/* course.css — shared stylesheet for the AI Engineering course.
   Tufte-inspired: serif body, generous margins, readable measure, calm palette.
   Every lesson and reference doc links this file so the course reads as one work. */

:root {
  --ink:        #1a1a1a;
  --ink-soft:   #4a4a4a;
  --ink-faint:  #767676;
  --bg:         #fdfcf9;
  --rule:       #e3e0d8;
  --accent:     #7a1f1f;   /* deep oxblood — links, emphasis */
  --accent-soft:#f3e9e9;
  --accent-bg:  #f7efe9;
  --good:       #1f6b3a;
  --bad:        #9b2226;
  --code-bg:    #f3f1ea;
  --tag-bg:     #efe7dc;
  --measure:    38rem;      /* ~66 characters */
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, "Times New Roman", serif;
  --sans:  ui-sans-serif, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono:  "Cascadia Code", "SF Mono", Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--serif);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.55;
  font-size: 1.125rem;
  margin: 0;
  padding: 3.5rem 1.5rem 6rem;
}

.wrap { max-width: var(--measure); margin: 0 auto; }
.wrap-wide { max-width: 52rem; margin: 0 auto; }

/* ---- Masthead ---- */
.masthead { margin-bottom: 2.5rem; }
.eyebrow {
  font-family: var(--sans);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin: 0 0 0.6rem;
}
h1 {
  font-weight: 600;
  font-size: 2.1rem;
  line-height: 1.15;
  margin: 0 0 0.4rem;
  letter-spacing: -0.01em;
}
.subtitle {
  font-style: italic;
  color: var(--ink-soft);
  font-size: 1.15rem;
  margin: 0.2rem 0 0;
}

h2 {
  font-weight: 600;
  font-size: 1.4rem;
  margin: 2.6rem 0 0.8rem;
  padding-bottom: 0.3rem;
  border-bottom: 1px solid var(--rule);
}
h3 { font-weight: 600; font-size: 1.12rem; margin: 1.8rem 0 0.5rem; }

p { margin: 0 0 1.1rem; }
a { color: var(--accent); text-decoration: none; border-bottom: 1px solid rgba(122,31,31,0.28); }
a:hover { border-bottom-color: var(--accent); }

strong { font-weight: 600; }
em { font-style: italic; }

ul, ol { padding-left: 1.4rem; margin: 0 0 1.1rem; }
li { margin: 0.35rem 0; }

code {
  font-family: var(--mono);
  font-size: 0.86em;
  background: var(--code-bg);
  padding: 0.1em 0.35em;
  border-radius: 4px;
}
pre {
  font-family: var(--mono);
  font-size: 0.82rem;
  line-height: 1.5;
  background: var(--code-bg);
  border: 1px solid var(--rule);
  border-radius: 8px;
  padding: 1rem 1.1rem;
  overflow-x: auto;
}
pre code { background: none; padding: 0; }

kbd {
  font-family: var(--mono);
  font-size: 0.8em;
  background: #fff;
  border: 1px solid var(--rule);
  border-bottom-width: 2px;
  border-radius: 4px;
  padding: 0.05em 0.4em;
}

/* ---- Mission tag: ties a lesson to the FDE mission ---- */
.mission-tag {
  display: inline-block;
  font-family: var(--sans);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--tag-bg);
  border-radius: 999px;
  padding: 0.28em 0.8em;
  margin-bottom: 1.2rem;
}

/* ---- Data tables ---- */
.table-wrap { overflow-x: auto; margin: 1.4rem 0; }
table.data {
  border-collapse: collapse;
  width: 100%;
  font-family: var(--sans);
  font-size: 0.88rem;
  background: #fff;
  border: 1px solid var(--rule);
  border-radius: 10px;
}
table.data th {
  text-align: left;
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
  padding: 0.6rem 0.9rem;
  border-bottom: 2px solid var(--rule);
}
table.data td {
  padding: 0.55rem 0.9rem;
  border-bottom: 1px solid var(--rule);
}
table.data tr:last-child td { border-bottom: none; }
table.data td.num { font-family: var(--mono); font-size: 0.82rem; white-space: nowrap; }

/* ---- Callouts ---- */
.callout {
  border-left: 3px solid var(--accent);
  background: var(--accent-bg);
  padding: 0.9rem 1.1rem;
  border-radius: 0 8px 8px 0;
  margin: 1.4rem 0;
  font-size: 0.98rem;
}
.callout .label {
  font-family: var(--sans);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  display: block;
  margin-bottom: 0.35rem;
}
.aside {
  font-family: var(--sans);
  font-size: 0.85rem;
  color: var(--ink-soft);
  background: #f6f4ee;
  border-radius: 8px;
  padding: 0.8rem 1rem;
  margin: 1.4rem 0;
}
.aside .label {
  font-weight: 600; color: var(--ink); text-transform: uppercase;
  letter-spacing: 0.08em; font-size: 0.68rem; display:block; margin-bottom: 0.3rem;
}

/* ---- Citations ---- */
sup.cite { font-family: var(--sans); font-size: 0.62rem; line-height: 0; }
sup.cite a { border: none; font-weight: 600; }
.refs { font-family: var(--sans); font-size: 0.82rem; color: var(--ink-soft); }
.refs ol { padding-left: 1.2rem; }
.refs li { margin: 0.3rem 0; }

/* ---- Primary source card ---- */
.primary-source {
  border: 1px solid var(--rule);
  border-radius: 10px;
  padding: 1.1rem 1.2rem;
  margin: 1.6rem 0;
  background: #fff;
}
.primary-source .label {
  font-family: var(--sans); font-size: 0.68rem; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--ink-faint); display:block; margin-bottom: 0.4rem;
}
.primary-source .title { font-weight: 600; font-size: 1.05rem; }
.primary-source .why { font-size: 0.92rem; color: var(--ink-soft); margin-top: 0.3rem; }

/* ---- Quiz component (see assets/quiz.js) ---- */
.quiz {
  border: 1px solid var(--rule);
  border-radius: 10px;
  padding: 1.2rem 1.3rem;
  margin: 1.6rem 0;
  background: #fff;
}
.quiz-q { font-weight: 600; margin: 0 0 0.9rem; }
.quiz-scenario {
  font-size: 0.92rem; color: var(--ink-soft); font-style: italic;
  margin: 0 0 0.7rem;
}
.quiz-options { list-style: none; padding: 0; margin: 0; }
.quiz-options li {
  font-family: var(--sans);
  font-size: 0.95rem;
  border: 1px solid var(--rule);
  border-radius: 8px;
  padding: 0.6rem 0.85rem;
  margin: 0.5rem 0;
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s;
}
.quiz-options li:hover { background: #faf8f2; border-color: #cfc9bb; }
.quiz-options li.correct {
  background: #eaf5ee; border-color: var(--good); color: var(--good); cursor: default;
}
.quiz-options li.incorrect {
  background: #f7eaea; border-color: var(--bad); color: var(--bad);
}
.quiz-options li.locked { cursor: default; }
.quiz-feedback {
  font-family: var(--sans);
  font-size: 0.9rem;
  margin-top: 0.9rem;
  padding: 0.7rem 0.9rem;
  border-radius: 8px;
  background: #f6f4ee;
}
.quiz-feedback.right { background: #eaf5ee; color: var(--good); }
.quiz-feedback.wrong { background: #f7eaea; color: var(--bad); }

/* ---- Navigation / footer ---- */
.lesson-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: space-between;
  margin-top: 3rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--rule);
  font-family: var(--sans);
  font-size: 0.9rem;
}
.ask-teacher {
  font-family: var(--sans);
  font-size: 0.92rem;
  background: var(--accent-bg);
  border-radius: 10px;
  padding: 1rem 1.2rem;
  margin: 2.2rem 0 0;
  color: var(--ink-soft);
}
.ask-teacher strong { color: var(--accent); }

/* ---- Reference / glossary layout ---- */
.glossary-term {
  border-bottom: 1px solid var(--rule);
  padding: 0.9rem 0;
}
.glossary-term dt {
  font-weight: 600;
  font-size: 1.05rem;
}
.glossary-term .aka { font-style: italic; color: var(--ink-faint); font-size: 0.9rem; font-weight: 400; }
.glossary-term dd { margin: 0.3rem 0 0; color: var(--ink-soft); font-size: 0.98rem; }

/* ---- Audiobook player (MP3s generated via narration/generate.py) ----
   Sticky: stays pinned below the top edge while the reader scrolls,
   so play/pause/scrub are always reachable during read-along. */
.audio-player {
  position: sticky;
  top: 0.6rem;
  z-index: 40;
  border: 1px solid var(--rule);
  border-radius: 10px;
  background: #fff;
  padding: 0.8rem 1rem;
  margin: 0 0 1.6rem;
  box-shadow: 0 3px 14px rgba(0,0,0,0.07);
}
.audio-player .label {
  font-family: var(--sans);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-faint);
  display: block;
  margin-bottom: 0.45rem;
}
.audio-player audio {
  width: 100%;
  height: 2.4rem;
  display: block;
}

/* Read-along highlight (driven by assets/audiobook.js) */
.narrating {
  background: var(--accent-bg);
  border-radius: 6px;
  box-shadow: 0 0 0 7px var(--accent-bg);
  transition: background 0.25s, box-shadow 0.25s;
}

/* ---- Print ---- */
@media print {
  :root { --bg: #fff; }
  body { padding: 0; font-size: 11pt; color: #000; }
  a { color: #000; border: none; }
  .quiz-options li { break-inside: avoid; }
  .lesson-nav, .ask-teacher, .audio-player { display: none; }
  h2 { break-after: avoid; }
}

@media (max-width: 480px) {
  body { padding: 2rem 1.1rem 4rem; font-size: 1.05rem; }
  h1 { font-size: 1.7rem; }
}