center;
  }

  .home-module {
    padding: 14px 14px 24px;
  }

  .home-module + .home-module {
    padding-top: 22px;
  }

  .home-module .module-title {
    display: none;
  }

  .home-cards,
  .home-cards-courses,
  .home-cards-dynamics {
    max-width: none;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
  }

  .home-cards-courses .home-card {
    grid-column: auto;
  }

  .home-cards-courses .home-card:last-child {
    grid-column: 1 / -1;
    justify-self: center;
    width: calc(50% - 5px);
  }

  .home-card {
    border-radius: 4px;
    box-shadow: 0 1px 6px rgba(25, 40, 55, 0.08);
  }

  .home-card:hover,
  .home-card:focus {
    transform: none;
    box-shadow: 0 1px 6px rgba(25, 40, 55, 0.08);
  }

  .crumbs {
    padding: 12px 0;
  }

}

/* ============================== Static works search ============================== */
.static-search-form {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px;
  margin: 0 0 16px;
  background: #fff;
  border: 1px solid var(--line);
}

.static-search-form select,
.static-search-form input {
  flex: 1 1 150px;
  min-width: 0;
  height: 34px;
  padding: 5px 10px;
  font-size: 14px;
  color: #555;
  background: #fff;
  border: 1px solid #ccc;
  border-radius: 3px;
  outline: 0;
}

.static-search-form select {
  flex: 0 1 130px;
}

.static-search-form .btn-primary {
  flex: 0 0 auto;
  height: 34px;
  padding: 5px 18px;
}

.static-search-form > a {
  flex: 0 0 auto;
  padding: 0 4px;
  font-size: 13px;
  color: var(--muted);
}

@media (max-width: 640px) {
  .static-search-form {
    display: grid;
    grid-template-columns: 1fr;
    gap: 8px;
    margin-bottom: 12px;
  }

  .static-search-form select,
  .static-search-form input,
  .static-search-form .btn-primary {
    width: 100%;
  }

  .static-search-form > a {
    justify-self: center;
    padding: 2px 0;
  }
}

/* ============================== Mobile home icon grid ============================== */
.mobile-home-icons {
  display: none;
}

@media (max-width: 640px) {
  .mobile-home-icons {
    display: block;
    padding: 10px 12px 18px;
    background: #fff;
  }

  .mobile-icon-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
  }

  .mobile-icon {
    display: block;
    aspect-ratio: 340 / 200;
    overflow: hidden;
    background: #f5f5f5;
    border-radius: 4px;
  }

  .mobile-icon img {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: cover;
  }

  .mobile-icon:nth-child(9) {
    grid-column: 1;
    width: auto;
    justify-self: stretch;
  }

  .home-main > .home-module {
    display: none;
  }
}

/* ============================== 2026 细节优化 ============================== */
/* 只调整标题、分类、卡片、筛选、按钮与详情页的呈现，不改变页面结构、链接和归档信息。 */

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

.site-footer {
  margin-top: auto;
}

/* 首页两个栏目标题：去掉两侧短横，改为轻量标题 + 短线 */
.home-module .module-title {
  position: relative;
  width: auto;
  height: auto;
  margin: 0 auto 34px;
  padding-bottom: 14px;
  font-size: 30px;
  font-weight: 300;
  line-height: 1.35;
  color: #333;
  letter-spacing: 0.14em;
}

.home-module .module-title::after {
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 34px;
  height: 2px;
  content: "";
  background: var(--brand-cyan);
  border-radius: 2px;
  transform: translateX(-50%);
}

/* 分类区域：降低色块和边框的存在感 */
.cat {
  padding: 18px 20px;
  background: #fff;
  border: 1px solid #e9ecf0;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(32, 54, 74, 0.03);
}

.cat p {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px 2px;
  padding: 0 0 10px;
  border-bottom: 1px solid #f1f3f5;
}

.cat p + p {
  padding-top: 10px;
}

.cat p:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.cat .title {
  float: none;
  flex: 0 0 96px;
  width: 96px;
  padding: 2px 0 2px 10px;
  margin: 0 8px 0 0;
  font-size: 14px;
  font-weight: 600;
  line-height: 1.6;
  color: #333;
  text-align: left;
  background: transparent;
  border-left: 3px solid var(--brand-cyan);
  border-radius: 0;
}

.cat .title.here,
.cat .title.is-active {
  color: var(--brand-cyan);
  background: transparent;
}

.cat .c {
  float: none;
  display: inline-flex;
  align-items: center;
  padding: 4px 8px;
  margin: 0 2px;
  font-size: 13px;
  line-height: 1.6;
  color: #666;
  background: transparent;
  border-radius: 4px;
  transition: color 0.18s ease, background-color 0.18s ease;
}

.cat .c:hover {
  color: var(--brand-cyan);
  background: #f2f9fd;
}

.cat .c.here,
.cat .c.is-active {
  color: var(--brand-cyan);
  background: #eef7fc;
}

/* 课程分类：子分类改为轻量文字链接，不再使用一排灰色块 */
.courses-page .cat {
  padding: 18px 22px;
}

.courses-page .cat p {
  gap: 0;
}

.courses-page .cat .title {
  flex-basis: 88px;
  width: 88px;
}

.courses-page .cat .c {
  margin: 0 16px 0 0;
  padding: 3px 0;
  color: #666;
  border-bottom: 1px solid transparent;
  border-radius: 0;
}

.courses-page .cat .c:hover {
  color: var(--brand-cyan);
  background: transparent;
  border-bottom-color: #bfe3f5;
}

.courses-page .cat .c.here,
.courses-page .cat .c.is-active {
  color: var(--brand-cyan);
  background: transparent;
  border-bottom-color: var(--brand-cyan);
}

/* 社团活动 Tab：轻量分段式，而不是硬色块 */
.activities-page .cat {
  padding: 0 0 4px;
  background: transparent;
  border: 0;
  box-shadow: none;
}

.activities-page .cat p {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 3px;
  padding: 4px;
  background: #f3f6f8;
  border: 1px solid #e9edf1;
  border-radius: 8px;
}

.activities-page .cat .c {
  padding: 7px 15px;
  margin: 0;
  font-size: 13px;
  color: #666;
  border-radius: 6px;
}

.activities-page .cat .c:hover {
  color: var(--brand-cyan);
  background: rgba(255, 255, 255, 0.7);
}

.activities-page .cat .c.here,
.activities-page .cat .c.is-active {
  color: #2f7fa8;
  background: #fff;
  box-shadow: 0 1px 4px rgba(32, 54, 74, 0.08);
}

/* 作品展播分类：软胶囊，保留横向滚动能力 */
.broadcasts-page .cat .c {
  padding: 5px 10px;
  border-radius: 999px;
}

.broadcasts-page .cat .c.here,
.broadcasts-page .cat .c.is-active {
  color: #2f7fa8;
  background: #eaf5fb;
}

/* 筛选输入与按钮 */
.filter-row {
  gap: 8px;
  padding-top: 12px;
  margin-top: 10px;
  border-top: 1px solid #f1f3f5;
}

.filter-row label {
  font-size: 12px;
  color: #777;
}

.filter-row input,
.static-search-form input,
.static-search-form select {
  height: 34px;
  padding: 5px 10px;
  font-size: 13px;
  color: #444;
  background: #fafbfc;
  border: 1px solid #e3e7eb;
  border-radius: 6px;
  outline: 0;
  transition: border-color 0.18s ease, box-shadow 0.18s ease, background-color 0.18s ease;
}

.filter-row input:focus,
.static-search-form input:focus,
.static-search-form select:focus {
  background: #fff;
  border-color: #9fd4ef;
  box-shadow: 0 0 0 3px rgba(62, 175, 224, 0.1);
}

.btn-primary {
  height: 34px;
  padding: 0 16px;
  font-size: 13px;
  color: #fff;
  background: var(--brand-cyan);
  border: 1px solid var(--brand-cyan);
  border-radius: 6px;
  transition: background-color 0.18s ease, border-color 0.18s ease;
}

.btn-primary:hover {
  color: #fff;
  background: #2f9ac8;
  border-color: #2f9ac8;
}

.filter-count {
  font-size: 12px;
  color: #8a8f96;
}

.static-search-form {
  padding: 14px;
  border: 1px solid #e9ecf0;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(32, 54, 74, 0.03);
}

/* 课程列表：图文关系更清楚，进入按钮改成轻量软按钮 */
.course-item {
  display: flex;
  align-items: stretch;
  gap: 0;
  padding: 20px 22px;
  margin-top: 18px;
  overflow: hidden;
  background: #fff;
  border: 1px solid #e9ecf0;
  border-radius: 8px;
  box-shadow: 0 1px 2px rgba(32, 54, 74, 0.03);
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.course-item:hover,
.course-item:focus {
  border-color: #cfe6f4;
  box-shadow: 0 8px 22px rgba(51, 122, 183, 0.08);
  transform: translateY(-1px);
}

.course-cover {
  float: none;
  flex: 0 0 250px;
  align-self: flex-start;
  width: 250px;
  height: auto;
  min-height: 0;
  aspect-ratio: 400 / 254;
  overflow: hidden;
  background: #f5f7f9;
  border-radius: 5px;
}

.course-cover img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.course-info {
  float: none;
  display: flex;
  flex: 1 1 auto;
  flex-direction: column;
  width: auto;
  min-width: 0;
  padding: 2px 0 2px 26px;
}

.course-title {
  margin: 0 0 9px;
  overflow: visible;
  font-size: 22px;
  font-weight: 400;
  line-height: 1.35;
  color: #2b2b2b;
  white-space: normal;
  text-overflow: clip;
}

.course-author {
  padding: 0;
  margin: 0 0 9px;
  font-size: 13px;
  color: #888;
}

.course-author img {
  flex-basis: 26px;
  width: 26px;
  height: 26px;
  margin-right: 8px;
}

.course-brief {
  max-height: 52px;
  margin: 0 0 12px;
  font-size: 13px;
  line-height: 1.8;
  color: #777;
  -webkit-line-clamp: 2;
}

.course-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-top: 10px;
  margin: auto 0 0;
  font-size: 12px;
  line-height: 1.6;
  color: #999;
  border-top: 1px solid #f1f3f5;
}

.enter {
  float: none;
  display: inline-flex;
  flex: 0 0 auto;
  align-items: center;
  justify-content: center;
  width: auto;
  height: 30px;
  padding: 0 13px;
  font-size: 12px;
  font-weight: 400;
  line-height: 28px;
  color: var(--brand-cyan) !important;
  white-space: nowrap;
  background: #f2f9fd;
  border: 1px solid #cfe9f6;
  border-radius: 999px;
  transition: color 0.18s ease, background-color 0.18s ease, border-color 0.18s ease;
}

.enter::after {
  margin-left: 5px;
  font-size: 14px;
  line-height: 1;
  content: "›";
}

.course-item:hover .enter,
.course-item:focus .enter {
  color: #fff !important;
  background: var(--brand-cyan);
  border-color: var(--brand-cyan);
}

/* 社团 / 作品卡片：留白更均匀，标签和说明更轻 */
.content-grid {
  gap: 18px;
  margin-top: 22px;
}

.content-card {
  padding: 18px;
  background: #fff;
  border: 1px solid #e9ecf0;
  border-radius: 8px;
  box-shadow: 0 1px 2px rgba(32, 54, 74, 0.03);
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.content-card:hover,
.content-card:focus-within {
  border-color: #cfe6f4;
  box-shadow: 0 8px 22px rgba(51, 122, 183, 0.08);
  transform: translateY(-2px);
}

.card-cover {
  border-radius: 5px;
  background: #f4f6f8;
}

.card-caption {
  inset: auto 0 0;
  align-items: flex-end;
  justify-content: flex-start;
  padding: 26px 12px 10px;
  text-align: left;
  background: linear-gradient(to top, rgba(24, 34, 44, 0.58), rgba(24, 34, 44, 0));
  opacity: 0;
  transition: opacity 0.22s ease;
}

.card-caption strong {
  margin: 0;
  font-size: 12px;
  font-weight: 400;
}

.card-caption span {
  display: none;
}

.content-card:hover .card-caption,
.content-card:focus-within .card-caption {
  opacity: 1;
}

.content-card .card-title {
  margin: 11px 0 7px;
  font-size: 17px;
  font-weight: 500;
  line-height: 1.5;
  color: #2b2b2b;
}

.content-card .card-title a:hover {
  color: var(--brand-cyan);
}

.item-tags {
  gap: 5px;
  margin: 6px 0 4px;
}

.item-tags a {
  padding: 1px 8px;
  font-size: 11px;
  line-height: 20px;
  color: #777;
  background: #f4f6f8;
  border-radius: 999px;
}

.item-tags a:first-child {
  color: #2f7fa8;
  background: #eaf5fb;
}

.item-tags a:last-child {
  color: #777;
  background: #f4f6f8;
}

.item-tags a:hover {
  color: var(--brand-cyan);
  filter: none;
}

.card-meta,
.card-brief {
  font-size: 12px;
  line-height: 1.65;
  color: #8a8f96;
}

.content-card .card-brief:last-child {
  margin-top: auto;
}

/* 分页：轻量胶囊式 */
.pagination {
  gap: 6px;
}

.pagination > li > a,
.pagination > li > span {
  padding: 6px 12px;
  margin: 0;
  font-size: 13px;
  line-height: 1.5;
  color: #666;
  background: #fff;
  border: 1px solid #e5e9ed;
  border-radius: 6px;
}

.pagination > li:first-child > a,
.pagination > li:last-child > a {
  border-radius: 6px;
}

.pagination > li.active > span {
  color: #2f7fa8;
  background: #eaf5fb;
  border-color: #cfe9f6;
}

.pagination a:hover {
  color: #2f7fa8;
  background: #f4fafd;
  border-color: #cfe9f6;
}

.pagination .is-ellipsis {
  background: transparent;
  border-color: transparent;
}

.pager-total {
  margin-top: 10px;
  font-size: 12px;
  color: #999;
}

/* 课程详情、活动详情、作品详情：统一为轻量内容卡片 */
.course-article,
.article-card,
.detail-shell {
  padding: 24px;
  background: #fff;
  border: 1px solid #e9ecf0;
  border-radius: 8px;
  box-shadow: 0 1px 2px rgba(32, 54, 74, 0.03);
}

.course-intro {
  align-items: start;
}

.course-cover-large {
  border-radius: 5px;
  background: #f4f6f8;
}

.course-intro-info h1,
.article-title,
.detail-title {
  font-size: 24px;
  font-weight: 400;
  line-height: 1.45;
  color: #2b2b2b;
}

.course-intro-label {
  color: #888;
  font-weight: 400;
}

.course-intro-brief,
.detail-content,
.article-content {
  color: #555;
}

.course-statline,
.article-meta,
.detail-meta {
  font-size: 13px;
  color: #888;
}

.course-layout {
  gap: 18px;
  margin-top: 20px;
}

.course-catalog,
.teacher-card {
  padding: 20px;
  background: #fff;
  border: 1px solid #e9ecf0;
  border-radius: 8px;
  box-shadow: 0 1px 2px rgba(32, 54, 74, 0.03);
}

.catalog-head {
  padding-bottom: 12px;
  margin-bottom: 14px;
  border-bottom: 1px solid #f1f3f5;
}

.catalog-title {
  font-size: 19px;
  font-weight: 500;
}

.catalog-note {
  padding: 9px 12px;
  color: #777;
  background: #f8fafb;
  border-left: 3px solid #d7e8f2;
  border-radius: 0 5px 5px 0;
}

.chapter-card {
  padding: 9px;
  background: #fafbfc;
  border: 1px solid #f0f2f4;
  border-radius: 5px;
}

.chapter-card:hover,
.chapter-card:focus {
  background: #f4f9fc;
  border-color: #dcecf5;
  box-shadow: 0 3px 10px rgba(51, 122, 183, 0.07);
}

.chapter-title {
  font-weight: 500;
}

.back-link {
  display: inline-flex;
  align-items: center;
  height: 32px;
  padding: 0 14px;
  font-size: 13px;
  color: #fff !important;
  background: var(--brand-cyan);
  border-radius: 6px;
}

.back-link:hover {
  background: #2f9ac8;
}

/* 手机端：保留原有紧凑布局，只柔化间距、圆角和按钮 */
@media (max-width: 900px) {
  .home-module .module-title {
    margin-bottom: 18px;
    font-size: 26px;
  }

  .content-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
  }

  .activities-page .cat p {
    display: flex;
    flex-wrap: nowrap;
    gap: 3px;
    overflow-x: auto;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
  }

  .activities-page .cat p::-webkit-scrollbar,
  .broadcasts-page .cat p::-webkit-scrollbar {
    display: none;
  }

  .broadcasts-page .cat p {
    display: flex;
    flex-wrap: nowrap;
    gap: 4px;
    overflow-x: auto;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
  }

  .broadcasts-page .cat .c,
  .activities-page .cat .c {
    flex: 0 0 auto;
    white-space: nowrap;
  }
}

@media (max-width: 640px) {
  .home-module .module-title {
    margin-bottom: 14px;
    font-size: 24px;
  }

  .cat {
    padding: 12px;
    border-radius: 7px;
  }

  .courses-page .cat {
    padding: 14px;
  }

  .courses-page .cat .title {
    flex-basis: 76px;
    width: 76px;
    font-size: 13px;
  }

  .courses-page .cat .c {
    margin-right: 12px;
    font-size: 12px;
  }

  .activities-page .cat {
    padding: 0 0 2px;
  }

  .activities-page .cat p {
    padding: 3px;
  }

  .activities-page .cat .c {
    padding: 6px 13px;
    font-size: 12px;
  }

  .broadcasts-page .cat {
    padding: 12px;
  }

  .broadcasts-page .cat p {
    padding-bottom: 7px;
  }

  .filter-row {
    gap: 7px;
    padding-top: 10px;
    margin-top: 8px;
  }

  .filter-row input,
  .static-search-form input,
  .static-search-form select,
  .btn-primary {
    height: 34px;
  }

  .mobile-filter-toggle {
    padding: 9px 12px;
    margin-top: 8px;
    font-size: 13px;
    color: #666;
    background: #f8fafb;
    border: 1px solid #e9edf1;
    border-radius: 6px;
  }

  .mobile-filter-toggle b {
    font-weight: 400;
    color: var(--brand-cyan);
  }

  .courses-page .mobile-course-filter-btn {
    padding: 10px 12px;
    margin-top: 8px;
    font-size: 13px;
    color: #555;
    background: #fff;
    border: 1px solid #e9edf1;
    border-radius: 6px;
  }

  .courses-page .mobile-course-filter-btn strong {
    font-size: 12px;
    font-weight: 400;
    color: var(--brand-cyan);
  }

  .course-item,
  .courses-page .course-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 12px;
    margin-top: 12px;
    border-radius: 7px;
  }

  .courses-page .course-cover {
    flex: 0 0 112px;
    width: 112px;
    height: auto;
    aspect-ratio: 400 / 254;
    border-radius: 4px;
  }

  .courses-page .course-info {
    padding: 0;
  }

  .courses-page .course-title {
    margin-bottom: 5px;
    font-size: 16px;
    line-height: 1.35;
  }

  .courses-page .course-author {
    margin-bottom: 5px;
    font-size: 12px;
  }

  .courses-page .course-brief {
    max-height: 38px;
    margin-bottom: 6px;
    font-size: 12px;
    line-height: 1.55;
    -webkit-line-clamp: 2;
  }

  .courses-page .course-meta {
    padding-top: 0;
    margin-top: 0;
    border-top: 0;
  }

  .courses-page .enter,
  .enter {
    height: 26px;
    padding: 0 10px;
    font-size: 11px;
    line-height: 24px;
  }

  .enter::after {
    margin-left: 3px;
    font-size: 12px;
  }

  .content-grid {
    gap: 12px;
    margin-top: 16px;
  }

  .content-card {
    padding: 12px;
    border-radius: 7px;
  }

  .broadcasts-page .content-card {
    padding: 10px;
    border-radius: 7px;
  }

  .broadcasts-page .card-cover {
    border-radius: 4px;
  }

  .broadcasts-page .content-card .card-title {
    margin: 8px 0 4px;
    font-size: 14px;
  }

  .broadcasts-page .item-tags {
    gap: 3px;
    margin: 4px 0 2px;
  }

  .broadcasts-page .item-tags a {
    padding: 0 6px;
    font-size: 10px;
    line-height: 18px;
  }

  .broadcasts-page .card-meta,
  .broadcasts-page .card-brief {
    font-size: 11px;
    line-height: 1.45;
  }

  .activities-page .content-card {
    display: grid;
    grid-template-columns: 112px minmax(0, 1fr);
    grid-template-rows: auto auto;
    column-gap: 12px;
    align-items: start;
    padding: 10px;
    border-radius: 7px;
  }

  .activities-page .card-cover {
    grid-row: 1 / span 2;
    width: 112px;
    height: 78px;
    border-radius: 4px;
  }

  .activities-page .content-card .card-title {
    margin: 0 0 6px;
    font-size: 15px;
  }

  .activities-page .card-brief {
    font-size: 12px;
    line-height: 1.5;
  }

  .pagination {
    gap: 4px;
  }

  .pagination > li > a,
  .pagination > li > span {
    padding: 4px 8px;
    font-size: 12px;
    border-radius: 5px;
  }

  .pager-total {
    font-size: 12px;
  }

  .course-article,
  .article-card,
  .detail-shell {
    padding: 16px;
    border-radius: 7px;
  }

  .course-intro-info h1,
  .article-title,
  .detail-title {
    font-size: 22px;
  }

  .course-catalog,
  .teacher-card {
    padding: 16px;
    border-radius: 7px;
  }

  .chapter-card {
    border-radius: 4px;
  }

  .back-link {
    height: 30px;
    padding: 0 12px;
    font-size: 12px;
    border-radius: 5px;
  }
}

/* ============================== 章节习题作答 ============================== */
.chapter-exercise input[type="radio"] {
  width: 15px;
  height: 15px;
  cursor: pointer;
  accent-color: var(--brand-cyan);
}

.chapter-exercise input[value="1"]:checked {
  accent-color: #2e7d32;
}

.chapter-exercise input[value="0"]:checked {
  accent-color: #c62828;
}

.exercise-feedback {
  display: inline-block;
  padding: 3px 10px;
  margin: 8px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: #888;
  background: #f7f8fa;
  border-radius: 4px;
}

.exercise-feedback.is-correct {
  color: #2e7d32;
  background: #edf7ee;
}

.exercise-feedback.is-wrong {
  color: #c62828;
  background: #fceeee;
}