/* AI Proved What? — one stylesheet for the whole site.
   Colors match the videos: the same ink background, with blue for links
   and gold reserved for the proof box (∎). */

:root {
  --ink: #0e1117;
  --raised: #151a23;
  --rule: #262c37;
  --paper: #ece9e1;
  --soft: #cdcac2;
  --dim: #9aa0aa;
  --blue: #58c4dd;
  --gold: #ffd84d;
  --red: #fc6255;
  --serif: "STIX Two Text", "STIX Two", "Times New Roman", Times, serif;
  --measure: 36rem;
  --wide: 58rem;
  color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }

html {
  background: var(--ink);
  color: var(--paper);
  font-family: var(--serif);
  font-size: 112.5%;
  line-height: 1.62;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--ink);
  font-variant-numeric: lining-nums;
}

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

a {
  color: var(--blue);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
}
a:hover { text-decoration-thickness: 2px; }

:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
  border-radius: 2px;
}

.skip {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--paper);
  color: var(--ink);
  padding: 0.5rem 0.9rem;
  z-index: 10;
}
.skip:focus { left: 1rem; top: 1rem; }

.wrap {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 0 1rem;
}
@media (min-width: 40rem) {
  .wrap { padding: 0 2rem; }
}

.measure { max-width: var(--measure); }

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

.site-head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  padding: 1.1rem 0;
  border-bottom: 1px solid var(--rule);
}

.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  color: var(--paper);
  text-decoration: none;
  font-weight: 600;
  font-size: 1.08rem;
  letter-spacing: 0.005em;
}
.wordmark .mark {
  width: 0.95em;
  height: 1.45em;
  color: var(--paper);
  flex: none;
}

.site-nav ul {
  display: flex;
  gap: 1.25rem;
  margin: 0;
  padding: 0;
  list-style: none;
}
.site-nav a {
  color: var(--soft);
  text-decoration: none;
}
.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: var(--paper);
  text-decoration: underline;
  text-decoration-thickness: 1px;
}

/* ---------- type ---------- */

main { padding: 2.75rem 0 1rem; }

h1, h2, h3 {
  font-weight: 600;
  text-wrap: balance;
}

h1 {
  font-size: clamp(2.1rem, 5.4vw, 3.5rem);
  line-height: 1.08;
  letter-spacing: -0.012em;
  margin: 0 0 1.1rem;
}

h2 {
  font-size: 1.5rem;
  line-height: 1.25;
  margin: 3rem 0 0.9rem;
}

h3 {
  font-size: 1.12rem;
  margin: 1.6rem 0 0.4rem;
}

p { margin: 0 0 1rem; }

.lede {
  font-size: 1.2rem;
  line-height: 1.55;
  color: var(--soft);
  max-width: 34rem;
}

.meta {
  font-style: italic;
  color: var(--dim);
  margin: 0 0 0.6rem;
}

.subtitle {
  font-size: 1.25rem;
  color: var(--soft);
  margin: -0.4rem 0 1.8rem;
  font-style: italic;
}

.num { font-variant-numeric: lining-nums tabular-nums; }

/* ---------- the player ---------- */

.player {
  position: relative;
  aspect-ratio: 16 / 9;
  margin: 2rem 0 0.6rem;
  background: #000;
  border: 1px solid var(--rule);
  border-radius: 4px;
  overflow: hidden;
}
.player > a,
.player iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: 0;
}
.player img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.play {
  position: absolute;
  right: 3.5%;
  top: 6%;
  width: clamp(2.9rem, 8vw, 4.4rem);
  height: clamp(2.9rem, 8vw, 4.4rem);
  border-radius: 50%;
  background: rgba(14, 17, 23, 0.82);
  border: 2px solid var(--paper);
}
.play::after {
  content: "";
  position: absolute;
  inset: 0;
  margin: auto;
  width: 36%;
  height: 40%;
  transform: translateX(10%);
  background: var(--paper);
  clip-path: polygon(0 0, 100% 50%, 0 100%);
}
.player > a:hover .play,
.player > a:focus-visible .play { border-color: var(--gold); }
.player > a:hover .play::after,
.player > a:focus-visible .play::after { background: var(--gold); }

.player-caption {
  color: var(--dim);
  font-size: 0.95rem;
  margin: 0 0 2rem;
}

/* ---------- the ledger: ∎ means checked, □ means not yet ---------- */

.ledger {
  margin: 1rem 0 0.7rem;
  border-top: 1px solid var(--rule);
}
.ledger-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.2rem 1.5rem;
  align-items: baseline;
  padding: 0.7rem 0;
  border-bottom: 1px solid var(--rule);
}
.ledger dt {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
}
.ledger dd {
  margin: 0;
  color: var(--dim);
  text-align: right;
}
.ledger-row.is-done dd { color: var(--soft); }
.ledger-row.is-withdrawn dt,
.ledger-row.is-withdrawn dd { color: var(--red); }

.box {
  display: inline-block;
  flex: none;
  width: 0.7em;
  height: 0.7em;
  border: 2px solid var(--dim);
  transform: translateY(0.04em);
}
.is-done .box {
  background: var(--gold);
  border-color: var(--gold);
}
.is-withdrawn .box {
  background: var(--red);
  border-color: var(--red);
}

.ledger-note {
  color: var(--dim);
  font-style: italic;
  font-size: 0.95rem;
}

@media (max-width: 30rem) {
  .ledger-row { grid-template-columns: 1fr; }
  .ledger dd { text-align: left; padding-left: 1.45em; }
}

/* ---------- episode list ---------- */

.episodes {
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
  border-top: 1px solid var(--rule);
}
.episodes li { border-bottom: 1px solid var(--rule); }
.episodes a {
  display: grid;
  grid-template-columns: 3.2rem 1fr;
  gap: 0 1rem;
  padding: 1.1rem 0;
  color: var(--paper);
  text-decoration: none;
}
.episodes a:hover .ep-title { text-decoration: underline; text-decoration-thickness: 1px; }
.ep-num { color: var(--dim); }
.ep-title { font-size: 1.22rem; font-weight: 600; display: block; }
.ep-sub { color: var(--soft); font-style: italic; display: block; }
.ep-facts {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem 1rem;
  margin-top: 0.35rem;
  color: var(--dim);
  font-size: 0.95rem;
}
.mini {
  display: inline-flex;
  gap: 0.28rem;
}
.mini .box { width: 0.62em; height: 0.62em; }

/* ---------- chapters ---------- */

.chapters {
  list-style: none;
  margin: 0;
  padding: 0;
  columns: 1;
}
@media (min-width: 44rem) {
  .chapters { columns: 2; column-gap: 2.5rem; }
}
.chapters li { break-inside: avoid; }
.chapters a {
  display: grid;
  grid-template-columns: 3.1rem 1fr;
  gap: 0.75rem;
  padding: 0.3rem 0;
  color: var(--paper);
  text-decoration: none;
}
.chapters a:hover span:last-child { text-decoration: underline; text-decoration-thickness: 1px; }
.chapters .t { color: var(--blue); font-variant-numeric: tabular-nums lining-nums; }

/* ---------- steps and prose ---------- */

.steps {
  margin: 0;
  padding-left: 1.4rem;
}
.steps li { margin-bottom: 0.8rem; padding-left: 0.3rem; }
.steps li::marker { color: var(--dim); }

.sources { padding-left: 1.2rem; }
.sources li { margin-bottom: 0.45rem; }

/* ---------- transcript ---------- */

details.transcript {
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  padding: 0.9rem 0;
}
details.transcript summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 1.12rem;
}
details.transcript summary::marker { color: var(--dim); }
.transcript h3 { color: var(--soft); }
.transcript h3 .t { color: var(--blue); font-weight: 400; margin-right: 0.6rem; }

/* ---------- footer ---------- */

.site-foot {
  margin-top: 4rem;
  padding: 1.6rem 0 3rem;
  border-top: 1px solid var(--rule);
  color: var(--dim);
  font-size: 0.95rem;
}
.site-foot p { max-width: 40rem; }
.site-foot a { color: var(--soft); }
.foot-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.25rem;
  margin: 0 0 0.8rem;
  padding: 0;
  list-style: none;
}
.box.on {
  background: var(--gold);
  border-color: var(--gold);
}