:root {
  --paper: #fbfaf7;
  --panel: #f5f3ec;
  --ink: #17150f;
  --sub: #57513f;
  --faint: #8f8977;
  --rule: #17150f;
  --hair: #d9d3c4;
  --grid: #e8e3d6;
  --ox: #24405e;      /* prussian: tickvault's ink */
  --ox-dim: #7189a3;
  --ok: #2f5d3a;
  --warn: #8a6d1f;
  --bad: #a33d2e;
  --serif: 'Times New Roman', Times, Georgia, serif;
  --mono: 'Courier New', Courier, monospace;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { background: var(--paper); color: var(--ink); font: 16px/1.5 var(--serif); }
a { color: var(--ink); }
a:hover { color: var(--ox); }
.gut { padding-left: clamp(20px, 3vw, 44px); padding-right: clamp(20px, 3vw, 44px); }
.eyebrow {
  font: 12px/1.6 var(--mono); letter-spacing: .14em; text-transform: uppercase;
  color: var(--sub); margin-bottom: 14px;
}

/* ---------- header ---------- */
header {
  display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  gap: clamp(24px, 4vw, 64px); align-items: end;
  padding-top: 34px; padding-bottom: 26px; border-bottom: 2px solid var(--rule);
}
h1 { font-size: clamp(38px, 6vw, 64px); font-weight: 400; letter-spacing: -.02em; line-height: 1; }
h1 .dot { color: var(--ox); }
.thesis { font-size: clamp(15px, 1.5vw, 18px); color: var(--sub); margin-top: 14px; max-width: 60ch; }
.thesis strong { color: var(--ink); font-weight: 400; border-bottom: 1px solid var(--ox); }

.facts { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 2px 18px; }
.fact { border-top: 1px solid var(--hair); padding-top: 8px; }
.fact dt { font: 11px/1.6 var(--mono); letter-spacing: .1em; text-transform: uppercase; color: var(--faint); }
.fact dd { font-size: 22px; }
.fact dd small { font-size: 13px; color: var(--sub); }

/* ---------- sections ---------- */
section { padding-top: 40px; padding-bottom: 40px; border-bottom: 1px solid var(--hair); }
h2 { font-size: clamp(22px, 2.6vw, 30px); font-weight: 400; margin-bottom: 6px; }
h3 { font-size: 18px; font-weight: 400; margin: 22px 0 6px; }
p { max-width: 74ch; margin-bottom: 12px; color: var(--sub); }
/* The intro to a figure sits alone above it, so a 74ch cap leaves most of a wide
   screen blank. It gets more room; body prose inside a split gets none. */
p.lead { color: var(--ink); max-width: 104ch; }

/* Prose beside a takeaway rather than a narrow column with a blank half.
   A wide screen should be used, not left empty. */
.split {
  display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
  gap: clamp(20px, 3vw, 46px); align-items: start; margin-top: 8px;
}
.split p { max-width: none; }
.takeaway { border-left: 2px solid var(--ox); padding: 2px 0 2px 16px; }
.takeaway dt {
  font: 11px/1.6 var(--mono); letter-spacing: .1em; text-transform: uppercase;
  color: var(--faint); margin-top: 12px;
}
.takeaway dt:first-child { margin-top: 0; }
.takeaway dd { font-size: 19px; line-height: 1.35; }
.takeaway dd small { display: block; font-size: 13px; color: var(--sub); margin-top: 2px; }
p strong { color: var(--ink); font-weight: 400; }
code { font: .9em var(--mono); background: var(--panel); padding: 1px 4px; }

/* ---------- the instrument ---------- */
.figure { border: 1px solid var(--rule); background: var(--panel); margin-top: 20px; }
.figcap {
  font: 11px/1.6 var(--mono); letter-spacing: .1em; text-transform: uppercase;
  color: var(--sub); padding: 8px 14px; border-bottom: 1px solid var(--hair);
  display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap;
}
.figcap b { color: var(--ink); font-weight: 400; }

.toolbar {
  display: flex; gap: 10px; align-items: center; flex-wrap: wrap;
  padding: 10px 14px; border-bottom: 1px solid var(--hair);
}
.venues { display: flex; flex-wrap: wrap; gap: 0; border: 1px solid var(--ink); }
.venues button {
  font: 12px/1 var(--mono); text-transform: uppercase; letter-spacing: .08em;
  background: transparent; color: var(--sub); border: 0; border-right: 1px solid var(--hair);
  padding: 8px 10px; cursor: pointer;
}
.venues button:last-child { border-right: 0; }
.venues button[aria-pressed="true"] { background: var(--ox); color: var(--paper); }
.venues button:disabled { color: var(--faint); cursor: wait; }

.scrub { display: flex; align-items: center; gap: 10px; flex: 1 1 320px; min-width: 240px; }
.scrub input[type=range] { flex: 1; accent-color: var(--ox); min-width: 120px; }
.scrub label { font: 11px/1 var(--mono); text-transform: uppercase; letter-spacing: .1em; color: var(--faint); }
.stepper { display: flex; gap: 0; border: 1px solid var(--ink); }
.stepper button {
  font: 13px/1 var(--mono); background: transparent; border: 0; color: var(--ink);
  padding: 7px 9px; cursor: pointer; border-right: 1px solid var(--hair);
}
.stepper button:last-child { border-right: 0; }
.stepper button:hover { background: var(--ox); color: var(--paper); }

.plot { display: block; width: 100%; height: auto; background: var(--paper); }

.readout {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  border-top: 1px solid var(--hair);
}
.readout div { padding: 9px 14px; border-right: 1px solid var(--hair); }
.readout div:last-child { border-right: 0; }
.readout dt { font: 10px/1.6 var(--mono); letter-spacing: .1em; text-transform: uppercase; color: var(--faint); }
.readout dd { font-size: 17px; }
.readout dd.small { font-size: 13px; color: var(--sub); }

.banner {
  padding: 9px 14px; border-top: 1px solid var(--hair);
  font: 12px/1.5 var(--mono); color: var(--sub);
}
.banner.suspect { background: #f6efdc; color: #6b5314; border-top: 1px solid #d8c48a; }
.banner.err { background: #f7e7e4; color: var(--bad); }

/* ---------- heatmap ---------- */
.grid-wrap { overflow-x: auto; padding: 14px; }
table.cov { border-collapse: collapse; font: 12px/1 var(--mono); }
table.cov th {
  font-weight: 400; text-align: right; padding: 3px 10px 3px 0; color: var(--sub);
  white-space: nowrap; text-transform: uppercase; letter-spacing: .08em; font-size: 11px;
}
table.cov td { padding: 0; }
.cell {
  width: 16px; height: 16px; display: block; border: 1px solid var(--hair); margin: 1px;
}
/* Colour is never load bearing: each state has its own fill pattern too. */
.cell.clean { background: var(--ok); border-color: var(--ok); }
.cell.suspect {
  background: repeating-linear-gradient(45deg, #8a6d1f 0 3px, #d9c07a 3px 6px);
  border-color: var(--warn);
}
.cell.unverifiable {
  background: repeating-linear-gradient(90deg, var(--paper) 0 3px, #c9c3b2 3px 4px);
  border-color: var(--faint);
}
.cell.absent { background: var(--paper); border-color: var(--bad); position: relative; }
.cell.absent::after {
  content: ''; position: absolute; inset: 3px;
  background: linear-gradient(45deg, transparent 44%, var(--bad) 44% 56%, transparent 56%),
              linear-gradient(-45deg, transparent 44%, var(--bad) 44% 56%, transparent 56%);
}
.legend { display: flex; gap: 18px; flex-wrap: wrap; padding: 0 14px 14px; font: 12px/1.4 var(--mono); color: var(--sub); }
.legend span { display: flex; align-items: center; gap: 6px; }

/* ---------- source map ---------- */
/* The parts doing the work, as a row of cards, so they read as a set and fill
   the width instead of stacking into one long narrow column. */
ul.map {
  list-style: none; display: grid; margin-top: 18px;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  border: 1px solid var(--rule); background: var(--panel);
}
ul.map li {
  padding: 14px 16px; color: var(--sub); font-size: 15px; line-height: 1.45;
  border-right: 1px solid var(--hair); border-bottom: 1px solid var(--hair);
}
ul.map li b { color: var(--ink); font-weight: 400; display: block; margin-bottom: 4px; }
ul.map li .where { display: block; margin-top: 8px; font: 11px var(--mono); color: var(--ox); }

footer {
  padding-top: 26px; padding-bottom: 40px;
  font: 12px/1.7 var(--mono); color: var(--sub);
  display: flex; justify-content: space-between; gap: 20px; flex-wrap: wrap;
}

@media (max-width: 860px) {
  header { grid-template-columns: minmax(0, 1fr); gap: 26px; }
  .facts { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

/* ---- shared nav shell ------------------------------------------------
   Written entirely in this page's own variables, so it takes the palette
   it is dropped into instead of importing a second one. */
html { scroll-padding-top: 96px; }
.topbar {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  backdrop-filter: blur(8px); border-bottom: 1px solid var(--rule);
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 10px clamp(20px, 3vw, 44px);
}
.brand { font: 15px/1 var(--serif); text-decoration: none; color: var(--ink); }
.brand span { color: var(--ox); }
.navlinks { display: flex; gap: 18px; font: 12px/1 var(--mono); letter-spacing: .06em; }
.navlinks a { color: var(--sub); text-decoration: none; transition: color .18s ease; }
.navlinks a:hover { color: var(--ox); }
.tabs {
  position: sticky; top: 40px; z-index: 19;
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  backdrop-filter: blur(8px); border-bottom: 1px solid var(--rule);
  display: flex; gap: 2px; overflow-x: auto; padding: 0 clamp(20px, 3vw, 44px);
}
.tabs a {
  flex: 0 0 auto; display: flex; align-items: center; min-height: 44px;
  padding: 0 13px; font: 11px/1 var(--mono); letter-spacing: .1em;
  text-transform: uppercase; color: var(--faint); text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: color .18s ease, border-color .18s ease;
}
.tabs a:hover { color: var(--sub); }
.tabs a[aria-current="true"] { color: var(--ox); border-bottom-color: var(--ox); }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .tabs a, .navlinks a { transition: none; }
}

/* Brand marks in the nav, sized to the text and inheriting its colour. */
.navlinks a { display: inline-flex; align-items: center; gap: 7px; }
.navlinks svg { width: 15px; height: 15px; flex: 0 0 auto; }
.brand { letter-spacing: .005em; }