@charset "UTF-8";

:root {
  --ink: #17231e;
  --muted: #68736d;
  --paper: #f6f7f3;
  --surface: #ffffff;
  --line: #e2e6df;
  --green: #173f35;
  --green-2: #245a49;
  --lime: #d9f99d;
  --lime-strong: #bceb66;
  --orange: #e8784a;
  --shadow: 0 18px 50px rgba(23, 35, 30, .09);
  --sidebar: 232px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: Inter, "SF Pro Display", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif; -webkit-font-smoothing: antialiased; }
button, input, select { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
button { color: inherit; }
a { color: inherit; text-decoration: none; }
button { border: 0; background: none; cursor: pointer; }
svg { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.svg-sprite { position: absolute; width: 0; height: 0; overflow: hidden; }
.hidden { display: none !important; }
:focus-visible { outline: 3px solid #77a93d; outline-offset: 3px; }

.app-shell { min-height: 100vh; }
.sidebar { position: fixed; inset: 0 auto 0 0; z-index: 40; display: flex; flex-direction: column; width: var(--sidebar); padding: 30px 18px 22px; background: #fbfcf9; border-right: 1px solid var(--line); }
.brand { display: flex; align-items: center; gap: 10px; padding: 0 10px; font-size: 21px; font-weight: 800; letter-spacing: -.8px; }
.brand > span:last-child > span, .mobile-brand span { color: #4c7d43; }
.brand-mark { display: grid; place-items: center; width: 35px; height: 35px; color: var(--lime); background: var(--green); border-radius: 10px; transform: rotate(-3deg); }
.brand-mark svg { width: 24px; height: 24px; }
.nav-label { margin: 36px 12px 12px; color: #939b95; font-size: 11px; font-weight: 700; letter-spacing: 1.5px; }
.main-nav { display: grid; gap: 5px; }
.nav-item { display: flex; align-items: center; gap: 12px; width: 100%; min-height: 45px; padding: 0 12px; color: #59655e; border-radius: 10px; text-align: left; font-size: 14px; font-weight: 550; transition: .18s ease; }
.nav-item:hover { color: var(--green); background: #eef2e9; }
.nav-item.active { color: var(--green); background: #e8efdf; font-weight: 700; }
.nav-item svg { width: 19px; height: 19px; }
.nav-dot { width: 9px; height: 9px; margin: 0 5px; border-radius: 3px; transform: rotate(45deg); }
.dot-ai { background: #52886c; }
.dot-k12 { background: #e8a149; }
.dot-high { background: #d57063; }
.dot-alevel { background: #7182bb; }
.nav-count { margin-left: auto; color: #8a958e; font-size: 11px; font-variant-numeric: tabular-nums; }
.curation-card { position: relative; display: flex; flex-direction: column; align-items: flex-start; gap: 5px; margin-top: auto; padding: 18px 16px; overflow: hidden; color: #ecf5e9; background: var(--green); border-radius: 14px; text-align: left; }
.curation-card strong { margin-top: 8px; font-size: 13px; }
.curation-card > span:not(.curation-icon) { color: #a9c0b7; font-size: 11px; }
.curation-icon { display: grid; place-items: center; width: 28px; height: 28px; color: var(--green); background: var(--lime); border-radius: 50%; }
.curation-icon svg { width: 16px; height: 16px; stroke-width: 2.5; }
.curation-arrow { position: absolute; right: 14px; bottom: 16px; width: 17px; color: var(--lime); }
.sidebar-foot { margin: 18px 6px 0; color: #a0a8a2; font-size: 9px; line-height: 1.7; letter-spacing: .8px; }
.sidebar-scrim { display: none; }

.main-content { min-width: 0; margin-left: var(--sidebar); }
.topbar { position: sticky; top: 0; z-index: 30; display: flex; align-items: center; justify-content: center; min-height: 82px; padding: 16px clamp(24px, 4vw, 58px); background: rgba(246, 247, 243, .88); border-bottom: 1px solid rgba(226, 230, 223, .7); backdrop-filter: blur(16px); }
.search-box { display: flex; align-items: center; gap: 11px; width: min(100%, 580px); height: 46px; padding: 0 14px; background: var(--surface); border: 1px solid var(--line); border-radius: 12px; transition: .2s; }
.search-box:focus-within { border-color: #7b9c75; box-shadow: 0 0 0 3px rgba(95, 135, 83, .1); }
.search-box svg { flex: 0 0 auto; width: 19px; color: #748078; }
.search-box input { min-width: 0; flex: 1; color: var(--ink); background: none; border: 0; outline: 0; font-size: 13px; }
.search-box input::placeholder { color: #929b95; }
kbd { padding: 2px 7px; color: #89938c; background: #f3f5f1; border: 1px solid #e1e5df; border-radius: 5px; font: 11px inherit; }
.about-button { position: absolute; right: clamp(24px, 4vw, 58px); display: flex; align-items: center; gap: 7px; color: var(--muted); font-size: 12px; }
.about-button:hover { color: var(--green); }
.about-button svg { width: 18px; }
.icon-button { display: grid; place-items: center; width: 40px; height: 40px; padding: 0; border-radius: 50%; }
.icon-button:hover { background: rgba(113, 128, 118, .12); }
.menu-button, .mobile-brand { display: none; }
.page-content { width: min(100%, 1540px); margin: 0 auto; padding: 30px clamp(24px, 4vw, 58px) 60px; }

.hero { position: relative; display: grid; grid-template-columns: 1.25fr .75fr; min-height: 370px; padding: 48px 52px 0; overflow: hidden; color: #f5f8f3; background: var(--green); border-radius: 22px; isolation: isolate; }
.hero::before { position: absolute; inset: 0; z-index: -1; background-image: linear-gradient(rgba(217, 249, 157, .04) 1px, transparent 1px), linear-gradient(90deg, rgba(217, 249, 157, .04) 1px, transparent 1px); background-size: 42px 42px; content: ""; mask-image: linear-gradient(to right, transparent, #000); }
.hero-copy { padding-bottom: 110px; }
.eyebrow, .section-kicker { color: #6d7f72; font-size: 10px; font-weight: 750; letter-spacing: 2px; }
.eyebrow { display: flex; align-items: center; gap: 9px; color: #a9c1b6; }
.eyebrow span { width: 20px; height: 1px; background: var(--lime); }
.hero h1 { margin: 19px 0 17px; font-size: clamp(38px, 4.3vw, 63px); line-height: 1.13; letter-spacing: -2.8px; }
.hero h1 em { color: var(--lime); font-style: normal; }
.hero-copy > p { margin: 0; color: #b6c8c0; font-size: 14px; line-height: 1.9; }
.hero-actions { display: flex; gap: 10px; margin-top: 25px; }
.primary-button, .ghost-button, .secondary-button { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 43px; padding: 0 18px; border-radius: 10px; font-size: 13px; font-weight: 650; transition: .18s ease; }
.primary-button { color: var(--green); background: var(--lime); }
.primary-button:hover { background: var(--lime-strong); transform: translateY(-1px); }
.primary-button svg, .ghost-button svg { width: 17px; }
.ghost-button { color: #e6eee9; border: 1px solid rgba(230, 238, 233, .22); }
.ghost-button:hover { background: rgba(255, 255, 255, .07); }
.hero-visual { position: relative; min-height: 240px; }
.orbit { position: absolute; top: 46%; left: 52%; border: 1px solid rgba(217, 249, 157, .17); border-radius: 50%; transform: translate(-50%, -50%) rotate(-18deg); }
.orbit-one { width: 255px; height: 255px; }
.orbit-two { width: 340px; height: 150px; }
.hero-play { position: absolute; top: 46%; left: 52%; display: grid; place-items: center; width: 96px; height: 96px; color: var(--green); background: var(--lime); border-radius: 50%; box-shadow: 0 0 0 15px rgba(217, 249, 157, .06), 0 0 60px rgba(217, 249, 157, .12); transform: translate(-50%, -50%); }
.hero-play svg { width: 48px; height: 48px; }
.floating-tag { position: absolute; padding: 7px 12px; color: #dce8df; background: rgba(255, 255, 255, .08); border: 1px solid rgba(255, 255, 255, .12); border-radius: 8px; font-size: 10px; font-weight: 700; letter-spacing: .5px; backdrop-filter: blur(8px); }
.tag-one { top: 16%; left: 15%; transform: rotate(-8deg); }
.tag-two { top: 25%; right: 1%; transform: rotate(8deg); }
.tag-three { right: 5%; bottom: 23%; transform: rotate(-4deg); }
.hero-stats { position: absolute; inset: auto 0 0; display: grid; grid-template-columns: repeat(4, 1fr); min-height: 83px; padding: 0 52px; background: rgba(4, 25, 19, .22); border-top: 1px solid rgba(255, 255, 255, .08); }
.hero-stats > div { display: flex; align-items: center; gap: 10px; }
.hero-stats strong { color: #f2f7ed; font-size: 25px; font-weight: 650; letter-spacing: -1px; }
.hero-stats strong span { margin-left: 2px; font-size: 12px; }
.hero-stats div > span { color: #9fb6ac; font-size: 11px; }

.continue-section { margin-top: 40px; }
.section-heading { display: flex; align-items: flex-end; justify-content: space-between; gap: 20px; margin-bottom: 24px; }
.section-heading.compact { margin-bottom: 16px; }
.section-heading h2 { margin: 7px 0 0; font-size: clamp(25px, 2.5vw, 33px); line-height: 1.2; letter-spacing: -1.2px; }
.section-heading.compact h2 { font-size: 22px; }
.section-heading p { margin: 8px 0 0; color: var(--muted); font-size: 13px; }
.text-button { display: flex; align-items: center; gap: 6px; color: var(--muted); font-size: 12px; }
.text-button:hover { color: var(--green); }
.text-button svg { width: 16px; }
.continue-card { display: grid; grid-template-columns: 210px 1fr auto; align-items: center; gap: 20px; padding: 12px 16px 12px 12px; background: var(--surface); border: 1px solid var(--line); border-radius: 15px; }
.continue-thumb { position: relative; width: 210px; aspect-ratio: 16 / 9; overflow: hidden; border-radius: 9px; }
.continue-thumb img { width: 100%; height: 100%; object-fit: cover; }
.continue-thumb span { position: absolute; inset: 0; display: grid; place-items: center; color: white; background: rgba(12, 27, 21, .18); }
.continue-thumb svg { width: 38px; height: 38px; filter: drop-shadow(0 2px 5px #000); }
.continue-info { min-width: 0; }
.continue-info span { color: #6c8d62; font-size: 10px; font-weight: 700; }
.continue-info h3 { margin: 7px 0; overflow: hidden; font-size: 16px; text-overflow: ellipsis; white-space: nowrap; }
.continue-info p { margin: 0; color: var(--muted); font-size: 12px; }
.continue-open { display: flex; align-items: center; gap: 7px; padding: 10px 14px; color: var(--green); background: #edf3e5; border-radius: 9px; font-size: 12px; font-weight: 650; }
.continue-open svg { width: 17px; }

.library-section { padding-top: 52px; scroll-margin-top: 85px; }
.result-count { color: #879189; font-size: 12px; white-space: nowrap; }
.filter-row { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 24px; }
.subject-filters { display: flex; flex-wrap: wrap; gap: 8px; }
.filter-chip { min-height: 33px; padding: 0 13px; color: #657169; background: #eef0eb; border: 1px solid transparent; border-radius: 8px; font-size: 11px; transition: .15s; }
.filter-chip:hover { color: var(--green); background: #e6ebdf; }
.filter-chip.active { color: #eff8e8; background: var(--green); }
.sort-control { display: flex; align-items: center; gap: 8px; color: #8a948d; font-size: 11px; white-space: nowrap; }
.sort-control select { padding: 8px 28px 8px 10px; color: #526057; background: var(--surface); border: 1px solid var(--line); border-radius: 8px; outline: 0; font-size: 11px; cursor: pointer; }
.video-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 28px 20px; }
.video-card { min-width: 0; animation: card-in .35s both; }
@keyframes card-in { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
.thumbnail-button { position: relative; display: block; width: 100%; padding: 0; overflow: hidden; aspect-ratio: 16 / 9; background: #dce2d9; border-radius: 12px; }
.thumbnail-button img { width: 100%; height: 100%; object-fit: cover; transition: transform .35s ease, filter .35s; }
.video-card:hover .thumbnail-button img { transform: scale(1.035); filter: brightness(.82); }
.card-category { position: absolute; top: 10px; left: 10px; padding: 5px 8px; color: white; background: rgba(16, 33, 26, .7); border: 1px solid rgba(255, 255, 255, .14); border-radius: 6px; font-size: 9px; font-weight: 650; backdrop-filter: blur(8px); }
.card-play { position: absolute; top: 50%; left: 50%; display: grid; place-items: center; width: 46px; height: 46px; color: var(--green); background: rgba(228, 250, 192, .95); border-radius: 50%; opacity: 0; transform: translate(-50%, -42%) scale(.9); transition: .2s; }
.card-play svg { width: 28px; height: 28px; }
.video-card:hover .card-play, .thumbnail-button:focus-visible .card-play { opacity: 1; transform: translate(-50%, -50%) scale(1); }
.card-duration { position: absolute; right: 8px; bottom: 8px; padding: 4px 6px; color: white; background: rgba(12, 24, 19, .74); border-radius: 5px; font-size: 9px; font-variant-numeric: tabular-nums; }
.card-body { padding: 12px 2px 0; }
.card-meta { display: flex; align-items: center; gap: 6px; min-width: 0; color: #7b867e; font-size: 10px; }
.card-meta .subject-name { color: #55794c; font-weight: 700; }
.card-meta i { width: 2px; height: 2px; background: #9ca69f; border-radius: 50%; }
.card-title { display: -webkit-box; width: 100%; min-height: 42px; margin: 7px 0 8px; padding: 0; overflow: hidden; font-size: 14px; font-weight: 680; line-height: 1.5; letter-spacing: -.15px; text-align: left; -webkit-line-clamp: 2; -webkit-box-orient: vertical; }
.card-title:hover { color: #3e6c43; }
.card-footer { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.card-owner { min-width: 0; overflow: hidden; color: #8a938d; font-size: 10px; text-overflow: ellipsis; white-space: nowrap; }
.save-button { display: grid; flex: 0 0 auto; place-items: center; width: 28px; height: 28px; margin: -5px -4px -5px 0; color: #8b958e; border-radius: 50%; }
.save-button svg { width: 16px; height: 16px; }
.save-button:hover { color: var(--green); background: #e9eee4; }
.save-button.saved { color: #477547; }
.save-button.saved svg { fill: currentColor; }
.empty-state { padding: 65px 20px; text-align: center; }
.empty-mark { display: grid; place-items: center; width: 58px; height: 58px; margin: auto; color: #75816f; background: #e8ece3; border-radius: 50%; }
.empty-state h3 { margin: 18px 0 6px; font-size: 20px; }
.empty-state p { margin: 0 0 22px; color: var(--muted); font-size: 13px; }
.empty-state .primary-button { color: white; background: var(--green); }
.load-more-wrap { display: flex; justify-content: center; padding-top: 34px; }
.load-more { display: flex; align-items: center; gap: 8px; min-height: 40px; padding: 0 19px; color: #5d6a61; background: var(--surface); border: 1px solid var(--line); border-radius: 10px; font-size: 12px; }
.load-more:hover { color: var(--green); border-color: #a9b7a2; }
.load-more svg { width: 16px; transform: rotate(90deg); }

.principles { display: grid; grid-template-columns: 1.25fr repeat(3, 1fr); gap: 25px; margin-top: 76px; padding: 34px 36px; background: #ecefe7; border: 1px solid #e0e5da; border-radius: 17px; }
.principles h2 { margin: 9px 0; font-size: 26px; letter-spacing: -1px; }
.principles-intro p { max-width: 280px; margin: 0; color: var(--muted); font-size: 12px; line-height: 1.7; }
.principle { display: flex; gap: 12px; padding-top: 7px; }
.principle > span { color: #8fa383; font: 700 11px/1.4 ui-monospace, monospace; }
.principle h3 { margin: 0 0 7px; font-size: 13px; }
.principle p { margin: 0; color: #748077; font-size: 11px; line-height: 1.7; }
.footer { display: flex; align-items: center; justify-content: space-between; gap: 25px; margin: 0 clamp(24px, 4vw, 58px); padding: 25px 0 30px; border-top: 1px solid var(--line); }
.footer > div { display: flex; align-items: center; gap: 13px; }
.footer strong { font-size: 14px; }
.footer span, .footer p { color: #8b958e; font-size: 10px; }
.footer p { margin: 0; text-align: right; }
.mobile-nav { display: none; }

.player-dialog, .about-dialog { max-width: none; max-height: none; padding: 0; color: var(--ink); background: transparent; border: 0; }
.player-dialog { width: min(1180px, calc(100vw - 40px)); }
.player-dialog::backdrop, .about-dialog::backdrop { background: rgba(10, 20, 15, .78); backdrop-filter: blur(8px); }
.player-dialog[open], .about-dialog[open] { display: block; animation: dialog-in .2s ease-out; }
@keyframes dialog-in { from { opacity: 0; transform: translateY(10px) scale(.99); } to { opacity: 1; transform: none; } }
.dialog-shell { overflow: hidden; background: #f8f9f5; border-radius: 17px; box-shadow: 0 30px 100px #0008; }
.player-topbar { display: flex; align-items: center; justify-content: space-between; height: 52px; padding: 0 12px 0 20px; background: #101a16; }
.source-pill { color: #a8b9b0; font-size: 10px; letter-spacing: .5px; }
.player-topbar .icon-button { color: #d4ded8; }
.player-topbar .icon-button:hover { background: #ffffff15; }
.player-frame { aspect-ratio: 16 / 9; background: #08100d; }
.player-frame iframe { display: block; width: 100%; height: 100%; border: 0; }
.player-details { display: grid; grid-template-columns: 1fr 320px; gap: 30px; padding: 26px 28px 28px; }
.video-badges { display: flex; flex-wrap: wrap; gap: 6px; }
.video-badges span { padding: 4px 7px; color: #587050; background: #e9efe2; border-radius: 5px; font-size: 9px; font-weight: 650; }
.player-main h2 { margin: 11px 0 8px; font-size: 23px; line-height: 1.35; letter-spacing: -.6px; }
.player-owner { margin: 0; color: #79867d; font-size: 11px; }
.player-reason { max-width: 690px; margin: 17px 0 0; color: #59675e; font-size: 12px; line-height: 1.8; }
.player-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 20px; }
.secondary-button { min-height: 36px; padding: 0 12px; color: #536258; background: white; border: 1px solid #dfe5db; font-size: 11px; }
.secondary-button:hover { color: var(--green); border-color: #9bac91; }
.secondary-button svg { width: 15px; height: 15px; }
.secondary-button.saved { color: #42683e; background: #eaf2df; }
.secondary-button.saved svg { fill: currentColor; }
.up-next { min-width: 0; padding-left: 24px; border-left: 1px solid #e0e5dd; }
.up-next-heading { display: flex; justify-content: space-between; margin-bottom: 10px; font-size: 11px; font-weight: 700; }
.up-next-heading span { color: #99a29c; font-size: 9px; font-weight: 400; }
.next-item { display: grid; grid-template-columns: 84px 1fr; gap: 10px; width: 100%; padding: 8px 0; text-align: left; }
.next-item img { width: 84px; aspect-ratio: 16 / 9; object-fit: cover; border-radius: 6px; }
.next-item span { display: -webkit-box; align-self: center; overflow: hidden; font-size: 10px; line-height: 1.5; -webkit-line-clamp: 2; -webkit-box-orient: vertical; }
.next-item:hover span { color: #477345; }
.about-dialog { width: min(610px, calc(100vw - 32px)); }
.about-shell { position: relative; padding: 44px 46px; background: #f8f9f5; border-radius: 18px; box-shadow: var(--shadow); }
.about-close { position: absolute; top: 15px; right: 15px; }
.about-shell h2 { margin: 12px 0 20px; font-size: 35px; line-height: 1.25; letter-spacing: -1.5px; }
.about-shell > p { color: #66736a; font-size: 13px; line-height: 1.85; }
.about-list { display: grid; gap: 0; margin: 25px 0; border-top: 1px solid var(--line); }
.about-list > div { display: grid; grid-template-columns: 90px 1fr; gap: 15px; padding: 17px 0; border-bottom: 1px solid var(--line); }
.about-list strong { font-size: 12px; }
.about-list span { color: #748077; font-size: 11px; line-height: 1.7; }
.about-note { padding: 13px 15px; background: #edf0e8; border-radius: 8px; font-size: 10px !important; }
.toast { position: fixed; bottom: 30px; left: 50%; z-index: 100; padding: 11px 18px; color: white; background: #173f35; border-radius: 9px; box-shadow: var(--shadow); opacity: 0; pointer-events: none; transform: translate(-50%, 12px); transition: .2s; font-size: 12px; }
.toast.show { opacity: 1; transform: translate(-50%, 0); }

@media (max-width: 1280px) {
  :root { --sidebar: 210px; }
  .video-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .hero { min-height: 350px; }
  .hero-stats { padding: 0 40px; }
  .principles { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 960px) {
  :root { --sidebar: 224px; }
  .sidebar { transform: translateX(-100%); transition: transform .25s ease; }
  .sidebar.open { transform: translateX(0); }
  .sidebar-scrim { position: fixed; inset: 0; z-index: 35; background: rgba(16, 28, 22, .45); }
  .sidebar-scrim.visible { display: block; }
  .main-content { margin-left: 0; }
  .topbar { justify-content: flex-start; gap: 14px; min-height: 72px; }
  .menu-button { display: grid; flex: 0 0 auto; }
  .search-box { margin: 0 auto; }
  .about-button { position: static; }
  .about-button span { display: none; }
  .hero { padding: 40px 38px 0; }
  .hero-stats { padding: 0 38px; }
  .hero-visual { opacity: .75; }
  .principles { margin-top: 55px; }
  .player-details { grid-template-columns: 1fr; }
  .up-next { display: none; }
}

@media (max-width: 680px) {
  body { padding-bottom: 66px; }
  .topbar { gap: 8px; min-height: 64px; padding: 10px 15px; }
  .menu-button { display: none; }
  .mobile-brand { display: block; flex: 0 0 auto; padding: 0; font-size: 16px; font-weight: 800; letter-spacing: -.6px; }
  .search-box { height: 40px; padding: 0 10px; border-radius: 10px; }
  .search-box input { font-size: 12px; }
  .search-box kbd, .about-button { display: none; }
  .page-content { padding: 17px 15px 35px; }
  .hero { display: block; min-height: 460px; padding: 30px 24px 0; border-radius: 17px; }
  .hero-copy { position: relative; z-index: 2; padding-bottom: 145px; }
  .eyebrow { font-size: 8px; letter-spacing: 1.5px; }
  .hero h1 { margin: 18px 0 14px; font-size: 40px; letter-spacing: -2px; }
  .hero-copy > p { font-size: 12px; }
  .hero-actions { margin-top: 22px; }
  .primary-button, .ghost-button { min-height: 40px; padding: 0 14px; font-size: 11px; }
  .hero-visual { position: absolute; top: 165px; right: -45px; width: 230px; opacity: .22; }
  .hero-play { width: 75px; height: 75px; }
  .orbit-one { width: 190px; height: 190px; }
  .orbit-two { width: 240px; }
  .floating-tag { display: none; }
  .hero-stats { grid-template-columns: repeat(4, 1fr); min-height: 70px; padding: 0 12px; }
  .hero-stats > div { flex-direction: column; justify-content: center; gap: 2px; }
  .hero-stats strong { font-size: 20px; }
  .hero-stats div > span { font-size: 8px; }
  .continue-section { margin-top: 30px; }
  .continue-card { grid-template-columns: 118px 1fr; gap: 12px; padding: 9px; }
  .continue-thumb { width: 118px; }
  .continue-info h3 { font-size: 12px; white-space: normal; }
  .continue-info p { font-size: 9px; }
  .continue-open { display: none; }
  .section-heading { align-items: flex-start; margin-bottom: 18px; }
  .section-heading h2 { font-size: 25px; }
  .section-heading p { font-size: 11px; }
  .result-count { padding-top: 24px; font-size: 10px; }
  .library-section { padding-top: 40px; }
  .filter-row { align-items: flex-start; margin-right: -15px; }
  .subject-filters { flex-wrap: nowrap; padding-right: 15px; overflow-x: auto; scrollbar-width: none; }
  .subject-filters::-webkit-scrollbar { display: none; }
  .filter-chip { flex: 0 0 auto; }
  .sort-control { display: none; }
  .video-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 23px 11px; }
  .thumbnail-button { border-radius: 9px; }
  .card-category { top: 6px; left: 6px; padding: 3px 5px; font-size: 8px; }
  .card-duration { right: 5px; bottom: 5px; font-size: 8px; }
  .card-play { display: none; }
  .card-body { padding-top: 9px; }
  .card-title { min-height: 38px; margin: 5px 0; font-size: 12px; line-height: 1.5; }
  .card-meta, .card-owner { font-size: 9px; }
  .card-meta .lessons-meta { display: none; }
  .card-meta i:nth-of-type(2) { display: none; }
  .save-button { width: 24px; height: 24px; }
  .principles { grid-template-columns: 1fr; gap: 18px; margin-top: 48px; padding: 25px; }
  .principles-intro p { max-width: none; }
  .principle { padding-top: 0; }
  .footer { display: block; margin: 0 15px; padding-bottom: 20px; }
  .footer p { margin-top: 12px; line-height: 1.6; text-align: left; }
  .mobile-nav { position: fixed; inset: auto 0 0; z-index: 32; display: grid; grid-template-columns: repeat(4, 1fr); height: 64px; padding-bottom: env(safe-area-inset-bottom); background: rgba(251, 252, 249, .96); border-top: 1px solid var(--line); backdrop-filter: blur(16px); }
  .mobile-nav button { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 3px; color: #7b867e; font-size: 9px; }
  .mobile-nav button.active { color: var(--green); }
  .mobile-nav svg { width: 20px; height: 20px; }
  .player-dialog { width: 100vw; height: 100dvh; margin: 0; }
  .dialog-shell { min-height: 100%; border-radius: 0; }
  .player-frame { margin-top: 0; }
  .player-details { padding: 20px; }
  .player-main h2 { font-size: 20px; }
  .player-actions { gap: 6px; }
  .secondary-button { padding: 0 10px; font-size: 10px; }
  .about-dialog { width: calc(100vw - 24px); max-height: calc(100dvh - 30px); }
  .about-shell { padding: 38px 25px 28px; }
  .about-shell h2 { font-size: 29px; }
  .about-list > div { grid-template-columns: 75px 1fr; }
  .toast { bottom: 82px; white-space: nowrap; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; transition-duration: .01ms !important; }
}