:root {
  --bg: #f5f3ee;
  --bg-elev: #fbfaf7;
  --ink: #1a1c19;
  --ink-2: #474a44;
  --ink-3: #74776f;
  --line: #dcd9cf;
  --chip: #ebe8df;
  --accent: #b9501b;
  --accent-ink: #ffffff;
  --accent-soft: #f3e1d4;
  --open: #2f7a52;
  --open-soft: #dcefe2;
  --danger: #a3361f;
  --topo: 64, 96, 78;
  --shadow: 0 1px 0 rgba(0,0,0,.03), 0 8px 24px -12px rgba(30,28,20,.18);
  --serif: "Instrument Serif", ui-serif, Georgia, serif;
  --sans: "Geist", ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "Geist Mono", ui-monospace, "SF Mono", Menlo, monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1210;
    --bg-elev: #161a17;
    --ink: #e8e6df;
    --ink-2: #b6b5ad;
    --ink-3: #85877f;
    --line: #272c28;
    --chip: #1d221e;
    --accent: #ee7b40;
    --accent-ink: #1a0f08;
    --accent-soft: #2c1d14;
    --open: #5cc28a;
    --open-soft: #15291d;
    --danger: #f08a6c;
    --topo: 140, 180, 155;
    --shadow: 0 1px 0 rgba(255,255,255,.02), 0 10px 30px -14px rgba(0,0,0,.6);
    color-scheme: dark;
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
  font: 400 16px/1.6 var(--sans);
  -webkit-font-smoothing: antialiased;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  opacity: .5;
  background:
    repeating-radial-gradient(ellipse 120% 80% at 85% -10%, transparent 0 22px, rgba(var(--topo), .10) 22px 23px),
    repeating-radial-gradient(ellipse 90% 70% at -10% 110%, transparent 0 26px, rgba(var(--topo), .08) 26px 27px);
  -webkit-mask-image: linear-gradient(to bottom, #000, transparent 70%);
          mask-image: linear-gradient(to bottom, #000, transparent 70%);
}
a { color: inherit; text-decoration-color: color-mix(in srgb, var(--accent) 55%, transparent); text-underline-offset: 3px; text-decoration-thickness: 1.5px; }
a:hover { color: var(--accent); }

.wrap { max-width: 600px; margin: 0 auto; padding: 0 16px; }

header.top {
  display: flex; justify-content: space-between; align-items: center; gap: 12px;
  padding: 22px 0 0;
  font: 500 12px/1 var(--mono); letter-spacing: .06em; text-transform: uppercase; color: var(--ink-3);
}
header.top .mark { display: inline-flex; align-items: center; gap: 8px; color: var(--ink); text-decoration: none; }
header.top .mark svg { width: 20px; height: 20px; }
header.top a.home { text-decoration: none; }

h1 {
  font: 400 clamp(40px, 9vw, 58px)/1.02 var(--serif);
  letter-spacing: -.01em;
  margin: 56px 0 14px;
}
h1 em { color: var(--accent); font-style: italic; }
.lede { color: var(--ink-2); font-size: 17px; margin: 0 0 32px; max-width: 34em; }

.card {
  background: var(--bg-elev);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: var(--shadow);
  padding: 20px;
}

.step + .step { border-top: 1px dashed var(--line); margin-top: 20px; padding-top: 20px; }
.label {
  display: block;
  font: 500 11px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase; color: var(--ink-3);
  margin: 0 0 8px;
}
.label b { color: var(--accent); font-weight: 500; margin-right: 6px; }

.row { display: flex; gap: 8px; flex-wrap: wrap; }
.row > * { min-width: 0; }

input[type="text"], input[type="email"], select {
  font: inherit; color: var(--ink);
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 10px 12px;
  height: 44px;
  outline: none;
  transition: border-color .15s, box-shadow .15s;
}
input:focus, select:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
#code { flex: 1 1 140px; font-family: var(--mono); text-transform: uppercase; }
#code::placeholder { text-transform: none; }
#term { flex: 0 1 160px; }
#email { flex: 1 1 220px; }

button {
  font: 600 15px/1 var(--sans);
  height: 44px; padding: 0 18px;
  border-radius: 9px; border: 1px solid transparent;
  cursor: pointer;
  transition: transform .06s, filter .15s, background .15s;
}
button:active { transform: translateY(1px); }
button:disabled { opacity: .55; cursor: progress; }
.btn-primary { background: var(--accent); color: var(--accent-ink); }
.btn-primary:hover { filter: brightness(1.06); }
.btn-ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--ink-3); }

.course-head { display: flex; justify-content: space-between; align-items: baseline; gap: 12px; margin: 0 0 12px; }
.course-head h2 { font: 400 26px/1.15 var(--serif); margin: 0; }
.course-head .code { font: 500 13px/1 var(--mono); color: var(--ink-3); white-space: nowrap; }

.sections { list-style: none; margin: 0; padding: 0; display: grid; gap: 6px; }
.sec {
  display: grid; grid-template-columns: 22px 1fr auto; gap: 10px; align-items: center;
  padding: 10px 12px;
  border: 1px solid var(--line); border-radius: 10px;
  cursor: pointer;
  transition: border-color .15s, background .15s;
}
.sec:hover { border-color: var(--ink-3); }
.sec.checked { border-color: var(--accent); background: color-mix(in srgb, var(--accent-soft) 55%, transparent); }
.sec input { width: 18px; height: 18px; margin: 0; accent-color: var(--accent); }
.sec .what { line-height: 1.35; }
.sec .what b { font-weight: 600; }
.sec .what span { display: block; font-size: 13.5px; color: var(--ink-3); }
.pill {
  font: 500 12px/1 var(--mono); white-space: nowrap;
  padding: 6px 8px; border-radius: 999px;
  background: var(--chip); color: var(--ink-2);
}
.pill.open { background: var(--open-soft); color: var(--open); }

.note { font-size: 14px; color: var(--ink-2); margin: 10px 0 0; }
.note.open { color: var(--open); }
.error { color: var(--danger); font-size: 14.5px; margin: 10px 0 0; }
.chips { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 8px; }
.chips button {
  height: auto; padding: 6px 9px;
  font: 500 12.5px/1 var(--mono);
  background: var(--chip); color: var(--ink-2); border-radius: 7px;
}
.chips button:hover { color: var(--accent); }

.done { text-align: left; }
.done h2 { font: 400 30px/1.1 var(--serif); margin: 0 0 8px; }
.done p { margin: 0 0 8px; color: var(--ink-2); }

.how { margin: 44px 0 0; padding: 0; list-style: none; display: grid; gap: 14px; }
.how li { display: grid; grid-template-columns: 34px 1fr; gap: 6px; color: var(--ink-2); font-size: 15px; }
.how li::before { content: attr(data-n); font: 500 12px/1.9 var(--mono); color: var(--accent); }

footer {
  margin: 48px 0 0; padding: 18px 0 32px;
  border-top: 1px solid var(--line);
  display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap;
  font: 400 12.5px/1.5 var(--mono); color: var(--ink-3);
}
.live-dot { display: inline-block; width: 7px; height: 7px; border-radius: 50%; background: var(--open); margin-right: 6px; vertical-align: 1px; }
.live-dot.stale { background: var(--ink-3); }

[hidden] { display: none !important; }

@media (max-width: 480px) {
  h1 { margin-top: 40px; }
  .card { padding: 16px; }
  #term { flex: 1 1 100%; }
  .row > button { flex: 1 1 auto; }
}