/* ============================================================
   course.css — shared lesson stylesheet (Ontology course)
   Aesthetic: "Working Ontologist's Reader"
   Parchment paper, ink text, one confident vermilion accent.
   Serif display + serif body + mono triples. Tufte-ish, print-ready.
   Every lesson links this file. Reuse, don't duplicate.
   ============================================================ */

:root {
  /* palette */
  --paper: #f6f1e7;
  --paper-2: #efe7d8;
  --ink: #1c1a17;
  --ink-soft: #3d3a34;
  --muted: #7a7468;
  --rule: #d8cdb9;
  --accent: #a63a1e;          /* vermilion — the working mark */
  --accent-soft: #efe0da;
  --good: #2f6b4f;
  --bad: #9c2f2f;
  --paper-elev: #fffdf8;

  /* fonts */
  --font-display: "Fraunces", "Iowan Old Style", "Times New Roman", serif;
  --font-body: "Newsreader", "Iowan Old Style", Georgia, serif;
  --font-mono: "IBM Plex Mono", "SF Mono", "Menlo", monospace;

  /* layout */
  --measure: 46rem;           /* reading column — widened */
  --page-max: 66rem;          /* widened page */
  --gutter: clamp(1.5rem, 4vw, 3rem);
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background:
    linear-gradient(180deg, rgba(0,0,0,0.02), transparent 240px),
    var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: clamp(1.02rem, 0.6vw + 0.9rem, 1.16rem);
  line-height: 1.66;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

/* --- page shell ------------------------------------------------- */
.lesson {
  max-width: var(--page-max);
  margin: 0 auto;
  padding: clamp(2rem, 6vw, 4rem) var(--gutter) calc(clamp(2rem, 6vw, 4rem) + 8rem);
}

.kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 1rem;
}
.kicker::before { content: ""; width: 1.6rem; height: 1px; background: var(--accent); }

.title {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(2.1rem, 5.5vw + 0.4rem, 3.5rem);
  line-height: 1.04;
  letter-spacing: -0.015em;
  margin: 0 0 1.4rem;
  text-wrap: balance;
}

.subtitle {
  font-family: var(--font-display);
  font-style: italic;
  font-weight: 400;
  font-size: clamp(1.1rem, 2vw + 0.6rem, 1.45rem);
  color: var(--ink-soft);
  margin: 0 0 2.6rem;
}

.lede {
  font-size: 1.14em;
  line-height: 1.7;
  color: var(--ink-soft);
  max-width: var(--measure);
  margin: 0 0 2.4rem;
}

.rule { border: 0; border-top: 1px solid var(--rule); margin: 2.6rem 0; }

/* --- prose ------------------------------------------------------ */
p { max-width: var(--measure); margin: 0 0 1.15rem; }
p, li, td { color: var(--ink-soft); }

h2 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(1.5rem, 3vw + 0.6rem, 2rem);
  line-height: 1.15;
  letter-spacing: -0.01em;
  margin: 3rem 0 0.9rem;
  text-wrap: balance;
}
h2 .num {
  font-family: var(--font-mono);
  font-size: 0.7em;
  color: var(--accent);
  letter-spacing: 0.12em;
  margin-right: 0.55rem;
  vertical-align: 0.06em;
  text-transform: uppercase;
}
h3 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.16rem;
  margin: 2rem 0 0.6rem;
}
h4 {
  font-family: var(--font-mono);
  font-style: normal;
  font-weight: 600;
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-soft);
  margin: 1.6rem 0 0.5rem;
}

strong { color: var(--ink); font-weight: 700; }

a { color: var(--accent); text-underline-offset: 0.14em; text-decoration-thickness: 0.7px; }
a:hover { color: var(--ink); }

ul, ol { max-width: var(--measure); padding-left: 1.3rem; }
li { margin-bottom: 0.4rem; }

mark, .hl {
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
  padding: 0 0.2em;
}

.term { font-weight: 700; color: var(--ink); border-bottom: 1px dotted var(--muted); }

code {
  font-family: var(--font-mono);
  font-size: 0.86em;
  background: var(--paper-2);
  color: var(--ink);
  padding: 0.1em 0.35em;
  border-radius: 3px;
}

/* --- inline citation (superscript) and references ---------------- */
.cite {
  font-family: var(--font-mono);
  font-size: 0.62em;
  vertical-align: 0.5em;
  color: var(--accent);
  text-decoration: none;
  letter-spacing: 0.02em;
  padding: 0 0.1em;
}
.cite:hover { color: var(--ink); }

.refs {
  max-width: var(--measure);
  font-size: 0.86em;
  color: var(--muted);
  margin-top: 1rem;
}
.refs li { margin-bottom: 0.5rem; }

/* --- sidenote: flow note with left rule -------------------------- */
.sidenote {
  max-width: var(--measure);
  font-size: 0.88em;
  line-height: 1.55;
  color: var(--muted);
  padding: 0.35rem 0 0.35rem 1rem;
  border-left: 2px solid var(--rule);
  margin: 1.3rem 0 1.3rem auto;
}
.sidenote strong { color: var(--ink-soft); }

/* --- callouts ---------------------------------------------------- */
.keypoint, .callout {
  max-width: var(--measure);
  padding: 1.1rem 1.25rem 1.05rem;
  margin: 1.8rem 0;
  border-radius: 4px;
  background: var(--paper-elev);
  box-shadow: 0 1px 0 rgba(0,0,0,0.04);
  border-left: 3px solid var(--accent);
}
.keypoint .tag, .callout .tag {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.5rem;
}
.keypoint p:last-child, .callout p:last-child { margin-bottom: 0; }
.callout { border-left-color: var(--muted); }
.callout .tag { color: var(--muted); }

/* --- diagram / figure -------------------------------------------- */
.diagram {
  max-width: 100%;
  margin: 2rem 0;
  padding: 1.4rem 1.5rem;
  background: var(--paper-elev);
  border: 1px solid var(--rule);
  border-radius: 6px;
  overflow-x: auto;
}
.diagram svg, .diagram .viz { display: block; }
.figcap {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  margin-top: 0.8rem;
}

/* --- triples / code blocks --------------------------------------- */
.triple, pre {
  max-width: 100%;
  overflow-x: auto;
  background: var(--paper-elev);
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: 1rem 1.2rem;
  margin: 1.6rem 0;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  line-height: 1.7;
  color: var(--ink-soft);
  tab-size: 2;
  white-space: pre-wrap;   /* 保留源码换行,长行才折行 */
  word-break: break-word;
}
.triple .s { color: var(--ink); font-weight: 600; }        /* subject */
.triple .p { color: var(--accent); }                        /* predicate */
.triple .o { color: var(--good); }                          /* object */
.triple .c { color: var(--muted); }                         /* comment */
.triple .c-grp { color: var(--good); font-weight: 600; }      /* grouped marker, e.g. 推理结果 */
.triple .kw { color: var(--accent); font-weight: 700; }     /* a, rdf:type */
.note-caption {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: var(--muted);
  margin-top: -1.2rem;
  margin-bottom: 1.6rem;
}

/* --- table ------------------------------------------------------- */
table {
  width: 100%;
  max-width: var(--measure);
  border-collapse: collapse;
  font-size: 0.92em;
  margin: 1.6rem 0 2rem;
}
th, td { text-align: left; padding: 0.55rem 0.7rem; border-bottom: 1px solid var(--rule); }
th { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); font-weight: 600; }
tbody tr:last-child td { border-bottom: 0; }

/* --- primary source card ----------------------------------------- */
.primary-source {
  display: block;
  max-width: var(--measure);
  padding: 1.2rem 1.3rem;
  margin: 2rem 0;
  background: var(--paper-elev);
  border: 1px solid var(--rule);
  border-radius: 6px;
  color: inherit;
  text-decoration: none;
  position: relative;
}
.primary-source:hover { border-color: var(--accent); }
.primary-source .ps-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.4rem;
}
.primary-source .ps-title { font-family: var(--font-display); font-weight: 600; font-size: 1.08rem; }
.primary-source .ps-url { font-family: var(--font-mono); font-size: 0.76rem; color: var(--muted); }
.primary-source .ps-why { font-size: 0.9em; color: var(--ink-soft); margin-top: 0.5rem; }

/* --- quiz widget ------------------------------------------------- */
.quiz {
  max-width: var(--measure);
  margin: 2rem 0;
  padding: 1.3rem 1.4rem;
  background: var(--paper-elev);
  border: 1px solid var(--rule);
  border-radius: 6px;
}
.quiz .quiz-q {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  line-height: 1.35;
  margin: 0 0 1rem;
}
.quiz .quiz-opts { display: grid; gap: 0.55rem; }
.quiz button.opt {
  font: inherit;
  text-align: left;
  padding: 0.65rem 0.85rem;
  border: 1px solid var(--rule);
  border-radius: 4px;
  background: transparent;
  color: var(--ink-soft);
  cursor: pointer;
  transition: border-color .15s, background .15s, color .15s;
}
.quiz button.opt:hover { border-color: var(--accent); color: var(--ink); }
.quiz button.opt.correct {
  border-color: var(--good); background: #eef4ef; color: var(--good); font-weight: 600;
}
.quiz button.opt.wrong {
  border-color: var(--bad); background: #f7ecec; color: var(--bad); font-weight: 600;
}
.quiz button.opt:disabled { cursor: default; opacity: .95; }
.quiz .quiz-fb {
  font-size: 0.9em;
  color: var(--ink-soft);
  margin: 0.8rem 0 0;
  min-height: 1.2em;
}
.quiz .quiz-fb.correct { color: var(--good); }
.quiz .quiz-fb.wrong { color: var(--bad); }

/* --- ask-agent reminder ------------------------------------------ */
.ask-agent {
  max-width: var(--measure);
  margin: 2.4rem 0 0;
  padding: 1.1rem 1.25rem;
  border: 1px dashed var(--accent);
  border-radius: 6px;
  background: var(--accent-soft);
}
.ask-agent .tag {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.4rem;
}
.ask-agent p { margin: 0; font-size: 0.95em; color: var(--ink-soft); }

/* --- lesson footer nav ------------------------------------------- */
.lesson-foot {
  margin-top: 3rem;
  padding-top: 1.6rem;
  border-top: 1px solid var(--rule);
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}
.lesson-foot a { font-family: var(--font-mono); font-size: 0.82rem; text-decoration: none; }
.lesson-foot .next { text-align: right; }

/* --- glossary term styling (used in reference docs) -------------- */
.gloss-term { max-width: var(--measure); margin: 1.4rem 0; }
.gloss-term .gl-head { display: flex; align-items: baseline; gap: 0.7rem; }
.gloss-term .gl-name { font-family: var(--font-display); font-weight: 600; font-size: 1.12rem; }
.gloss-term .avoid { font-family: var(--font-mono); font-size: 0.72rem; color: var(--muted); }
.gloss-term p { margin: 0.5rem 0 0; font-size: 0.98em; }
.gloss-term .gl-ex { margin: 0.6rem 0 0; font-size: 0.9em; color: var(--ink-soft); }
.gloss-term .gl-ex .glx { font-family: var(--font-mono); font-size: 0.72rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--accent); margin-right: 0.4rem; }

/* --- responsive / print ------------------------------------------ */
@media (max-width: 600px) {
  .cmd-hint { white-space: normal; }
}

@media print {
  body { background: #fff; color: #000; }
  .lesson { padding: 0; max-width: none; }
  .diagram, .triple, pre, .primary-source, .quiz, .ask-agent, .keypoint, .callout {
    box-shadow: none; background: #fff; border-color: #bbb; break-inside: avoid;
  }
  a { color: #000; text-decoration: none; }
  .ask-agent, .quiz button.opt:hover { border-color: #999; }
  .lesson-foot { break-before: avoid; }
}