:root {
  --bg: #050505;
  --bg-soft: #0a0d13;
  --surface: #0f141e;
  --surface-2: #141b28;
  --line: #2c3548;
  --text: #f4f6fb;
  --text-soft: #b8c1d3;
  --green: #40dc80;
  --orange: #cb5d2f;
  --link: #8eb4ff;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  font-family: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
  color: var(--text);
  background: radial-gradient(circle at 18% -10%, #1d263f 0%, #090b10 38%, #050505 100%);
}

html {
  overflow-y: scroll;
  scrollbar-gutter: stable;
}

body {
  scrollbar-width: thin;
  scrollbar-color: #4f648b rgba(8, 12, 19, 0.72);
}

body::-webkit-scrollbar {
  width: 8px;
}

body::-webkit-scrollbar-track {
  background: rgba(8, 12, 19, 0.72);
}

body::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, #5f79a7, #465c82);
  border-radius: 999px;
}

body::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(180deg, #7592c7, #566e98);
}

a {
  color: inherit;
  text-decoration: none;
}

.site-wrap {
  min-height: 100vh;
}

.container {
  width: min(1160px, 92vw);
  margin: 0 auto;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  border-bottom: 1px solid #20293a;
  background: rgba(5, 5, 8, 0.84);
  backdrop-filter: blur(8px);
}

.topbar-inner {
  min-height: 70px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
}

.brand {
  font-size: 24px;
  font-weight: 700;
  color: #ffffff;
  text-shadow: 0 0 10px rgba(64, 220, 128, 0.35);
  letter-spacing: 0.4px;
}

.brand span {
  margin-left: 8px;
  font-size: 17px;
  font-weight: 600;
  color: #f0f4ff;
}

.nav {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.nav a {
  padding: 9px 14px;
  border-radius: 999px;
  border: 1px solid transparent;
  color: #d1d9ea;
  font-size: 14px;
  transition: all 180ms ease;
}

.nav a:hover {
  border-color: #394764;
  background: rgba(18, 26, 42, 0.6);
  color: #ffffff;
}

.nav a.active {
  border-color: #435983;
  background: rgba(27, 42, 70, 0.72);
  color: #ffffff;
}

.page-main {
  padding: 28px 0 54px;
}

.page-hero {
  position: relative;
  overflow: hidden;
  margin-bottom: 18px;
  border-radius: 20px;
  border: 1px solid #2c3649;
  background-image: linear-gradient(116deg, rgba(0, 0, 0, 0.65), rgba(0, 0, 0, 0.74)),
    url('https://images.unsplash.com/photo-1486325212027-8081e485255e?auto=format&fit=crop&w=1800&q=80');
  background-size: cover;
  background-position: center;
  box-shadow: 0 16px 32px rgba(0, 0, 0, 0.35);
  padding: 24px 28px 30px;
}

.page-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.resources-tone::before {
  background: radial-gradient(circle at 16% 22%, rgba(64, 220, 128, 0.45), rgba(64, 220, 128, 0) 32%);
}

.classroom-tone::before {
  background: radial-gradient(circle at 20% 24%, rgba(230, 120, 47, 0.43), rgba(230, 120, 47, 0) 34%);
}

.updates-tone::before {
  background: radial-gradient(circle at 18% 22%, rgba(86, 98, 135, 0.52), rgba(86, 98, 135, 0) 34%);
}

.page-hero > * {
  position: relative;
  z-index: 1;
}

.breadcrumb {
  margin: 0;
  color: #d3dcf0;
  font-size: 13px;
}

.breadcrumb a {
  color: #f3f6ff;
}

.page-hero h1 {
  margin: 10px 0 8px;
  font-size: clamp(32px, 4.2vw, 52px);
  line-height: 1.12;
  letter-spacing: 0.3px;
}

.hero-text {
  margin: 0;
  color: var(--orange);
  font-size: clamp(14px, 1.6vw, 22px);
  font-weight: 700;
  line-height: 1.65;
  max-width: 820px;
}

.hero-meta {
  margin-top: 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.meta-pill {
  height: 34px;
  padding: 0 14px;
  border-radius: 999px;
  border: 1px solid #354563;
  background: rgba(12, 20, 33, 0.8);
  color: #dbe5fb;
  display: inline-flex;
  align-items: center;
  font-size: 13px;
}

.panel,
.featured-course,
.course-card,
.feed-item,
.side-card {
  background: linear-gradient(160deg, rgba(16, 21, 32, 0.94), rgba(10, 14, 22, 0.92));
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: 0 14px 28px rgba(0, 0, 0, 0.28);
}

.panel {
  padding: 16px;
}

.panel-compact {
  margin-bottom: 14px;
}

.panel-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 14px;
}

.filter-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.pill {
  border: 1px solid #313d54;
  background: rgba(14, 20, 32, 0.8);
  color: #cbd5ea;
  border-radius: 999px;
  font-size: 13px;
  padding: 7px 12px;
}

.pill.active {
  background: rgba(42, 63, 106, 0.85);
  border-color: #5872aa;
  color: #ffffff;
}

.search-box {
  display: inline-flex;
}

.search-box input {
  width: min(280px, 78vw);
  height: 36px;
  border-radius: 10px;
  border: 1px solid #324159;
  padding: 0 12px;
  color: #ecf2ff;
  background: rgba(9, 13, 21, 0.9);
  font-size: 14px;
  outline: none;
}

.search-box input::placeholder {
  color: #8694ad;
}

.search-box input:focus {
  border-color: #5b75b5;
  box-shadow: 0 0 0 3px rgba(85, 113, 179, 0.24);
}

.panel-meta {
  margin-bottom: 14px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.status-text {
  margin: 0;
  color: var(--text-soft);
  font-size: 14px;
}

.sort-box {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text-soft);
  font-size: 13px;
}

.sort-box select {
  height: 36px;
  border-radius: 10px;
  border: 1px solid #324159;
  padding: 0 12px;
  color: #ecf2ff;
  background: rgba(9, 13, 21, 0.9);
  font-size: 14px;
  outline: none;
}

.sort-box select:focus {
  border-color: #5b75b5;
  box-shadow: 0 0 0 3px rgba(85, 113, 179, 0.24);
}

.table-wrap {
  border: 1px solid #2a3548;
  border-radius: 12px;
  overflow: auto;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 760px;
}

.data-table th,
.data-table td {
  padding: 14px 16px;
  border-bottom: 1px solid #263143;
  font-size: 14px;
  text-align: left;
}

.data-table th {
  background: #131c2a;
  color: #d8e1f2;
  font-weight: 600;
}

.data-table tbody tr:hover {
  background: rgba(20, 30, 46, 0.62);
}

.data-table tr:last-child td {
  border-bottom: 0;
}

.badge {
  min-width: 54px;
  height: 26px;
  padding: 0 10px;
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 700;
}

.b-pdf {
  color: #ff9b9b;
  background: rgba(181, 71, 71, 0.22);
}

.b-ppt {
  color: #ffc38d;
  background: rgba(182, 97, 34, 0.21);
}

.b-word {
  color: #9ab9ff;
  background: rgba(47, 98, 199, 0.23);
}

.b-image {
  color: #95e3ac;
  background: rgba(31, 138, 82, 0.22);
}

.b-video {
  color: #d7b2ff;
  background: rgba(122, 67, 181, 0.25);
}

.action-link {
  color: var(--link);
  font-weight: 600;
}

.action-link:hover {
  color: #c0d7ff;
}

.detail-link {
  color: #ffffff;
}

.detail-link:hover {
  color: #c0d7ff;
}

.detail-link-block {
  text-decoration: none;
}

.empty-state {
  padding: 28px 18px;
  border: 1px dashed #36445f;
  border-radius: 12px;
  background: rgba(13, 19, 31, 0.72);
  text-align: center;
}

.empty-state p {
  margin: 0;
  color: var(--text-soft);
}

.featured-course {
  display: grid;
  grid-template-columns: 320px 1fr;
  overflow: hidden;
  margin-bottom: 14px;
}

.featured-cover {
  background: linear-gradient(145deg, #243564, #283a6c 56%, #4f628e 100%);
  background-size: cover;
  background-position: center;
  min-height: 220px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.featured-cover.has-cover {
  background-size: cover;
  background-position: center;
}

.featured-link:hover {
  filter: brightness(1.08);
}

.featured-cover span {
  font-size: 22px;
  font-weight: 700;
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.36);
  padding: 8px 16px;
  border-radius: 999px;
}

.featured-body {
  padding: 20px 22px;
}

.featured-label {
  margin: 0;
  color: #93b4ff;
  font-weight: 600;
  font-size: 13px;
}

.featured-body h2 {
  margin: 8px 0 10px;
  font-size: 30px;
  line-height: 1.2;
  color: #ffffff;
}

.featured-body p {
  margin: 0;
  color: var(--text-soft);
  line-height: 1.75;
}

.card-meta {
  margin-top: 14px;
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: center;
  font-size: 13px;
  color: #afbbd2;
}

.meta-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

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

.course-thumb {
  height: 118px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, #21325a, #2f4479);
  background-size: cover;
  background-position: center;
  color: #ffffff;
  font-weight: 700;
}

.course-thumb.has-cover {
  background-size: cover;
  background-position: center;
}

.course-thumb span {
  padding: 8px 14px;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.3);
  background: rgba(9, 13, 21, 0.22);
}

.course-body {
  padding: 14px 16px;
}

.course-body h3 {
  margin: 0;
  font-size: 18px;
  color: #ffffff;
}

.course-body p {
  margin: 8px 0 0;
  color: var(--text-soft);
  line-height: 1.7;
}

.course-tags {
  margin-top: 12px;
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.course-tags span {
  height: 28px;
  padding: 0 10px;
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  border: 1px solid #36455f;
  background: rgba(19, 28, 42, 0.74);
  color: #dce7ff;
  font-size: 12px;
}

.feed-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 14px;
}

.feed-stream,
.side-panel {
  display: grid;
  gap: 12px;
}

.feed-item {
  padding: 16px;
}

.feed-top {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
}

.avatar {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: linear-gradient(145deg, #2f4479, #4e6597);
  color: #ffffff;
  font-weight: 700;
}

.feed-top h3 {
  margin: 0 0 4px;
  font-size: 16px;
  color: #ffffff;
}

.feed-author {
  margin: 0 0 4px;
  color: #dce7ff;
  font-size: 13px;
}

.feed-top time {
  color: #adbad1;
  font-size: 12px;
}

.feed-item p {
  margin: 0;
  color: #d5deef;
  line-height: 1.8;
}

.feed-content {
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  overflow: hidden;
}

.feed-content.is-expanded {
  display: block;
}

.feed-tags {
  margin-top: 12px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.feed-tags span {
  height: 28px;
  padding: 0 10px;
  border-radius: 999px;
  border: 1px solid #3d4f74;
  color: #dbe6ff;
  background: rgba(20, 31, 52, 0.72);
  font-size: 12px;
  display: inline-flex;
  align-items: center;
}

.feed-actions {
  margin-top: 14px;
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.ghost-btn {
  height: 32px;
  padding: 0 12px;
  border-radius: 999px;
  border: 1px solid #34435e;
  background: rgba(14, 20, 32, 0.8);
  color: #d5deef;
  font-size: 13px;
  cursor: pointer;
}

.ghost-btn:hover {
  border-color: #516992;
  color: #ffffff;
}

.ghost-btn.is-active,
.ghost-btn[aria-pressed='true'] {
  background: rgba(42, 63, 106, 0.85);
  border-color: #5f7bbb;
  color: #ffffff;
}

.ghost-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.side-card {
  padding: 16px;
}

.side-card h4 {
  margin: 0 0 10px;
  font-size: 16px;
  color: #ffffff;
}

.side-card ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.side-card li {
  color: #cad5ec;
  font-size: 14px;
  line-height: 1.6;
}

.detail-hero {
  margin-bottom: 14px;
}

.detail-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 14px;
}

.detail-main {
  min-width: 0;
}

.detail-video {
  margin-bottom: 18px;
}

.detail-video video {
  width: 100%;
  display: block;
  border-radius: 12px;
  background: #000;
}

.detail-body h2,
.detail-body h3 {
  color: #ffffff;
}

.detail-body h2 {
  margin: 0 0 12px;
  font-size: 24px;
}

.detail-body h3 {
  margin: 22px 0 12px;
  font-size: 18px;
}

.detail-body p {
  margin: 0 0 14px;
  color: #d5deef;
  line-height: 1.9;
}

.detail-list {
  margin: 0;
  padding-left: 20px;
  color: #d5deef;
  line-height: 1.9;
}

.detail-points li::marker {
  color: #86a8ff;
}

.detail-side {
  display: grid;
  gap: 12px;
  align-content: start;
}

.detail-actions {
  display: grid;
  gap: 10px;
}

.related-list {
  display: grid;
  gap: 10px;
}

.related-card {
  display: block;
  padding: 12px 14px;
  border-radius: 12px;
  border: 1px solid #34435e;
  background: rgba(14, 20, 32, 0.8);
  color: #dce7ff;
}

.related-card:hover {
  border-color: #5f7bbb;
}

.detail-tags {
  margin-top: 0;
  margin-bottom: 16px;
}

.detail-empty {
  text-align: center;
}

.detail-empty h1 {
  margin: 0 0 12px;
}

.detail-empty p {
  margin: 0 0 14px;
  color: var(--text-soft);
}

@media (max-width: 980px) {
  .featured-course {
    grid-template-columns: 1fr;
  }

  .featured-cover {
    min-height: 160px;
  }

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

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

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

@media (max-width: 760px) {
  .topbar-inner {
    min-height: auto;
    padding: 12px 0;
    flex-direction: column;
    align-items: flex-start;
  }

  .nav {
    width: 100%;
  }

  .page-main {
    padding-top: 20px;
  }

  .page-hero {
    padding: 18px 16px 20px;
    border-radius: 14px;
  }

  .panel {
    padding: 12px;
  }

  .card-meta {
    flex-direction: column;
    align-items: flex-start;
  }

  .meta-actions {
    width: 100%;
  }
}

body.modal-open {
  overflow: hidden;
}

.video-modal {
  position: fixed;
  inset: 0;
  display: none;
  z-index: 120;
}

.video-modal.is-open {
  display: block;
}

.video-modal__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.72);
}

.video-modal__panel {
  position: relative;
  width: min(980px, 92vw);
  margin: 6vh auto 0;
  background: linear-gradient(160deg, rgba(16, 21, 32, 0.97), rgba(10, 14, 22, 0.96));
  border: 1px solid #354766;
  border-radius: 14px;
  box-shadow: 0 24px 44px rgba(0, 0, 0, 0.5);
  overflow: hidden;
}

.video-modal__head {
  height: 54px;
  padding: 0 14px 0 18px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid #2d3a53;
}

.video-modal__head h3 {
  margin: 0;
  font-size: 16px;
  color: #f2f6ff;
}

.video-modal__close {
  width: 32px;
  height: 32px;
  border: 0;
  border-radius: 8px;
  background: rgba(25, 35, 56, 0.9);
  color: #dbe6ff;
  font-size: 22px;
  line-height: 1;
  cursor: pointer;
}

.video-modal__close:hover {
  background: rgba(49, 67, 104, 0.9);
}

.video-modal__body {
  padding: 12px;
}

.video-modal__body video {
  width: 100%;
  max-height: 72vh;
  border-radius: 10px;
  display: block;
  background: #000;
}

.video-fallback {
  margin-top: 12px;
  padding: 14px;
  border-radius: 10px;
  border: 1px solid #36445f;
  background: rgba(13, 19, 31, 0.8);
}

.video-fallback p {
  margin: 0 0 10px;
  color: var(--text-soft);
}

@media (max-width: 760px) {
  .video-modal__panel {
    margin-top: 4vh;
  }

  .video-modal__body {
    padding: 8px;
  }

  .panel-meta {
    align-items: flex-start;
  }
}