/* Drawing Machines — shared tokens & primitives
   ============================================== */

:root {
  /* Color */
  --bg:        #f5f3ee;
  --bg-2:      #ebe8e0;
  --ink:       #0f0f0f;
  --ink-2:     #2a2a2a;
  --muted:     #6b6862;
  --rule:      #d6d2c7;
  --rule-2:    #c4bfb3;
  --accent:    #f5c518;
  --accent-ink:#0f0f0f;
  --warn:      #e63946;

  /* Type */
  --sans: "Space Grotesk", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;

  /* Spacing */
  --rail: 240px;
  --pad:  32px;
  --maxw: 1240px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  font-feature-settings: "ss01", "ss02", "cv11";
  text-rendering: optimizeLegibility;
}

a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid var(--ink);
}
a:hover { background: var(--accent); }

/* Mono labels */
.mono   { font-family: var(--mono); font-feature-settings: "tnum"; }
.tabular{ font-variant-numeric: tabular-nums; }
.label  {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink);
  font-weight: 500;
}
.label--muted { color: var(--muted); }

/* Display type */
.display {
  font-family: var(--sans);
  font-weight: 500;
  letter-spacing: -0.02em;
  line-height: 0.95;
  text-wrap: balance;
}
h1, h2, h3, h4 {
  font-family: var(--sans);
  font-weight: 500;
  letter-spacing: -0.01em;
  margin: 0;
}
h1 { font-size: 64px; line-height: 0.95; letter-spacing: -0.025em; }
h2 { font-size: 32px; line-height: 1.05; letter-spacing: -0.02em; }
h3 { font-size: 20px; line-height: 1.2; }
h4 { font-size: 14px; line-height: 1.3; }
p  { margin: 0; }

/* Hairline rules */
.rule    { border: 0; border-top: 1px solid var(--rule); margin: 0; }
.rule--2 { border: 0; border-top: 1px solid var(--rule-2); margin: 0; }
.rule--ink { border: 0; border-top: 1px solid var(--ink); margin: 0; }

/* Section number label (e.g. "01 ─── SYLLABUS") */
.section-label {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ink);
}
.section-label .num { color: var(--ink); }
.section-label .dash { flex: 0 0 32px; height: 1px; background: var(--ink); }

/* Specimen-style metadata grid */
.meta-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 0;
  border-top: 1px solid var(--ink);
  border-bottom: 1px solid var(--ink);
}
.meta-grid > div {
  padding: 14px 16px 16px;
  border-right: 1px solid var(--rule);
  min-width: 0;
}
.meta-grid > div:last-child { border-right: 0; }
.meta-grid .k {
  display: block;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 6px;
}
.meta-grid .v {
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.2;
  letter-spacing: -0.01em;
  font-weight: 500;
}
.meta-grid .v.mono {
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 400;
}

/* Layout: sidebar + main */
.layout {
  display: grid;
  grid-template-columns: var(--rail) 1fr;
  min-height: 100vh;
}
.sidebar {
  position: sticky;
  top: 0;
  align-self: start;
  height: 100vh;
  padding: 24px 20px 24px 24px;
  border-right: 1px solid var(--rule);
  background: var(--bg);
  display: flex;
  flex-direction: column;
  gap: 28px;
  overflow-y: auto;
}
.brand {
  display: block;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  border: 0;
}
.brand:hover { background: transparent; color: var(--ink); }
.brand-mark {
  display: flex;
  align-items: center;
  gap: 8px;
}
.brand-dot {
  width: 10px; height: 10px; background: var(--accent); border-radius: 50%;
  display: inline-block;
}

.nav { display: flex; flex-direction: column; gap: 2px; }
.nav .nav-section {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  padding: 8px 0 4px;
}
.nav a {
  border: 0;
  display: grid;
  grid-template-columns: 32px 1fr auto;
  align-items: baseline;
  padding: 6px 8px 6px 0;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.02em;
  color: var(--ink);
  border-radius: 0;
  position: relative;
}
.nav a .ix { color: var(--muted); }
.nav a .nm { color: var(--ink); }
.nav a .st { color: var(--muted); font-size: 10px; }
.nav a:hover { background: transparent; color: var(--ink); }
.nav a:hover .nm { background: var(--accent); padding: 0 4px; margin: 0 -4px; }
.nav a.active .nm {
  background: var(--ink);
  color: var(--bg);
  padding: 1px 6px;
  margin: 0 -6px;
}
.nav a.active .ix { color: var(--ink); }

.nav-sub {
  display: flex;
  flex-direction: column;
  gap: 1px;
  padding: 2px 0 6px 32px;
}
.nav-sub a {
  border: 0;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.02em;
  color: var(--muted);
  padding: 3px 6px;
}
.nav-sub a:hover {
  color: var(--ink);
  background: var(--accent);
}
.nav-sub a.active {
  color: var(--ink);
}

.sidebar-foot {
  margin-top: auto;
  font-family: var(--mono);
  font-size: 10px;
  color: var(--muted);
  line-height: 1.5;
}

/* Main column */
.main {
  padding: 0 var(--pad) 80px;
  max-width: var(--maxw);
}

/* Top strip */
.topstrip {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 0;
  border-bottom: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}
.topstrip .right { display: flex; gap: 18px; }
.topstrip a { border: 0; color: var(--muted); }
.topstrip a:hover { color: var(--ink); background: transparent; }

/* Pill / tag */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 4px 8px;
  border: 1px solid var(--ink);
  border-radius: 999px;
  color: var(--ink);
  background: transparent;
}
.tag--accent { background: var(--accent); border-color: var(--ink); }
.tag--ink { background: var(--ink); color: var(--bg); }

/* Card */
.card {
  border: 1px solid var(--rule);
  padding: 20px;
  background: var(--bg);
}
.card--ink {
  border-color: var(--ink);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 10px 14px;
  border: 1px solid var(--ink);
  background: var(--bg);
  color: var(--ink);
  cursor: pointer;
}
.btn--accent { background: var(--accent); }
.btn:hover { background: var(--ink); color: var(--bg); }

/* List of links / contents */
.toc {
  display: grid;
  border-top: 1px solid var(--ink);
}
.toc a {
  display: grid;
  grid-template-columns: 48px 1fr auto;
  gap: 12px;
  align-items: baseline;
  padding: 14px 4px;
  border-bottom: 1px solid var(--rule);
  border-top: 0;
  font-family: var(--sans);
  color: var(--ink);
  text-decoration: none;
}
.toc a:hover { background: var(--accent); }
.toc a .num { font-family: var(--mono); font-size: 12px; color: var(--muted); }
.toc a .ttl { font-size: 22px; font-weight: 500; letter-spacing: -0.01em; }
.toc a .meta { font-family: var(--mono); font-size: 11px; color: var(--muted); text-transform: uppercase; letter-spacing: 0.06em; }

/* Plot crosshair / corner marks (TE flourish) */
.corner-marks {
  position: relative;
}
.corner-marks::before,
.corner-marks::after,
.corner-marks > .cm-tl,
.corner-marks > .cm-br {
  content: "";
  position: absolute;
  width: 10px; height: 10px;
  border: 1px solid var(--ink);
}
.corner-marks::before { top: -1px; left: -1px; border-right: 0; border-bottom: 0; }
.corner-marks::after  { bottom: -1px; right: -1px; border-left: 0; border-top: 0; }

/* Utility */
.row   { display: flex; }
.col   { display: flex; flex-direction: column; }
.gap-8 { gap: 8px; }
.gap-16{ gap: 16px; }
.gap-24{ gap: 24px; }
.gap-32{ gap: 32px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mt-32 { margin-top: 32px; }
.mt-48 { margin-top: 48px; }
.mt-64 { margin-top: 64px; }
.muted { color: var(--muted); }
.accent-bg { background: var(--accent); }
.ink-bg    { background: var(--ink); color: var(--bg); }

/* Diagram defaults */
svg.diagram { display: block; max-width: 100%; height: auto; }
.diagram text { font-family: var(--mono); font-size: 11px; }

/* Footer */
.foot {
  margin-top: 80px;
  padding-top: 24px;
  border-top: 1px solid var(--ink);
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 24px;
  font-family: var(--mono);
  font-size: 11px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.foot .col-3 { display: flex; flex-direction: column; gap: 6px; }
.foot a { border: 0; color: var(--muted); }
.foot a:hover { color: var(--ink); background: transparent; }

/* Hide scrollbar on sidebar lightly */
.sidebar::-webkit-scrollbar { width: 6px; }
.sidebar::-webkit-scrollbar-thumb { background: var(--rule-2); }

/* Small screens — collapse sidebar */
@media (max-width: 860px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar {
    position: static;
    height: auto;
    border-right: 0;
    border-bottom: 1px solid var(--rule);
  }
  .main { padding: 0 20px 60px; }
  h1 { font-size: 44px; }
}