/* Probability on the Titanic: academic report styling */

:root {
  --paper: #f6f4ef;
  --panel: #fbfaf6;
  --ink: #1d1d1b;
  --muted: #5b5b57;
  --rule: #d8d4ca;
  --accent: #1f3a5f;
  --accent-soft: #e7ebf2;
  --survived: #2f6b4f;
  --died: #9a3b2e;
  --chip: #efede6;
  --focus: #1f3a5f;
  --serif: "Source Serif 4", "Source Serif Pro", Georgia, serif;
  --sans: "IBM Plex Sans", "Helvetica Neue", Arial, sans-serif;
  --mono: "IBM Plex Mono", "SFMono-Regular", Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #151514;
    --panel: #1c1c1a;
    --ink: #e9e7e0;
    --muted: #a5a39b;
    --rule: #3b3b37;
    --accent: #9db8d9;
    --accent-soft: #232a35;
    --survived: #79b494;
    --died: #d18a7b;
    --chip: #262624;
    --focus: #9db8d9;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 17.5px;
  line-height: 1.6;
}

.wrap { max-width: 1180px; margin: 0 auto; padding: 0 20px; }

.skip-link {
  position: absolute; left: -9999px; top: 0;
  background: var(--accent); color: var(--paper);
  padding: 8px 14px; font-family: var(--sans); font-size: 14px; z-index: 10;
}
.skip-link:focus { left: 8px; top: 8px; }

a { color: var(--accent); }
a:hover { text-decoration-thickness: 2px; }

/* ---------- header ---------- */

.site-header { border-bottom: 2px solid var(--ink); padding: 48px 0 28px; }
.kicker {
  font-family: var(--sans); font-size: 12.5px; letter-spacing: 0.12em;
  text-transform: uppercase; color: var(--muted); margin: 0 0 10px;
}
.site-header h1 {
  font-size: clamp(30px, 5vw, 44px); font-weight: 700; margin: 0 0 6px;
  letter-spacing: -0.01em; line-height: 1.15;
}
.subtitle { font-size: 19px; color: var(--muted); margin: 0 0 18px; font-style: italic; }
.abstract { max-width: 68ch; margin: 0 0 26px; }

.key-figures {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  gap: 0; margin: 0; border-top: 1px solid var(--rule);
}
.key-figure { padding: 12px 18px 12px 0; border-bottom: 1px solid var(--rule); }
.key-figure + .key-figure { padding-left: 18px; border-left: 1px solid var(--rule); }
.key-figure dt {
  font-family: var(--sans); font-size: 11.5px; letter-spacing: 0.09em;
  text-transform: uppercase; color: var(--muted); margin-bottom: 4px;
}
.key-figure dd {
  margin: 0; font-family: var(--mono); font-variant-numeric: tabular-nums;
  font-size: 24px; color: var(--accent); line-height: 1.2;
}

/* ---------- layout ---------- */

.layout { display: block; padding-top: 8px; }

.toc { margin: 18px 0; }
.toc-disclosure { font-family: var(--sans); }
.toc-disclosure summary {
  cursor: pointer; font-weight: 600; font-size: 15px; padding: 8px 0;
  list-style-position: inside;
}
.toc-list { list-style: none; margin: 8px 0 0; padding: 0; }
.toc-list a {
  display: block; padding: 3px 0; text-decoration: none; color: var(--muted);
  font-size: 14.5px; border-left: 3px solid transparent; padding-left: 10px;
}
.toc-list a:hover { color: var(--ink); }
.toc-list a.active { color: var(--accent); border-left-color: var(--accent); font-weight: 600; }
.toc-num {
  display: inline-block; min-width: 22px; font-family: var(--mono);
  font-size: 12.5px; color: var(--muted);
}
.toc-list a.active .toc-num { color: var(--accent); }

@media (min-width: 1100px) {
  .layout { display: grid; grid-template-columns: 250px minmax(0, 1fr); gap: 48px; }
  .toc { margin: 0; position: sticky; top: 24px; align-self: start; max-height: calc(100vh - 48px); overflow-y: auto; }
  .toc-disclosure > summary { display: none; }
  .toc-disclosure[open] .toc-list, .toc-disclosure .toc-list { display: block; }
  .toc-list { margin-top: 34px; }
  .toc-list a { padding: 4px 0 4px 10px; }
}

main { min-width: 0; }

/* ---------- sections ---------- */

section { max-width: 760px; margin: 0; padding: 44px 0 8px; }
section:has(.panel) { max-width: 1000px; }
section > p, section > ul, section > h3 { max-width: 760px; }

h2 {
  font-size: 27px; font-weight: 700; line-height: 1.25;
  border-top: 1px solid var(--rule); padding-top: 18px; margin: 0 0 14px;
  scroll-margin-top: 12px;
}
.sec-num {
  font-family: var(--mono); font-weight: 500; color: var(--accent);
  margin-right: 14px; font-size: 22px;
}
h3 {
  font-family: var(--sans); font-size: 16px; font-weight: 600;
  margin: 26px 0 8px; color: var(--ink);
}
.source-line { font-family: var(--sans); font-size: 14px; color: var(--muted); }
.section-lede { font-style: italic; color: var(--muted); }

/* ---------- tables (booktabs) ---------- */

.table-scroll { overflow-x: auto; max-width: 100%; margin: 10px 0; }
table {
  border-collapse: collapse; width: 100%; font-family: var(--sans);
  font-size: 14px; line-height: 1.45; border-top: 2px solid var(--ink);
  border-bottom: 2px solid var(--ink); min-width: 480px;
}
caption { text-align: left; font-size: 13px; color: var(--muted); padding-bottom: 6px; }
th, td { padding: 6px 12px 6px 0; text-align: left; vertical-align: top; }
thead th { border-bottom: 1px solid var(--ink); font-weight: 600; font-size: 13px; }
tbody tr { border-bottom: 0.5px solid var(--rule); }
tbody tr.subtotal td { border-top: 1px solid var(--muted); font-weight: 600; }
tbody tr.total td { border-top: 2px solid var(--ink); font-weight: 600; }
td.num, th.num { text-align: right; font-family: var(--mono); font-variant-numeric: tabular-nums; font-size: 13.5px; }
td .frac-note { display: block; font-size: 11.5px; color: var(--muted); font-family: var(--mono); }
tbody tr.hl td { background: var(--accent-soft); }

/* ---------- panels & controls ---------- */

.panel {
  background: var(--panel); border: 1px solid var(--rule); border-radius: 4px;
  padding: 18px 20px; margin: 14px 0; max-width: 1000px;
}

.controls-row {
  display: flex; flex-wrap: wrap; gap: 14px; align-items: flex-end;
  margin: 10px 0; font-family: var(--sans);
}
.control { display: flex; flex-direction: column; gap: 4px; }
.control label, .control > span:first-child {
  font-size: 11.5px; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--muted); font-weight: 600;
}
select, input[type="number"], input[type="text"] {
  font-family: var(--sans); font-size: 14.5px; color: var(--ink);
  background: var(--paper); border: 1px solid var(--muted); border-radius: 3px;
  padding: 5px 8px; max-width: 100%;
}
select:focus-visible, input:focus-visible, button:focus-visible, summary:focus-visible, a:focus-visible {
  outline: 2px solid var(--focus); outline-offset: 2px;
}
input[type="checkbox"] { accent-color: var(--accent); width: 16px; height: 16px; }
input[type="range"] { accent-color: var(--accent); }

.btn {
  font-family: var(--sans); font-size: 13.5px; font-weight: 600;
  background: var(--paper); color: var(--ink); border: 1px solid var(--ink);
  border-radius: 3px; padding: 6px 14px; cursor: pointer;
}
.btn:hover { background: var(--chip); }
.btn-quiet { border-color: var(--muted); color: var(--muted); }
.btn-small { padding: 3px 9px; font-size: 12.5px; }
.btn[disabled] { opacity: 0.45; cursor: default; }

/* event builder */

.preset-row { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
.event-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 18px; }
.event-def { border: 1px solid var(--rule); border-radius: 4px; padding: 12px 14px; background: var(--paper); }
.event-def h4 { margin: 0 0 4px; font-family: var(--serif); font-size: 17px; }
.event-def .ev-desc { font-family: var(--sans); font-size: 13px; color: var(--muted); min-height: 20px; margin-bottom: 8px; }
.event-def .control { margin-bottom: 8px; }
.event-def select { width: 100%; }
.event-toggle { margin: 16px 0 4px; font-family: var(--sans); font-size: 14.5px; }
#cControls { margin-top: 10px; }

.event-output { margin-top: 16px; }
.count-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 10px; margin: 12px 0 6px;
}
.count-cell { border-top: 2px solid var(--rule); padding-top: 6px; }
.count-cell .cc-label {
  font-family: var(--sans); font-size: 12px; letter-spacing: 0.02em; color: var(--muted);
}
.count-cell .cc-value { font-family: var(--mono); font-size: 21px; font-variant-numeric: tabular-nums; }

.math-out { margin: 12px 0; }
.math-out .katex-display { margin: 8px 0; overflow-x: auto; overflow-y: hidden; padding: 2px 0; }
.math-line { margin: 6px 0; overflow-x: auto; overflow-y: hidden; max-width: 100%; }

.event-extra { display: grid; grid-template-columns: 1fr; gap: 18px; margin-top: 14px; }
@media (min-width: 900px) { .event-extra { grid-template-columns: 1fr 320px; } }

.verdict {
  border-left: 3px solid var(--accent); padding: 6px 0 6px 14px; margin: 12px 0;
  font-family: var(--sans); font-size: 14.5px; max-width: 70ch;
}
.verdict .v-title { font-weight: 600; }
.verdict.ok { border-left-color: var(--survived); }
.verdict.no { border-left-color: var(--died); }
.verdict p { margin: 4px 0; }

.note-box {
  border-left: 3px solid var(--accent); padding: 4px 0 4px 14px; margin: 18px 0;
  max-width: 760px;
}
.note-box p { margin: 6px 0; }

.muted-line { font-family: var(--sans); font-size: 13.5px; color: var(--muted); margin: 6px 0; }

/* figures & charts */

.fig { margin: 18px 0; max-width: 1000px; }
figure.fig { margin-left: 0; }
.figure-caption {
  font-family: var(--sans); font-size: 13px; color: var(--muted); margin: 6px 0 0;
}
svg.chart { display: block; width: 100%; height: auto; }
svg.chart text { font-family: var(--sans); font-size: 12px; fill: var(--muted); }
svg.chart text.val { font-family: var(--mono); font-variant-numeric: tabular-nums; fill: var(--ink); }
svg.chart .axis { stroke: var(--ink); stroke-width: 1; }
svg.chart .guide { stroke: var(--rule); stroke-width: 0.7; }
svg.chart .bar { fill: var(--survived); }
svg.chart .bar.alt { fill: var(--accent); }
svg.chart .bar.dim { fill: var(--rule); }
svg.chart .pt { fill: var(--accent); opacity: 0.32; }
svg.chart .line { stroke: var(--died); stroke-width: 2; fill: none; }
svg.chart .frame { fill: none; stroke: var(--rule); }

/* verdict ticks */
.tick { font-family: var(--sans); font-weight: 600; }
.tick.yes { color: var(--survived); }
.tick.no { color: var(--died); }

/* lifeboat rows */

.boat-row {
  display: flex; flex-wrap: wrap; gap: 10px; align-items: flex-end;
  padding: 8px 0; border-bottom: 0.5px solid var(--rule); font-family: var(--sans);
}
.boat-row .control { min-width: 130px; }
.boat-row .boat-p { font-family: var(--mono); font-size: 13.5px; min-width: 190px; }
.boat-row .boat-p .nodata { color: var(--died); }
.boat-row .row-num { font-family: var(--mono); color: var(--muted); width: 22px; padding-bottom: 7px; }

/* quiz */

.quiz-score { font-family: var(--mono); font-size: 14px; color: var(--muted); align-self: center; }
#quizBox { font-family: var(--sans); font-size: 15.5px; margin: 10px 0; }
#quizBox .q-text { margin: 4px 0; }
#quizResult { font-family: var(--sans); font-size: 15px; margin: 8px 0; font-weight: 600; }
#quizResult.ok { color: var(--survived); }
#quizResult.no { color: var(--died); }
#quizSolution { margin: 8px 0; }

/* formula reference */

.ref-group { margin: 14px 0; max-width: 760px; }
.ref-group h3 { margin-bottom: 4px; }
.ref-item {
  display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr); gap: 14px;
  border-bottom: 0.5px solid var(--rule); padding: 9px 0; align-items: baseline;
}
@media (max-width: 700px) { .ref-item { grid-template-columns: 1fr; gap: 2px; } }
.ref-item .ref-math { overflow-x: auto; }
.ref-item .ref-note { font-family: var(--sans); font-size: 13.5px; color: var(--muted); }
.ref-item .ref-note a { white-space: nowrap; }

/* inline tex spans */
.tex .katex { font-size: 1.02em; }

/* footer */

.site-footer { border-top: 2px solid var(--ink); margin-top: 56px; padding: 20px 0 40px; }
.site-footer p { font-family: var(--sans); font-size: 13.5px; color: var(--muted); max-width: 76ch; margin: 0; }

/* print */

@media print {
  .toc, .controls-row, .preset-row, .event-toggle, #quizAnswerRow, .skip-link { display: none !important; }
  body { font-size: 11pt; }
  .panel { border: none; padding: 0; }
  section { padding-top: 18px; }
  a { color: inherit; text-decoration: none; }
}

/* long display formulas scroll inside their own box instead of widening the page */
.katex-display { overflow-x: auto; overflow-y: hidden; max-width: 100%; padding: 2px 0; }
.ref-math { overflow-x: auto; overflow-y: hidden; max-width: 100%; }

/* ---------- toggle-button groups (replace the selects) ---------- */

.chip-source { display: none !important; }
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chip {
  font-family: var(--sans); font-size: 13.5px; line-height: 1.2; color: var(--ink);
  background: var(--paper); border: 1px solid var(--rule); border-radius: 3px;
  padding: 6px 10px; cursor: pointer; min-height: 32px;
  transition: background-color 0.12s ease, border-color 0.12s ease, color 0.12s ease;
}
.chip:hover { border-color: var(--muted); }
.chip.on { background: var(--accent); border-color: var(--accent); color: var(--paper); font-weight: 600; }
.chip:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
.control-chips { gap: 6px; }
.event-def .control-chips { margin-bottom: 12px; }
.boat-row .control-chips { min-width: 0; }

/* ---------- percentage readouts ---------- */

.pct-grid {
  display: grid; grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px; margin: 14px 0 10px;
}
.pct-cell { border: 1px solid var(--rule); border-radius: 4px; padding: 10px 12px; background: var(--paper); }
.pct-cell.strong { border-left: 3px solid var(--accent); }
.pc-label { font-family: var(--sans); font-size: 12.5px; color: var(--muted); }
.pc-value { font-family: var(--mono); font-size: 26px; line-height: 1.25; color: var(--accent); font-variant-numeric: tabular-nums; }
.pc-frac, .pc-target { font-family: var(--mono); font-size: 12.5px; color: var(--muted); }
.pc-target { margin-top: 2px; color: var(--ink); }

@media (max-width: 700px) {
  .pct-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .pc-value { font-size: 22px; }
}

@media (prefers-reduced-motion: reduce) { .chip { transition: none; } }
@media print { .chips { display: none !important; } }

@media (max-width: 600px) {
  .katex-display { font-size: 0.8em; }
  .math-line { margin: 2px 0; }
}