:root {
  color-scheme: dark;
  --bg: #08101d;
  --surface: #0f1a2b;
  --surface-2: #142238;
  --text: #f5f7fb;
  --muted: #9ba9bc;
  --line: rgba(255,255,255,.1);
  --accent: #8bffb0;
  --accent-2: #65a8ff;
  --shadow: 0 22px 60px rgba(0,0,0,.28);
}

:root[data-theme="light"] {
  color-scheme: light;
  --bg: #f3f6fa;
  --surface: #ffffff;
  --surface-2: #eaf0f8;
  --text: #0d1727;
  --muted: #5e6d80;
  --line: rgba(13,23,39,.12);
  --accent: #087c43;
  --accent-2: #145bd6;
  --shadow: 0 20px 55px rgba(29,45,70,.12);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-width: 320px;
  min-height: 100vh;
  background:
    radial-gradient(circle at 82% 3%, color-mix(in srgb, var(--accent-2) 15%, transparent), transparent 28rem),
    var(--bg);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.5;
}

button, input { font: inherit; }
a { color: inherit; }
.skip-link { position: fixed; left: 1rem; top: -5rem; z-index: 20; background: var(--accent); color: #07150d; padding: .7rem 1rem; border-radius: .7rem; }
.skip-link:focus { top: 1rem; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.shell { width: min(1180px, calc(100% - 2rem)); margin: 0 auto; }

.topbar { height: 88px; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--line); }
.brand { display: inline-flex; align-items: center; gap: .8rem; text-decoration: none; font-weight: 650; letter-spacing: -.02em; }
.brand strong { color: var(--accent); }
.brand-mark { display: grid; place-items: center; width: 2.3rem; aspect-ratio: 1; border-radius: .72rem; background: var(--text); color: var(--bg); font-size: .78rem; font-weight: 900; letter-spacing: -.04em; transform: rotate(-4deg); }
.theme-toggle { display: inline-flex; align-items: center; gap: .5rem; border: 1px solid var(--line); border-radius: 999px; padding: .55rem .85rem; background: var(--surface); color: var(--muted); cursor: pointer; }
.theme-toggle:hover { color: var(--text); border-color: color-mix(in srgb, var(--accent) 50%, var(--line)); }

.intro { min-height: 385px; display: grid; grid-template-columns: 1.3fr .7fr; align-items: end; gap: 4rem; padding: 5rem 0 4rem; }
.eyebrow, .section-kicker { margin: 0 0 .8rem; color: var(--accent); text-transform: uppercase; letter-spacing: .16em; font-size: .75rem; font-weight: 800; }
h1 { margin: 0; max-width: 760px; font-size: clamp(3.2rem, 7vw, 6.7rem); line-height: .9; letter-spacing: -.075em; }
h1 span { color: var(--muted); }
.intro-copy { max-width: 410px; padding-bottom: .55rem; }
.intro-copy > p { margin: 0 0 1.6rem; color: var(--muted); font-size: 1.05rem; }
.stats { display: flex; flex-wrap: wrap; gap: .7rem; }
.stats span { padding: .65rem .85rem; border: 1px solid var(--line); border-radius: .8rem; color: var(--muted); font-size: .85rem; background: color-mix(in srgb, var(--surface) 70%, transparent); }
.stats strong { color: var(--text); font-size: 1rem; }

.workspace { padding: 2rem 0 5rem; }
.workspace-head { display: flex; align-items: end; justify-content: space-between; gap: 2rem; margin-bottom: 1.4rem; }
h2 { margin: 0; font-size: clamp(1.8rem, 3vw, 2.5rem); letter-spacing: -.045em; }
.search { width: min(100%, 360px); display: flex; align-items: center; gap: .65rem; padding: .8rem 1rem; border: 1px solid var(--line); border-radius: .9rem; background: var(--surface); color: var(--muted); }
.search:focus-within { outline: 2px solid color-mix(in srgb, var(--accent-2) 72%, transparent); outline-offset: 2px; }
.search input { width: 100%; border: 0; outline: 0; color: var(--text); background: transparent; }
.search input::placeholder { color: var(--muted); }
kbd { border: 1px solid var(--line); border-bottom-width: 2px; border-radius: .35rem; padding: .05rem .38rem; color: var(--muted); font: 600 .72rem ui-monospace, monospace; }
.filters { display: flex; gap: .5rem; overflow-x: auto; padding: .2rem 0 1.5rem; scrollbar-width: none; }
.filter { white-space: nowrap; border: 1px solid var(--line); border-radius: 999px; padding: .55rem .9rem; background: transparent; color: var(--muted); cursor: pointer; }
.filter:hover { color: var(--text); }
.filter.active { background: var(--text); color: var(--bg); border-color: var(--text); }

.course-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem; }
.course-card { min-height: 280px; display: flex; flex-direction: column; justify-content: space-between; padding: 1.25rem; border: 1px solid var(--line); border-radius: 1.2rem; background: var(--surface); text-decoration: none; box-shadow: 0 1px 0 rgba(255,255,255,.03) inset; transition: transform .2s ease, border-color .2s ease, box-shadow .2s ease; }
a.course-card:hover { transform: translateY(-4px); border-color: color-mix(in srgb, var(--accent-2) 60%, var(--line)); box-shadow: var(--shadow); }
.course-card:focus-visible { outline: 3px solid var(--accent-2); outline-offset: 3px; }
.course-card.featured { grid-column: span 2; background: linear-gradient(140deg, color-mix(in srgb, var(--accent-2) 15%, var(--surface)), var(--surface) 58%); }
.card-top, .card-foot { display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
.course-code { display: grid; place-items: center; width: 3rem; height: 3rem; border-radius: .9rem; background: var(--surface-2); color: var(--text); font-weight: 900; font-size: .82rem; letter-spacing: .04em; }
.status { padding: .34rem .58rem; border-radius: 999px; font-size: .72rem; font-weight: 750; }
.status.ready { color: var(--accent); background: color-mix(in srgb, var(--accent) 11%, transparent); }
.status.waiting { color: var(--muted); background: var(--surface-2); }
.card-body h3 { margin: 2.1rem 0 .55rem; font-size: 1.38rem; letter-spacing: -.035em; }
.featured .card-body h3 { font-size: 1.75rem; }
.card-body p { max-width: 440px; margin: 0; color: var(--muted); }
.card-foot { padding-top: 1.4rem; margin-top: 1rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .86rem; font-weight: 650; }
a.course-card:hover .card-foot { color: var(--text); }
.pending { border-style: dashed; background: color-mix(in srgb, var(--surface) 72%, transparent); }
.course-card[hidden] { display: none; }
.empty-state { padding: 3rem; border: 1px dashed var(--line); border-radius: 1rem; color: var(--muted); text-align: center; }

footer { display: flex; justify-content: space-between; gap: 1rem; padding: 1.7rem 0 2.5rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .8rem; }

.not-found { width: min(760px, calc(100% - 2rem)); min-height: 100vh; margin: 0 auto; display: flex; flex-direction: column; align-items: flex-start; justify-content: center; }
.not-found h1 { font-size: clamp(3rem, 9vw, 6rem); }
.not-found > p:not(.eyebrow) { color: var(--muted); font-size: 1.05rem; }
.not-found > a { margin-top: 1rem; padding: .75rem 1rem; border-radius: .75rem; background: var(--text); color: var(--bg); text-decoration: none; font-weight: 750; }

@media (max-width: 820px) {
  .intro { min-height: 0; grid-template-columns: 1fr; gap: 2rem; padding: 4rem 0 3rem; }
  .workspace-head { align-items: stretch; flex-direction: column; }
  .search { width: 100%; }
  .course-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .course-card.featured { grid-column: span 2; }
}

@media (max-width: 560px) {
  .shell { width: min(100% - 1.25rem, 1180px); }
  .topbar { height: 72px; }
  .theme-label { display: none; }
  h1 { font-size: clamp(3rem, 15vw, 4.8rem); }
  .course-grid { grid-template-columns: 1fr; }
  .course-card.featured { grid-column: auto; }
  .course-card { min-height: 245px; }
  footer { flex-direction: column; }
}

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