/* Shared stylesheet for the GPU Architecture course.
   Tufte-inspired: serif body, generous measure, restrained colour, print-friendly.
   Linked by every lesson and reference doc so the course reads as one thing. */

:root {
  --ink: #201c18;
  --ink-soft: #5a5148;
  --bg: #fdfaf4;
  --rule: #e2d9c9;
  --card: #ffffff;
  --accent: #7a5c1e;        /* warm gold-brown, NVIDIA-adjacent restraint */
  --accent-soft: #f3ead6;
  --phys: #1f6f6b;          /* physical / hardware colour */
  --phys-soft: #e2f0ef;
  --logic: #8a3a52;         /* logical / CUDA colour */
  --logic-soft: #f6e6ea;
  --good: #2f7d4f;
  --bad: #a33a2a;
  --code-bg: #f3efe6;
  --measure: 40rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #ece5d8;
    --ink-soft: #b3a893;
    --bg: #191714;
    --rule: #3a3428;
    --card: #221f1a;
    --accent: #d8b25e;
    --accent-soft: #322a17;
    --phys: #5fc8c1;
    --phys-soft: #16302e;
    --logic: #d98aa2;
    --logic-soft: #331d24;
    --good: #6fca8f;
    --bad: #e08b7c;
    --code-bg: #262219;
  }
}
:root[data-theme="dark"] {
  --ink: #ece5d8; --ink-soft: #b3a893; --bg: #191714; --rule: #3a3428;
  --card: #221f1a; --accent: #d8b25e; --accent-soft: #322a17;
  --phys: #5fc8c1; --phys-soft: #16302e; --logic: #d98aa2; --logic-soft: #331d24;
  --good: #6fca8f; --bad: #e08b7c; --code-bg: #262219;
}
:root[data-theme="light"] {
  --ink: #201c18; --ink-soft: #5a5148; --bg: #fdfaf4; --rule: #e2d9c9;
  --card: #ffffff; --accent: #7a5c1e; --accent-soft: #f3ead6;
  --phys: #1f6f6b; --phys-soft: #e2f0ef; --logic: #8a3a52; --logic-soft: #f6e6ea;
  --good: #2f7d4f; --bad: #a33a2a; --code-bg: #f3efe6;
}

* { box-sizing: border-box; }

body {
  margin: 0 auto;
  padding: 4rem 2rem 6rem;
  max-width: var(--measure);
  background: var(--bg);
  color: var(--ink);
  font-family: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, "Times New Roman", serif;
  font-size: 1.125rem;
  line-height: 1.62;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* ---- Course header / breadcrumb ---- */
.kicker {
  font-family: ui-sans-serif, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 700;
  margin: 0 0 0.6rem;
}
h1 {
  font-size: 2.15rem;
  line-height: 1.12;
  margin: 0 0 0.4rem;
  letter-spacing: -0.01em;
}
.subtitle {
  color: var(--ink-soft);
  font-style: italic;
  font-size: 1.2rem;
  margin: 0 0 2rem;
}
h2 {
  font-family: ui-sans-serif, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 1.28rem;
  letter-spacing: -0.01em;
  margin: 2.8rem 0 0.8rem;
  padding-bottom: 0.3rem;
  border-bottom: 1px solid var(--rule);
}
h3 {
  font-family: ui-sans-serif, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 1.05rem;
  margin: 1.8rem 0 0.5rem;
}
p { margin: 0 0 1.1rem; }
a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
strong { font-weight: 700; }
em { font-style: italic; }

/* ---- Colour-coded vocabulary ---- */
.phys { color: var(--phys); font-weight: 600; }
.logic { color: var(--logic); font-weight: 600; }
.op { color: var(--accent); font-weight: 600; }   /* operational / systems layer (driver, runtime) */
.term {
  font-family: ui-sans-serif, -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 0.92em;
  font-weight: 600;
}

/* ---- Callouts ---- */
.callout {
  background: var(--accent-soft);
  border-left: 3px solid var(--accent);
  padding: 1rem 1.2rem;
  margin: 1.6rem 0;
  border-radius: 0 6px 6px 0;
}
.callout.key { border-color: var(--accent); }
.callout .label {
  font-family: ui-sans-serif, -apple-system, sans-serif;
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-weight: 700;
  color: var(--accent);
  display: block;
  margin-bottom: 0.35rem;
}
.callout p:last-child { margin-bottom: 0; }

/* ---- Sidenote-ish aside ---- */
.aside {
  font-size: 0.95rem;
  color: var(--ink-soft);
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  padding: 0.8rem 0;
  margin: 1.6rem 0;
}

/* ---- Two-column physical vs logical table ---- */
.maptable { width: 100%; border-collapse: collapse; margin: 1.6rem 0; font-size: 1rem; }
.maptable th, .maptable td { text-align: left; padding: 0.6rem 0.8rem; border-bottom: 1px solid var(--rule); vertical-align: top; }
.maptable thead th { font-family: ui-sans-serif, sans-serif; font-size: 0.85rem; }
.maptable .col-phys { color: var(--phys); }
.maptable .col-logic { color: var(--logic); }

/* ---- Comparison cards (CPU vs GPU etc.) ---- */
.compare { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin: 1.6rem 0; }
.compare .card {
  background: var(--card);
  border: 1px solid var(--rule);
  border-radius: 8px;
  padding: 1.1rem 1.2rem;
}
.compare .card h4 { margin: 0 0 0.6rem; font-family: ui-sans-serif, sans-serif; font-size: 1rem; }
.compare .card ul { margin: 0; padding-left: 1.1rem; }
.compare .card li { margin-bottom: 0.4rem; font-size: 0.98rem; }
@media (max-width: 34rem) { .compare { grid-template-columns: 1fr; } }

/* ---- Code ---- */
code {
  font-family: "SF Mono", "JetBrains Mono", "Cascadia Code", Consolas, monospace;
  font-size: 0.86em;
  background: var(--code-bg);
  padding: 0.12em 0.38em;
  border-radius: 4px;
}
pre {
  background: var(--code-bg);
  padding: 1rem 1.2rem;
  border-radius: 8px;
  overflow-x: auto;
  font-size: 0.92rem;
  line-height: 1.5;
}
pre code { background: none; padding: 0; }

/* ---- Citations ---- */
.cite { font-size: 0.82rem; color: var(--ink-soft); }
sup.ref a { text-decoration: none; font-weight: 700; color: var(--accent); }

/* ---- Nav row between lessons ---- */
.lesson-nav {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin: 3rem 0 0;
  padding-top: 1.2rem;
  border-top: 1px solid var(--rule);
  font-family: ui-sans-serif, sans-serif;
  font-size: 0.9rem;
}
.lesson-nav a { text-decoration: none; }

/* ---- Footer / ask-your-teacher ---- */
.teacher-note {
  margin-top: 3rem;
  background: var(--phys-soft);
  border-radius: 8px;
  padding: 1.1rem 1.3rem;
  font-size: 0.98rem;
}
.teacher-note strong { color: var(--phys); }

/* ---- Primary source block ---- */
.primary-source {
  margin: 1.6rem 0;
  padding: 1rem 1.2rem;
  border: 1px dashed var(--rule);
  border-radius: 8px;
  background: var(--card);
}
.primary-source .label {
  font-family: ui-sans-serif, sans-serif; font-size: 0.7rem; letter-spacing: 0.12em;
  text-transform: uppercase; font-weight: 700; color: var(--ink-soft); display: block; margin-bottom: 0.3rem;
}

/* ---- Progress dots ---- */
.progress { display: flex; gap: 0.4rem; margin: 0 0 2rem; align-items: center; }
.progress .dot { width: 9px; height: 9px; border-radius: 50%; background: var(--rule); }
.progress .dot.done { background: var(--accent); }
.progress .dot.here { background: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.progress .label { font-family: ui-sans-serif, sans-serif; font-size: 0.75rem; color: var(--ink-soft); margin-left: 0.5rem; }

/* ---- Quiz widget (see quiz.js) ---- */
.quiz {
  background: var(--card);
  border: 1px solid var(--rule);
  border-radius: 10px;
  padding: 1.3rem 1.4rem;
  margin: 1.8rem 0;
}
.quiz .q { font-weight: 600; margin: 0 0 1rem; }
.quiz .q .tag {
  display: inline-block; font-family: ui-sans-serif, sans-serif; font-size: 0.66rem;
  letter-spacing: 0.1em; text-transform: uppercase; color: var(--accent);
  border: 1px solid var(--accent); border-radius: 4px; padding: 0.05rem 0.4rem; margin-right: 0.5rem; vertical-align: 0.12em;
}
.quiz button {
  display: block; width: 100%; text-align: left; margin: 0.45rem 0;
  padding: 0.7rem 0.9rem; font: inherit; font-size: 0.98rem;
  background: var(--bg); color: var(--ink);
  border: 1px solid var(--rule); border-radius: 7px; cursor: pointer;
  transition: border-color 0.12s, background 0.12s;
}
.quiz button:hover:enabled { border-color: var(--accent); }
.quiz button:disabled { cursor: default; opacity: 0.85; }
.quiz button.is-correct { border-color: var(--good); background: color-mix(in srgb, var(--good) 12%, var(--bg)); }
.quiz button.picked-wrong { border-color: var(--bad); background: color-mix(in srgb, var(--bad) 12%, var(--bg)); }
.quiz button.is-correct::after { content: "  ✓"; color: var(--good); font-weight: 700; }
.quiz button.picked-wrong::after { content: "  ✗"; color: var(--bad); font-weight: 700; }
.quiz .explain {
  margin: 1rem 0 0; padding-top: 0.9rem; border-top: 1px solid var(--rule);
  font-size: 0.95rem; color: var(--ink-soft);
}

@media print {
  body { padding: 0; max-width: 100%; font-size: 11pt; color: #000; background: #fff; }
  .quiz, .teacher-note, .lesson-nav { break-inside: avoid; }
  a { color: #000; }
}