:root {
  color-scheme: light;
  --bg: #faf5ea;
  --bg-raised: #ffffff;
  --bg-sunken: #f0e6d2;
  --ink: #241a10;
  --ink-soft: #4a3b28;
  --ink-mute: #6b5c46;
  --line: #ddcda9;
  --accent: #a8471c;
  --accent-ink: #ffffff;
  --accent-soft: #f3ddc9;
  --gold: #8a6a1f;
  --tag-fact: #2f5d3a;
  --tag-fact-bg: #e2ecdd;
  --tag-hyp: #7a4a1f;
  --tag-hyp-bg: #f6e6cf;
  --tag-mem: #5a3c78;
  --tag-mem-bg: #ece2f5;
  --focus: #a8471c;
  --shadow: 0 10px 30px -18px rgba(36, 26, 16, 0.4);
}
:root:not([data-theme="light"]) {
  @media (prefers-color-scheme: dark) {
    color-scheme: dark;
    --bg: #17130e;
    --bg-raised: #221b13;
    --bg-sunken: #0f0c08;
    --ink: #f3ead9;
    --ink-soft: #d8c9ac;
    --ink-mute: #ab9a7d;
    --line: #3a2f21;
    --accent: #e2803f;
    --accent-ink: #1a1208;
    --accent-soft: #3a2a17;
    --gold: #d9b25c;
    --tag-fact: #a9d3ae;
    --tag-fact-bg: #223626;
    --tag-hyp: #e8c99a;
    --tag-hyp-bg: #3a2c17;
    --tag-mem: #d3bdec;
    --tag-mem-bg: #2c2038;
    --focus: #e2803f;
    --shadow: 0 10px 34px -16px rgba(0, 0, 0, 0.65);
  }
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #17130e;
  --bg-raised: #221b13;
  --bg-sunken: #0f0c08;
  --ink: #f3ead9;
  --ink-soft: #d8c9ac;
  --ink-mute: #ab9a7d;
  --line: #3a2f21;
  --accent: #e2803f;
  --accent-ink: #1a1208;
  --accent-soft: #3a2a17;
  --gold: #d9b25c;
  --tag-fact: #a9d3ae;
  --tag-fact-bg: #223626;
  --tag-hyp: #e8c99a;
  --tag-hyp-bg: #3a2c17;
  --tag-mem: #d3bdec;
  --tag-mem-bg: #2c2038;
  --focus: #e2803f;
  --shadow: 0 10px 34px -16px rgba(0, 0, 0, 0.65);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, .display {
  font-family: Georgia, "Iowan Old Style", "Palatino Linotype", serif;
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--ink);
}
a { color: var(--accent); }
a:focus-visible, button:focus-visible, .icon-btn:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
img { max-width: 100%; }
.container { max-width: 1180px; margin: 0 auto; padding: 0 20px; }
.prose { max-width: 700px; }
.wide { max-width: 980px; }

/* ---- topbar ---- */
.topbar {
  position: sticky; top: 0; z-index: 40;
  display: flex; align-items: center; gap: 14px;
  height: 52px; padding: 0 16px;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.topbar .home { font-weight: 700; color: var(--ink); text-decoration: none; font-size: 0.92rem; white-space: nowrap; }
.topnav { display: flex; gap: 4px; overflow-x: auto; scrollbar-width: none; -ms-overflow-style: none; }
.topnav::-webkit-scrollbar { display: none; }
.topnav a {
  white-space: nowrap; text-decoration: none; color: var(--ink-mute);
  font-size: 0.85rem; padding: 6px 10px; border-radius: 999px;
}
.topnav a[aria-current="true"] { color: var(--accent-ink); background: var(--accent); }
.spacer { flex: 1 1 auto; }
.chip {
  white-space: nowrap; text-decoration: none; color: var(--ink-soft);
  border: 1px solid var(--line); border-radius: 999px; padding: 5px 12px; font-size: 0.82rem;
}
.icon-btn {
  display: inline-flex; align-items: center; justify-content: center;
  width: 32px; height: 32px; border-radius: 999px; border: 1px solid var(--line);
  background: var(--bg-raised); color: var(--ink); cursor: pointer; flex: 0 0 auto;
}
.icon-btn svg[hidden] { display: none; }

/* ---- reading rail ---- */
.rail {
  position: fixed; top: 96px; right: 20px; width: 160px;
  display: none; font-size: 0.8rem; color: var(--ink-mute);
}
.rail a { display: block; text-decoration: none; color: var(--ink-mute); padding: 4px 0 4px 10px; border-left: 2px solid var(--line); }
.rail a[aria-current="true"] { color: var(--accent); border-left-color: var(--accent); font-weight: 600; }
@media (min-width: 1240px) { .rail { display: block; } }

/* ---- hero ---- */
.hero { padding: 56px 0 40px; }
.kicker { color: var(--gold); font-weight: 700; letter-spacing: 0.06em; text-transform: uppercase; font-size: 0.78rem; margin: 0 0 12px; }
.hero h1 { font-size: clamp(2rem, 5.2vw, 3.4rem); margin: 0 0 18px; }
.deck { font-size: 1.18rem; color: var(--ink-soft); max-width: 640px; margin: 0 0 22px; }
.hero-meta { display: flex; flex-wrap: wrap; gap: 10px 20px; color: var(--ink-mute); font-size: 0.86rem; }

section { padding: 52px 0; scroll-margin-top: 64px; border-top: 1px solid var(--line); }
section:first-of-type { border-top: none; }
.eyebrow { color: var(--gold); font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; font-size: 0.76rem; margin: 0 0 10px; }
h2 { font-size: clamp(1.5rem, 3.2vw, 2.1rem); margin: 0 0 16px; }
h3 { font-size: 1.2rem; margin: 26px 0 10px; }
p { margin: 0 0 16px; }
.lede { font-size: 1.08rem; color: var(--ink-soft); }
.limit { font-size: 0.88rem; color: var(--ink-mute); border-left: 3px solid var(--line); padding-left: 12px; margin: 18px 0; }

/* ---- quote / artefact cards ---- */
.artefact {
  background: var(--bg-raised); border: 1px solid var(--line); border-radius: 14px;
  padding: 22px 24px; box-shadow: var(--shadow); margin: 22px 0;
}
.artefact .date { color: var(--gold); font-weight: 700; font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.04em; }
.artefact blockquote { margin: 10px 0 8px; font-family: Georgia, serif; font-size: 1.22rem; line-height: 1.4; }
.artefact cite { color: var(--ink-mute); font-size: 0.84rem; font-style: normal; }
.artefact cite a { color: var(--ink-mute); }

/* ---- memory vs archive ---- */
.split { display: grid; grid-template-columns: 1fr; gap: 14px; margin: 20px 0; }
@media (min-width: 700px) { .split { grid-template-columns: 1fr 1fr; } }
.split > div { border-radius: 14px; padding: 20px; border: 1px solid var(--line); }
.split .memory { background: var(--tag-mem-bg); }
.split .archive { background: var(--tag-fact-bg); }
.split h4 { margin: 0 0 8px; font-size: 0.86rem; text-transform: uppercase; letter-spacing: 0.05em; }
.split .memory h4 { color: var(--tag-mem); }
.split .archive h4 { color: var(--tag-fact); }
.split ul { margin: 0; padding-left: 18px; }
.split li { margin-bottom: 6px; }

/* ---- tag badges ---- */
.tag { display: inline-block; font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.04em; padding: 3px 8px; border-radius: 6px; margin-right: 6px; }
.tag-fact { color: var(--tag-fact); background: var(--tag-fact-bg); }
.tag-hyp { color: var(--tag-hyp); background: var(--tag-hyp-bg); }
.tag-mem { color: var(--tag-mem); background: var(--tag-mem-bg); }

/* ---- machine lineage ---- */
.lineage { list-style: none; margin: 24px 0; padding: 0; border-left: 2px solid var(--line); }
.lineage li { position: relative; padding: 2px 0 26px 26px; }
.lineage li::before { content: ""; position: absolute; left: -6px; top: 5px; width: 10px; height: 10px; border-radius: 50%; background: var(--accent); }
.lineage .lyear { font-weight: 700; color: var(--gold); font-size: 0.85rem; }
.lineage .ltitle { font-weight: 600; margin: 2px 0 2px; }
.lineage .ldesc { color: var(--ink-soft); font-size: 0.94rem; }

/* ---- process diagram ---- */
.process { margin: 24px 0; }
.process svg { width: 100%; height: auto; }
.process text { fill: var(--ink); font-family: -apple-system, sans-serif; }
.process .lbl { font-size: 12px; fill: var(--ink-mute); }
.process .val { font-size: 13px; font-weight: 700; }
.process .box { fill: var(--bg-raised); stroke: var(--line); }
.process .arrow { stroke: var(--accent); stroke-width: 2; fill: none; marker-end: url(#pf-arrow); }

/* ---- hypothesis line ---- */
.hyp-line { stroke: var(--tag-hyp); stroke-width: 2; stroke-dasharray: 5 5; fill: none; }

/* ---- table ---- */
.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: 12px; }
table.data { width: 100%; border-collapse: collapse; font-size: 0.9rem; min-width: 560px; }
table.data th, table.data td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--line); }
table.data th { background: var(--bg-sunken); font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.03em; color: var(--ink-mute); }
table.data tr:last-child td { border-bottom: none; }
.table-note { font-size: 0.85rem; color: var(--ink-mute); margin-top: 10px; }
.load-more { margin-top: 14px; }
button.btn {
  font: inherit; font-size: 0.88rem; font-weight: 600; color: var(--accent-ink);
  background: var(--accent); border: none; border-radius: 999px; padding: 9px 18px; cursor: pointer;
}
button.btn:hover { filter: brightness(1.08); }
tr[hidden] { display: none; }

/* ---- regimes chart ---- */
.regimes { display: grid; grid-template-columns: 1fr; gap: 12px; margin: 24px 0; }
@media (min-width: 760px) { .regimes { grid-template-columns: repeat(4, 1fr); } }
.regime { border-radius: 14px; padding: 18px; border: 1px solid var(--line); background: var(--bg-raised); }
.regime .r-years { font-weight: 700; color: var(--gold); font-size: 0.82rem; }
.regime h4 { margin: 6px 0 8px; font-size: 1rem; }
.regime p { font-size: 0.88rem; color: var(--ink-soft); margin: 0; }

/* ---- 1971 artefact photo ---- */
.artefact-photo { margin: 18px 0; border-radius: 12px; overflow: hidden; border: 1px solid var(--line); background: var(--bg-sunken); }
.artefact-photo img { display: block; width: 100%; height: auto; }
.artefact-photo figcaption { padding: 10px 14px; font-size: 0.82rem; color: var(--ink-mute); }

/* ---- contradiction callout ---- */
.callout {
  border-radius: 14px; padding: 20px 22px; margin: 22px 0;
  background: var(--tag-hyp-bg); border: 1px solid color-mix(in srgb, var(--tag-hyp) 40%, transparent);
}
.callout .eyebrow { color: var(--tag-hyp); }
.callout .figures { display: flex; gap: 22px; flex-wrap: wrap; margin: 12px 0; }
.callout .figure b { display: block; font-size: 1.5rem; font-family: Georgia, serif; }
.callout .figure span { font-size: 0.82rem; color: var(--ink-mute); }

/* ---- footer ---- */
footer { border-top: 1px solid var(--line); padding: 40px 0 60px; color: var(--ink-mute); font-size: 0.86rem; }
footer a { color: var(--ink-mute); }
footer .flinks { display: flex; flex-wrap: wrap; gap: 16px; margin-bottom: 14px; }
footer .fmeta { display: flex; flex-wrap: wrap; gap: 14px; }

.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

.bag-figure { text-align: center; margin: 30px 0; }
.bag-figure svg { max-width: 260px; }
.figure-cap { font-size: 0.85rem; color: var(--ink-mute); margin-top: 8px; }

.grid-2 { display: grid; grid-template-columns: 1fr; gap: 20px; }
@media (min-width: 760px) { .grid-2 { grid-template-columns: 1fr 1fr; } }

.source-list { columns: 1; font-size: 0.85rem; color: var(--ink-mute); }
@media (min-width: 760px) { .source-list { columns: 2; gap: 30px; } }
.source-list li { break-inside: avoid; margin-bottom: 8px; }