/* Teacher: shared stylesheet for the hub, every lesson and every reference page.
   Change the look of the whole library here. */

:root {
  --bg: #fbfaf7;
  --surface: #ffffff;
  --text: #1f1d1a;
  --muted: #6b665e;
  --rule: #e4e0d8;
  --accent: #9b3d1f;        /* links, highlights */
  --accent-soft: #f6e9e2;
  --ok: #2f6f3e;
  --ok-soft: #e4f1e6;
  --bad: #a3292b;
  --bad-soft: #f8e3e3;
  --code-bg: #f1eee8;
  --track-it: #2c5d8a;
  --track-app: #7a4a9a;
  --track-data: #3d7a5c;
  --track-side: #9a6a1f;
  --serif: "Source Serif 4", Georgia, "Times New Roman", serif;
  --sans: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", Consolas, "Courier New", monospace;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #171614;
    --surface: #1f1d1b;
    --text: #ebe7e0;
    --muted: #a39d93;
    --rule: #34312d;
    --accent: #e39a78;
    --accent-soft: #3a2a22;
    --ok: #86c795;
    --ok-soft: #1f3324;
    --bad: #ec8f8f;
    --bad-soft: #3a2222;
    --code-bg: #262320;
    --track-it: #7fb0de;
    --track-app: #c49be0;
    --track-data: #86c7a5;
    --track-side: #dcb36e;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #171614; --surface: #1f1d1b; --text: #ebe7e0; --muted: #a39d93; --rule: #34312d;
  --accent: #e39a78; --accent-soft: #3a2a22; --ok: #86c795; --ok-soft: #1f3324;
  --bad: #ec8f8f; --bad-soft: #3a2222; --code-bg: #262320;
  --track-it: #7fb0de; --track-app: #c49be0; --track-data: #86c7a5; --track-side: #dcb36e;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 18px/1.6 var(--serif);
}
main, .page-header, .page-footer {
  max-width: 44rem;
  margin: 0 auto;
  padding: 0 16px;
}
main { padding-bottom: 3rem; }

/* ---------- Navigation header / footer ---------- */
.page-header {
  display: flex; flex-wrap: wrap; gap: .25rem 1rem; align-items: baseline;
  padding-top: 1.25rem; padding-bottom: .75rem;
  border-bottom: 1px solid var(--rule);
  font: 14px/1.4 var(--sans);
}
.page-header a { color: var(--muted); text-decoration: none; }
.page-header a:hover { color: var(--accent); }
.page-header .home { font-weight: 600; color: var(--text); }
.page-footer {
  display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap;
  border-top: 1px solid var(--rule);
  padding-top: 1rem; padding-bottom: 2rem;
  font: 14px/1.4 var(--sans);
}
.page-footer a { color: var(--accent); text-decoration: none; }
.page-footer .disabled { color: var(--muted); }

/* ---------- Typography ---------- */
h1, h2, h3 { font-family: var(--sans); line-height: 1.25; letter-spacing: -0.01em; }
h1 { font-size: 2rem; margin: 2rem 0 .25rem; }
h2 { font-size: 1.3rem; margin: 2.25rem 0 .5rem; }
h3 { font-size: 1.05rem; margin: 1.5rem 0 .25rem; }
.kicker {
  font: 600 12px/1 var(--sans); text-transform: uppercase; letter-spacing: .08em;
  color: var(--track-color, var(--accent)); margin-top: 2rem;
}
.lede { font-size: 1.15rem; color: var(--muted); margin-top: .25rem; }
a { color: var(--accent); }
code, pre, kbd { font-family: var(--mono); font-size: .85em; }
code { background: var(--code-bg); padding: .1em .3em; border-radius: 3px; }
pre {
  background: var(--code-bg); padding: .9rem 1rem; border-radius: 6px;
  overflow-x: auto; line-height: 1.45;
}
pre code { background: none; padding: 0; }
.hl { background: var(--accent-soft); color: var(--text); border-radius: 2px; padding: 0 .15em; }
table { border-collapse: collapse; width: 100%; font: 15px/1.45 var(--sans); margin: 1rem 0; }
th, td { text-align: left; padding: .45rem .6rem; border-bottom: 1px solid var(--rule); vertical-align: top; }
th { font-weight: 600; color: var(--muted); font-size: 13px; text-transform: uppercase; letter-spacing: .04em; }
.table-wrap { overflow-x: auto; }
.sidenote { font-size: .85rem; color: var(--muted); }
sup.cite a { text-decoration: none; font-family: var(--sans); font-size: .7em; }

/* Track colours */
.track-it   { --track-color: var(--track-it); }
.track-app  { --track-color: var(--track-app); }
.track-data { --track-color: var(--track-data); }
.track-side { --track-color: var(--track-side); }

/* ---------- Callouts ---------- */
.callout {
  border-left: 3px solid var(--track-color, var(--accent));
  background: var(--surface);
  padding: .75rem 1rem; margin: 1.25rem 0; border-radius: 0 6px 6px 0;
}
.callout > :first-child { margin-top: 0; }
.callout > :last-child { margin-bottom: 0; }
.callout .label { font: 600 12px/1 var(--sans); text-transform: uppercase; letter-spacing: .06em; color: var(--muted); display: block; margin-bottom: .4rem; }
.win { border-left-color: var(--ok); }
.source { border-left-color: var(--muted); font-size: .95rem; }
.ask { border-left-color: var(--accent); font-size: .95rem; }

/* ---------- Quiz widget (assets/quiz.js) ---------- */
.quiz {
  background: var(--surface); border: 1px solid var(--rule); border-radius: 8px;
  padding: 1rem 1.1rem; margin: 1.25rem 0;
}
.quiz .q { margin: 0 0 .75rem; font-weight: 600; font-family: var(--sans); font-size: 1rem; }
.quiz .q .num { color: var(--muted); font-weight: 400; margin-right: .35rem; }
.quiz .choices { list-style: none; padding: 0; margin: 0; display: grid; gap: .4rem; }
.quiz button.choice {
  width: 100%; text-align: left; cursor: pointer;
  font: 15px/1.4 var(--sans); color: var(--text);
  background: var(--bg); border: 1px solid var(--rule); border-radius: 6px;
  padding: .55rem .75rem;
}
.quiz button.choice:hover:not(:disabled) { border-color: var(--accent); }
.quiz button.choice:disabled { cursor: default; }
.quiz button.choice.right { background: var(--ok-soft); border-color: var(--ok); }
.quiz button.choice.wrong { background: var(--bad-soft); border-color: var(--bad); }
.quiz .explain { margin: .75rem 0 0; font-size: .95rem; }
.quiz .explain .verdict { font: 600 14px/1 var(--sans); margin-right: .35rem; }
.quiz .explain .verdict.ok { color: var(--ok); }
.quiz .explain .verdict.no { color: var(--bad); }
.quiz-score { font: 600 15px/1.4 var(--sans); color: var(--muted); margin-top: 1rem; }

/* Retrieval prompt: think first, then reveal */
details.recall {
  background: var(--surface); border: 1px dashed var(--rule); border-radius: 8px;
  padding: .75rem 1rem; margin: 1rem 0;
}
details.recall summary { cursor: pointer; font-family: var(--sans); font-size: 1rem; font-weight: 600; }
details.recall summary .hint { font-weight: 400; color: var(--muted); font-size: .85rem; margin-left: .35rem; }
details.recall[open] summary { margin-bottom: .5rem; }

/* ---------- Hub ---------- */
.hub-grid { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); margin: 1rem 0 2rem; }
.card {
  background: var(--surface); border: 1px solid var(--rule); border-radius: 10px;
  padding: 1rem 1.1rem; border-top: 4px solid var(--track-color, var(--rule));
  font-family: var(--sans); font-size: 15px;
}
.card h3 { margin: 0 0 .25rem; font-size: 1.05rem; }
.card p { margin: .25rem 0; color: var(--muted); }
.card.soon { opacity: .6; border-style: dashed; }
.meter { height: 6px; background: var(--rule); border-radius: 3px; overflow: hidden; margin: .6rem 0 .25rem; }
.meter > span { display: block; height: 100%; background: var(--track-color, var(--accent)); }
.lesson-list { list-style: none; padding: 0; margin: 0; font-family: var(--sans); font-size: 15px; }
.lesson-list li { display: flex; gap: .75rem; align-items: baseline; padding: .5rem 0; border-bottom: 1px solid var(--rule); }
.lesson-list .date { color: var(--muted); font-size: 13px; white-space: nowrap; min-width: 5.5rem; }
.lesson-list .tag { font-size: 12px; font-weight: 600; color: var(--track-color); white-space: nowrap; }
.lesson-list a { color: var(--text); text-decoration: none; }
.lesson-list a:hover { color: var(--accent); }
.empty { color: var(--muted); font-style: italic; }

/* ---------- Print ---------- */
@media print {
  :root { --bg: #fff; --surface: #fff; --text: #000; }
  body { font-size: 11pt; }
  .page-header, .page-footer, .no-print { display: none; }
  details.recall { display: block; }
  a { color: inherit; }
  .quiz, .callout, pre { break-inside: avoid; }
}