/* ============================================================
   Contrastive Discovery — project page styles
   One file, no build step. Edit the variables in :root to change
   colors, fonts, and column widths; everything else follows.
   ============================================================ */

:root {
  /* Colors */
  --bg: #fbfaf7;          /* page background (warm off-white) */
  --surface: #ffffff;     /* cards, figure panels */
  --ink: #1d1b18;         /* body text */
  --muted: #5f5a53;       /* captions, secondary text */
  --line: #e6e1d8;        /* hairline borders */
  --accent: #1f5fa8;      /* brand blue ("resolved") */
  --accent-tint: #e9f1fb; /* pale blue backgrounds */
  --red: #c8412c;         /* "rejected" red, used sparingly */

  /* Type */
  --serif: "Iowan Old Style", "Charter", "Palatino Linotype", Palatino, Georgia, serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;

  /* Layout */
  --column: 880px;        /* text column */
  --column-wide: 1080px;  /* wide figures */
  --radius: 12px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

img { max-width: 100%; height: auto; display: block; }

h1, h2, h3 { font-family: var(--serif); font-weight: 600; line-height: 1.2; margin: 0; }
h2 { font-size: 1.9rem; margin-bottom: .6rem; }
h3 { font-size: 1.15rem; margin-bottom: .4rem; }
p { margin: 0 0 1rem; }
strong { font-weight: 600; }

.wrap { max-width: var(--column); margin: 0 auto; padding: 0 24px; }
.wrap.wide { max-width: var(--column-wide); }

/* Inline math written in plain HTML */
.math { font-family: var(--serif); font-style: italic; white-space: nowrap; }
.math sub, .math sup { font-style: normal; font-size: .75em; }

/* ---------- Hero ---------- */
.hero { text-align: center; padding: 72px 0 40px; }

.eyebrow {
  font-family: var(--mono);
  font-size: .8rem;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 20px;
}

.hero h1 {
  font-size: clamp(2.2rem, 1.2rem + 4vw, 3.6rem);
  letter-spacing: -.01em;
  color: var(--accent);
}
.hero .subtitle {
  font-family: var(--serif);
  font-size: clamp(1.25rem, 1rem + 1.4vw, 1.7rem);
  color: var(--ink);
  margin: 10px auto 22px;
  max-width: 44ch;
  line-height: 1.3;
}
.hero .dek {
  font-size: 1.15rem;
  color: var(--muted);
  max-width: 60ch;
  margin: 0 auto 28px;
}

.authors { font-size: 1.05rem; margin-bottom: 4px; }
.authors a { color: var(--ink); }
.authors a:hover { color: var(--accent); }
.affil { color: var(--muted); font-size: .95rem; margin-bottom: 26px; }
.affil small { display: block; font-size: .85rem; margin-top: 2px; }

.buttons { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 18px;
  border: 1.5px solid var(--ink);
  border-radius: 999px;
  color: var(--ink);
  font-weight: 600;
  font-size: .95rem;
  background: var(--surface);
  transition: background .15s, color .15s;
}
.btn:hover { background: var(--ink); color: #fff; text-decoration: none; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.primary:hover { background: #17497f; border-color: #17497f; }
.btn svg { width: 18px; height: 18px; fill: currentColor; }

/* ---------- Teaser figure ---------- */
.teaser { padding: 16px 0 8px; }

/* ---------- TL;DR + headline numbers ---------- */
.tldr {
  background: var(--accent-tint);
  border: 1px solid #cfdff2;
  border-radius: var(--radius);
  padding: 22px 26px;
  margin: 28px 0 24px;
  font-size: 1.05rem;
}
.tldr .label {
  font-family: var(--mono); font-size: .75rem; letter-spacing: .1em;
  text-transform: uppercase; color: var(--accent); margin-bottom: 8px;
}
.tldr p:last-child { margin-bottom: 0; }

.stats {
  list-style: none; padding: 0; margin: 0 0 8px;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px;
}
.stat {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 18px 16px;
}
.stat .num { font-family: var(--serif); font-size: 2.3rem; line-height: 1; color: var(--accent); }
.stat .num.red { color: var(--red); }
.stat .lbl { font-size: .9rem; color: var(--muted); margin-top: 8px; line-height: 1.4; }

/* ---------- Sections ---------- */
.section { padding: 56px 0 8px; }
.section.tint { background: var(--surface); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); padding-bottom: 48px; }
.kicker {
  font-family: var(--mono); font-size: .78rem; letter-spacing: .1em;
  text-transform: uppercase; color: var(--accent); margin-bottom: 10px;
}
.lead { font-size: 1.1rem; max-width: 66ch; }

/* Figures */
.fig { margin: 24px 0 8px; }
.fig .panel {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px;
}
.fig img { margin: 0 auto; }
.fig figcaption { color: var(--muted); font-size: .95rem; line-height: 1.5; margin: 12px 4px 0; max-width: 90ch; }
.fig figcaption b { color: var(--ink); }

/* Narrow figure with its caption alongside (stacks on small screens) */
.fig.side { display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr); gap: 24px; align-items: center; }
.fig.side figcaption { margin: 0; }

.section h2.sub { margin-top: 44px; }

/* "How it works" step cards */
.steps {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px;
  margin: 24px 0 20px;
}
.step {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px 20px 16px;
}
.step .n {
  display: inline-block; width: 28px; height: 28px; line-height: 28px; text-align: center;
  border-radius: 50%; background: var(--accent); color: #fff;
  font-family: var(--mono); font-size: .85rem; font-weight: 600; margin-bottom: 10px;
}
.step p { font-size: .95rem; color: var(--muted); margin: 0; }
.step p + p { margin-top: 8px; }

.note { font-size: .95rem; color: var(--muted); max-width: 70ch; }
h3.sub { font-size: 1.35rem; margin: 36px 0 6px; }

/* Example contrast-set table */
.examples {
  width: 100%; border-collapse: collapse; margin: 14px 0 28px;
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; font-size: .95rem;
}
.examples th, .examples td { text-align: left; vertical-align: top; padding: 14px 16px; border-top: 1px solid var(--line); }
.examples th {
  border-top: 0; font-family: var(--mono); font-weight: 600; font-size: .75rem;
  letter-spacing: .08em; text-transform: uppercase; color: var(--muted); background: var(--bg);
}
.examples th:nth-child(1) { width: 17%; }
.examples th:nth-child(2) { width: 37%; }
.examples .domain { font-family: var(--mono); font-size: .8rem; color: var(--muted); white-space: nowrap; }
.examples .q { font-family: var(--serif); font-size: 1.05rem; line-height: 1.35; }
.alts { list-style: none; margin: 0; padding: 0; counter-reset: h; }
.alts li { position: relative; padding-left: 40px; margin: 0 0 6px; counter-increment: h; }
.alts li:last-child { margin-bottom: 0; }
.alts li::before {
  content: "H" counter(h); position: absolute; left: 0; top: 3px;
  width: 30px; text-align: center; border-radius: 6px;
  background: var(--accent-tint); color: var(--accent);
  font-family: var(--mono); font-size: .72rem; font-weight: 600; line-height: 18px;
}

/* Compact evidence cards (validation section) */
.cards { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; margin-top: 22px; }
.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px 20px 16px;
}
.card p { font-size: .95rem; color: var(--muted); margin: 0; }

/* Takeaway quote */
.takeaway {
  font-family: var(--serif); font-size: 1.5rem; line-height: 1.35;
  text-align: center; max-width: 34ch; margin: 44px auto 0; color: var(--ink);
}

/* BibTeX */
.bibtex { position: relative; background: #1d1b18; color: #e9e5dd; border-radius: var(--radius); padding: 18px 20px; margin-top: 18px; overflow-x: auto; }
.bibtex pre { margin: 0; font-family: var(--mono); font-size: .85rem; line-height: 1.5; }
.bibtex button {
  position: absolute; top: 12px; right: 12px;
  background: transparent; color: #e9e5dd; border: 1px solid #5b5750; border-radius: 6px;
  font: 600 .8rem var(--sans); padding: 5px 10px; cursor: pointer;
}
.bibtex button:hover { background: var(--accent); border-color: var(--accent); }

footer { text-align: center; color: var(--muted); font-size: .9rem; padding: 48px 24px 60px; }

/* ---------- Responsive ---------- */
@media (max-width: 860px) {
  .stats { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: 1fr; }
  .fig.side { grid-template-columns: 1fr; gap: 0; }
  .fig.side figcaption { margin: 12px 4px 0; }
}
@media (max-width: 640px) {
  body { font-size: 16px; }
  /* Example table: each row becomes a stacked card */
  .examples thead { display: none; }
  .examples, .examples tbody, .examples tr, .examples td { display: block; }
  .examples td { padding: 4px 14px; border-top: 0; }
  .examples tr { padding: 12px 0; border-top: 1px solid var(--line); }
  .examples tr:first-child { border-top: 0; }
  .examples td:last-child { padding-top: 8px; }
  .hero { padding-top: 48px; }
  .section { padding-top: 44px; }
  .cards { grid-template-columns: 1fr; }
  .fig .panel { padding: 10px; }
  .tldr { padding: 18px; }
  .takeaway { font-size: 1.25rem; }
}