/* atlas of atlases — landing instrument
   self-contained, no build step, dark-mode-safe.
   theme: light by default, dark via prefers-color-scheme and a manual toggle. */

:root {
  --bg: #f7f8fa;
  --bg-elev: #ffffff;
  --bg-sunk: #eef1f5;
  --ink: #1a2230;
  --ink-soft: #4a5568;
  --ink-faint: #6c757d;
  --line: #d9dee5;
  --line-soft: #e6eaef;
  --accent: #1f6f8b;       /* delivered / teal */
  --accent-ink: #14505f;
  --promise: #6b7891;      /* declared / promise */
  --demand: #c1666b;       /* demand / warm */
  --flag: #d1495b;         /* gap flag / alarm */
  --up: #2a9d8f;
  --rung-existence: #c1666b;
  --rung-authority: #d99a4e;
  --rung-oversight: #4e8fa8;
  --rung-verifiability: #2a9d8f;
  --shadow: 0 1px 2px rgba(20,30,45,.06), 0 4px 14px rgba(20,30,45,.05);
  --radius: 12px;
  --maxw: 1180px;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0e1419;
    --bg-elev: #161d25;
    --bg-sunk: #11171d;
    --ink: #e6ebf1;
    --ink-soft: #aab4c0;
    --ink-faint: #7d8794;
    --line: #2a333d;
    --line-soft: #232b33;
    --accent: #5db4cf;
    --accent-ink: #9fd6e6;
    --promise: #9aa7b8;
    --demand: #e08b90;
    --flag: #f0707f;
    --up: #4fc4b4;
    --shadow: 0 1px 2px rgba(0,0,0,.4), 0 6px 20px rgba(0,0,0,.35);
  }
}

/* manual dark override (toggle) */
:root[data-theme="dark"] {
  --bg: #0e1419;
  --bg-elev: #161d25;
  --bg-sunk: #11171d;
  --ink: #e6ebf1;
  --ink-soft: #aab4c0;
  --ink-faint: #7d8794;
  --line: #2a333d;
  --line-soft: #232b33;
  --accent: #5db4cf;
  --accent-ink: #9fd6e6;
  --promise: #9aa7b8;
  --demand: #e08b90;
  --flag: #f0707f;
  --up: #4fc4b4;
  --shadow: 0 1px 2px rgba(0,0,0,.4), 0 6px 20px rgba(0,0,0,.35);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

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

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

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }

/* ---------- draft banner ---------- */
.draft-banner {
  background: var(--flag);
  color: #fff;
  text-align: center;
  font-size: .9rem;
  font-weight: 600;
  padding: 8px 16px;
  letter-spacing: .01em;
}
.draft-banner a { color: #fff; text-decoration: underline; }

/* ---------- top bar ---------- */
.topbar {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: saturate(140%) blur(8px);
  border-bottom: 1px solid var(--line);
}
.topbar .wrap {
  display: flex; align-items: center; gap: 16px;
  min-height: 56px; flex-wrap: wrap;
}
.brand { font-weight: 700; font-size: 1.02rem; letter-spacing: -.01em; }
.brand .dot { color: var(--accent); }
.topnav { display: flex; gap: 14px; margin-left: auto; flex-wrap: wrap; }
.topnav a { color: var(--ink-soft); font-size: .9rem; }
.topnav a:hover { color: var(--ink); }
.theme-toggle {
  background: var(--bg-sunk); border: 1px solid var(--line);
  color: var(--ink-soft); border-radius: 8px; padding: 5px 10px;
  font-size: .82rem; cursor: pointer; font-family: inherit;
}
.theme-toggle:hover { color: var(--ink); border-color: var(--accent); }

/* ---------- hero ---------- */
.hero { padding: 52px 0 30px; border-bottom: 1px solid var(--line-soft); }
.hero h1 {
  font-size: clamp(1.7rem, 3.6vw, 2.5rem);
  line-height: 1.12; letter-spacing: -.02em; margin: 0 0 14px;
  font-weight: 700;
}
.hero .lede { font-size: 1.12rem; color: var(--ink-soft); max-width: 64ch; margin: 0 0 22px; }
.hero .meta {
  display: flex; flex-wrap: wrap; gap: 10px 18px;
  font-size: .85rem; color: var(--ink-faint);
}
.hero .meta b { color: var(--ink-soft); font-weight: 600; }
.pill {
  display: inline-flex; align-items: center; gap: 6px;
  background: var(--bg-sunk); border: 1px solid var(--line);
  border-radius: 999px; padding: 3px 11px; font-size: .8rem; color: var(--ink-soft);
}

/* ---------- ladder overview ---------- */
.ladder-key { padding: 30px 0 8px; }
.ladder-key h2 { font-size: 1.25rem; margin: 0 0 6px; letter-spacing: -.01em; }
.ladder-key p { color: var(--ink-soft); max-width: 70ch; margin: 0 0 20px; }

.ladder-strip {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin: 0 0 8px;
}
.ladder-strip .step {
  background: var(--bg-elev); border: 1px solid var(--line);
  border-top: 4px solid var(--c); border-radius: var(--radius);
  padding: 14px 14px 16px; box-shadow: var(--shadow);
}
.ladder-strip .step .num { font-size: .72rem; color: var(--ink-faint); font-weight: 600; letter-spacing: .06em; text-transform: uppercase; }
.ladder-strip .step .name { font-size: 1.05rem; font-weight: 700; margin: 2px 0 4px; }
.ladder-strip .step .q { font-size: .86rem; color: var(--ink-soft); margin: 0 0 8px; }
.ladder-strip .step .state {
  font-size: .76rem; font-weight: 600; border-radius: 6px;
  padding: 2px 8px; display: inline-block;
  background: var(--bg-sunk); color: var(--ink-soft);
}
.state.weak { color: var(--flag); }
.state.mixed { color: var(--rung-authority); }
.state.strong { color: var(--up); }

/* ---------- rung sections ---------- */
.rung { padding: 38px 0 12px; scroll-margin-top: 70px; }
.rung-head { display: flex; align-items: baseline; gap: 14px; flex-wrap: wrap; margin: 0 0 4px; }
.rung-head .badge {
  font-size: .72rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase;
  color: #fff; background: var(--c); border-radius: 6px; padding: 3px 9px;
}
.rung-head h2 { font-size: 1.5rem; margin: 0; letter-spacing: -.01em; }
.rung-head .rq { color: var(--ink-soft); font-size: .98rem; }
.rung-sub { color: var(--ink-soft); max-width: 74ch; margin: 6px 0 22px; font-size: .96rem; }

/* surface card grid */
.surfaces {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(248px, 1fr));
  gap: 14px; margin: 0 0 26px;
}
.surface {
  display: block; background: var(--bg-elev); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 16px; box-shadow: var(--shadow);
  transition: border-color .14s ease, transform .14s ease;
  position: relative; color: inherit;
}
.surface:hover { border-color: var(--c); transform: translateY(-2px); text-decoration: none; }
.surface:hover .surface-name { color: var(--c); }
.surface .surface-name {
  font-weight: 700; font-size: 1.02rem; margin: 0 0 4px;
  display: flex; align-items: center; justify-content: space-between; gap: 8px;
}
.surface .arrow { color: var(--ink-faint); font-weight: 400; transition: transform .14s; }
.surface:hover .arrow { transform: translate(3px,-3px); color: var(--c); }
.surface .surface-role { font-size: .85rem; color: var(--ink-soft); margin: 0 0 8px; }
.surface .surface-url { font-size: .76rem; color: var(--ink-faint); font-family: ui-monospace, SFMono-Regular, Menlo, monospace; word-break: break-all; }
.surface .tag {
  position: absolute; top: 14px; right: 14px;
}

/* ---------- figure blocks ---------- */
.figure {
  background: var(--bg-elev); border: 1px solid var(--line);
  border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow);
  margin: 0 0 22px;
}
.figure .fig-head { padding: 14px 18px 0; }
.figure .fig-num { font-size: .72rem; font-weight: 700; letter-spacing: .07em; text-transform: uppercase; color: var(--accent); }
.figure .fig-title { font-size: 1.05rem; font-weight: 700; margin: 3px 0 6px; }
.figure .fig-finding { color: var(--ink-soft); font-size: .92rem; margin: 0 0 12px; }
/* white plate so matplotlib SVGs (white bg, dark ink) stay legible in dark mode */
.figure .plate {
  background: #ffffff; padding: 10px; border-top: 1px solid var(--line-soft);
}
.figure .plate img { display: block; width: 100%; height: auto; }
.figure figcaption {
  padding: 10px 18px 14px; font-size: .8rem; color: var(--ink-faint);
  display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap;
}
.figure figcaption .tier { font-family: ui-monospace, monospace; }

/* ---------- claim ladder (HEADLINE -> WARRANT -> BEDROCK) ---------- */
.claim-ladder {
  border: 1px solid var(--accent);
  border-radius: var(--radius); overflow: hidden;
  margin: 8px 0 26px; box-shadow: var(--shadow);
  background: var(--bg-elev);
}
.claim-ladder .cl-flag {
  background: var(--accent); color: #fff; font-size: .72rem; font-weight: 700;
  letter-spacing: .07em; text-transform: uppercase; padding: 6px 18px;
}
.cl-rung { padding: 16px 18px; border-bottom: 1px solid var(--line-soft); }
.cl-rung:last-child { border-bottom: 0; }
.cl-rung .cl-label {
  font-size: .7rem; font-weight: 700; letter-spacing: .1em; text-transform: uppercase;
  color: var(--ink-faint); margin: 0 0 6px;
  display: flex; align-items: center; gap: 8px;
}
.cl-rung .cl-label .step-dot {
  width: 18px; height: 18px; border-radius: 50%; display: inline-grid; place-items: center;
  font-size: .68rem; color: #fff; background: var(--accent);
}
.cl-headline .cl-body { font-size: 1.18rem; font-weight: 600; line-height: 1.3; }
.cl-warrant .cl-body { font-size: .95rem; color: var(--ink-soft); }
.cl-warrant .stat {
  font-family: ui-monospace, monospace; background: var(--bg-sunk);
  border: 1px solid var(--line); border-radius: 6px; padding: 1px 7px;
  color: var(--ink); white-space: nowrap;
}
.cl-bedrock { background: var(--bg-sunk); }
.cl-bedrock .cl-body { font-size: .92rem; color: var(--ink-soft); }
.bedrock-link {
  display: inline-flex; align-items: center; gap: 7px; margin-top: 8px;
  background: var(--accent); color: #fff; border-radius: 8px;
  padding: 8px 14px; font-size: .88rem; font-weight: 600;
}
.bedrock-link:hover { background: var(--accent-ink); text-decoration: none; color: #fff; }
.proof-ceiling {
  margin-top: 10px; font-size: .78rem; color: var(--ink-faint);
  border-left: 3px solid var(--line); padding-left: 10px;
}
.proof-ceiling b { color: var(--ink-soft); }

/* ---------- grammar explainer ---------- */
.grammar { padding: 30px 0 4px; }
.grammar h2 { font-size: 1.25rem; margin: 0 0 6px; }
.grammar p { color: var(--ink-soft); max-width: 72ch; }
.grammar-flow { display: flex; align-items: stretch; gap: 0; flex-wrap: wrap; margin: 14px 0 4px; }
.grammar-flow .gf {
  flex: 1 1 200px; background: var(--bg-elev); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 14px 16px; box-shadow: var(--shadow);
}
.grammar-flow .gf .gf-k { font-size: .72rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--accent); }
.grammar-flow .gf h3 { margin: 4px 0 4px; font-size: 1rem; }
.grammar-flow .gf p { font-size: .85rem; margin: 0; }
.grammar-flow .gf-arrow { display: grid; place-items: center; color: var(--ink-faint); font-size: 1.4rem; padding: 0 6px; }

/* ---------- overlays note ---------- */
.overlays { padding: 30px 0 8px; }
.overlays h2 { font-size: 1.25rem; margin: 0 0 12px; }
.overlay-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 14px; }
.overlay {
  background: var(--bg-elev); border: 1px solid var(--line); border-left: 4px solid var(--accent);
  border-radius: var(--radius); padding: 14px 16px; box-shadow: var(--shadow);
}
.overlay h3 { margin: 0 0 6px; font-size: 1rem; }
.overlay p { margin: 0; font-size: .86rem; color: var(--ink-soft); }
.overlay.refuted { border-left-color: var(--ink-faint); }
.overlay.refuted h3 .x { color: var(--flag); }

/* ---------- footer ---------- */
.site-foot {
  border-top: 1px solid var(--line); margin-top: 40px; padding: 28px 0 50px;
  color: var(--ink-faint); font-size: .85rem;
}
.site-foot h3 { color: var(--ink-soft); font-size: .95rem; margin: 0 0 8px; }
.site-foot p { max-width: 78ch; margin: 0 0 10px; }
.site-foot .edition {
  font-family: ui-monospace, monospace; background: var(--bg-sunk);
  border: 1px solid var(--line); border-radius: 6px; padding: 2px 8px; color: var(--ink-soft);
}

/* ---------- responsive ---------- */
@media (max-width: 860px) {
  .ladder-strip { grid-template-columns: repeat(2, 1fr); }
  .grammar-flow .gf-arrow { transform: rotate(90deg); width: 100%; padding: 4px 0; }
}
@media (max-width: 520px) {
  .ladder-strip { grid-template-columns: 1fr; }
  .hero { padding: 36px 0 24px; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; scroll-behavior: auto !important; }
}