/* PolyLabs Research. One reading column of about 66ch; interactive figures are wider panels set
   between passages, and on wide screens a figure puts its canvas beside its controls. */
:root {
  --paper: #f2f4f1;
  --panel: #ffffff;
  --ink: #17201c;
  --muted: #59645f;
  --line: #d2d9d4;
  --cell: #155f78;
  --cell-soft: #b9d3dc;
  --gold: #a1660d;
  --gold-soft: #f0dcb4;
  --ok: #2b7647;
  --bad: #a3392a;
  --serif: "STIX Two Text", "STIX Two", "Cambria", "Times New Roman", serif;
  --mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --step--1: 0.84rem;
  --step-0: 1.06rem;
  --step-1: 1.3rem;
  --step-2: 1.7rem;
  --step-3: 2.6rem;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #0e1416;
    --panel: #151e21;
    --ink: #e1e8e4;
    --muted: #97a59f;
    --line: #2a3638;
    --cell: #5cc0dd;
    --cell-soft: #1d4855;
    --gold: #e6aa45;
    --gold-soft: #4f3b15;
    --ok: #6cc28b;
    --bad: #e57d6a;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #0e1416;
  --panel: #151e21;
  --ink: #e1e8e4;
  --muted: #97a59f;
  --line: #2a3638;
  --cell: #5cc0dd;
  --cell-soft: #1d4855;
  --gold: #e6aa45;
  --gold-soft: #4f3b15;
  --ok: #6cc28b;
  --bad: #e57d6a;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: var(--step-0);
  line-height: 1.58;
}
.gutter {
  padding-left: max(16px, env(safe-area-inset-left, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px));
}
.wrap { max-width: 980px; margin: 0 auto; padding-block: 40px 72px; display: grid; gap: 40px; }
.prose { max-width: 66ch; display: grid; gap: 14px; }
.prose p, .prose ul, .prose ol { margin: 0; }
.prose ul, .prose ol { padding-left: 1.2em; display: grid; gap: 6px; }
h1, h2, h3 { font-weight: 600; text-wrap: balance; margin: 0; line-height: 1.2; }
h1 { font-size: var(--step-3); letter-spacing: -0.01em; }
h2 { font-size: var(--step-2); }
h3 { font-size: var(--step-1); }
.eyebrow {
  font-family: var(--mono); font-size: var(--step--1); letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--muted);
}
.lede { font-size: var(--step-1); line-height: 1.45; max-width: 60ch; margin: 0; }
code, .mono { font-family: var(--mono); font-size: 0.88em; }
em.var { font-style: italic; }
a { color: var(--cell); text-underline-offset: 0.15em; }
a:focus-visible, button:focus-visible, select:focus-visible, input:focus-visible, textarea:focus-visible, [tabindex]:focus-visible {
  outline: 2px solid var(--gold); outline-offset: 2px;
}
sub, sup { line-height: 0; }

/* site header and footer */
.site-head { border-bottom: 1px solid var(--line); background: var(--paper); }
.site-head .bar {
  max-width: 980px; margin: 0 auto; padding-block: 14px; display: flex; flex-wrap: wrap;
  align-items: center; justify-content: space-between; gap: 10px 24px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; }
.brand-mark { width: 26px; height: 26px; display: block; }
.brand-name { font-family: var(--mono); font-size: 0.95rem; font-weight: 500; letter-spacing: 0.02em; }
.nav { display: flex; flex-wrap: wrap; gap: 4px 18px; font-family: var(--mono); font-size: var(--step--1); }
.nav a { color: var(--muted); text-decoration: none; padding-block: 4px; border-bottom: 2px solid transparent; }
.nav a:hover { color: var(--ink); }
.nav a[aria-current="page"] { color: var(--ink); border-bottom-color: var(--cell); }
.site-foot { border-top: 1px solid var(--line); color: var(--muted); font-size: var(--step--1); }
.site-foot .bar { max-width: 980px; margin: 0 auto; padding-block: 28px 40px; display: grid; gap: 10px; }
.site-foot p { margin: 0; max-width: 72ch; }
.site-foot .links { display: flex; flex-wrap: wrap; gap: 6px 18px; font-family: var(--mono); }

/* home */
.hero { display: grid; gap: 28px; grid-template-columns: minmax(0, 1fr); align-items: center; }
@media (min-width: 820px) { .hero { grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr); } }
.hero-text { display: grid; gap: 18px; }
.hero-fig { display: grid; gap: 8px; justify-items: stretch; }
.hero-fig .canvas-box { max-width: 380px; justify-self: center; }
.cta { display: flex; flex-wrap: wrap; gap: 10px; }
.cta a {
  font-family: var(--mono); font-size: 0.88rem; text-decoration: none; padding: 8px 14px;
  border-radius: 4px; border: 1px solid var(--line); color: var(--ink); background: var(--panel);
}
.cta a.primary { background: var(--cell); color: var(--panel); border-color: var(--cell); }
.cards { display: grid; gap: 14px; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
.card {
  background: var(--panel); border: 1px solid var(--line); border-radius: 6px; padding: 18px;
  display: grid; gap: 10px; align-content: start; color: var(--ink); text-decoration: none;
}
a.card:hover { border-color: var(--cell); }
.card h3 { font-size: 1.12rem; }
.card p { margin: 0; font-size: 0.97rem; }
.card .status { justify-self: start; }

/* figures */
.figure {
  background: var(--panel); border: 1px solid var(--line); border-radius: 6px;
  padding: 20px; display: grid; gap: 18px; min-width: 0;
}
.figure-head { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 8px 20px; }
.figure-head h2, .figure-head h3 { font-size: var(--step-1); }
.figure-body { display: grid; gap: 20px; grid-template-columns: minmax(0, 1fr); }
@media (min-width: 780px) {
  .figure-body.split { grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr); align-items: start; }
}
.canvas-box { position: relative; width: 100%; max-width: 560px; aspect-ratio: 1 / 1; }
.canvas-box canvas { width: 100%; height: 100%; display: block; border-radius: 3px; }
.controls { display: grid; gap: 14px; min-width: 0; }
.row { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
label.field, .field { display: grid; gap: 4px; font-family: var(--mono); font-size: var(--step--1); color: var(--muted); min-width: 0; }
select, input[type="number"], textarea {
  font-family: var(--mono); font-size: 0.9rem; color: var(--ink); background: var(--paper);
  border: 1px solid var(--line); border-radius: 4px; padding: 6px 8px; min-width: 0; max-width: 100%;
}
input[type="range"] { width: 100%; accent-color: var(--cell); }
button {
  font-family: var(--mono); font-size: 0.86rem; color: var(--ink); background: var(--paper);
  border: 1px solid var(--line); border-radius: 4px; padding: 7px 12px; cursor: pointer;
}
button:hover { border-color: var(--cell); }
button.primary { background: var(--cell); color: var(--panel); border-color: var(--cell); }
.seg { display: inline-flex; flex-wrap: wrap; border: 1px solid var(--line); border-radius: 4px; overflow: hidden; }
.seg button { border: 0; border-radius: 0; }
.seg button[aria-pressed="true"] { background: var(--cell); color: var(--panel); }

.readout { display: grid; gap: 8px; font-family: var(--mono); font-size: 0.86rem; }
.readout .kv { display: grid; grid-template-columns: 9.5em minmax(0, 1fr); gap: 10px; align-items: baseline; }
.readout .k { color: var(--muted); }
.readout .v { font-variant-numeric: tabular-nums; overflow-wrap: anywhere; }
.big { font-family: var(--mono); font-size: var(--step-2); font-variant-numeric: tabular-nums; line-height: 1.1; }
.formula { font-size: var(--step-1); margin: 0; }
.badge {
  display: inline-block; font-family: var(--mono); font-size: 0.78rem; letter-spacing: 0.03em;
  padding: 2px 8px; border-radius: 999px; border: 1px solid currentColor; white-space: nowrap;
}
.readout .badge, .status-line .badge { white-space: normal; }
.badge.ok { color: var(--ok); }
.badge.bad { color: var(--bad); }
.badge.gold { color: var(--gold); }
.badge.muted { color: var(--muted); }
.note { font-size: var(--step--1); color: var(--muted); margin: 0; }

/* charts */
.chart-box { width: 100%; overflow-x: auto; }
.chart-box svg { width: 100%; min-width: 520px; height: auto; display: block; }
.tip {
  font-family: var(--mono); font-size: 0.82rem; min-height: 3.2em; color: var(--ink);
  font-variant-numeric: tabular-nums; overflow-wrap: anywhere;
}
.legend { display: flex; flex-wrap: wrap; gap: 6px 18px; font-family: var(--mono); font-size: var(--step--1); color: var(--muted); }
.legend span { display: inline-flex; align-items: center; gap: 6px; }
.swatch { width: 11px; height: 11px; border-radius: 50%; display: inline-block; flex: none; }
.swatch.sq { border-radius: 2px; }

/* stencils */
.ident { display: grid; gap: 14px; }
.eq { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 14px; }
.stencil { display: grid; gap: 4px; justify-items: center; }
.stencil svg { display: block; max-width: 100%; height: auto; }
.stencil .cap { font-family: var(--mono); font-size: 0.74rem; color: var(--muted); text-align: center; max-width: 18ch; }
.op { font-family: var(--mono); font-size: 1.3rem; color: var(--muted); }

/* tables */
.table-box { overflow-x: auto; }
table { border-collapse: collapse; width: 100%; min-width: 560px; font-size: 0.95rem; }
th, td { text-align: left; vertical-align: top; padding: 9px 10px; border-bottom: 1px solid var(--line); }
th { font-family: var(--mono); font-size: var(--step--1); font-weight: 500; color: var(--muted); letter-spacing: 0.04em; }
td code { white-space: nowrap; }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; }

/* the loop */
.loop { display: grid; gap: 18px; grid-template-columns: minmax(0, 1fr); }
@media (min-width: 820px) { .loop { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); align-items: start; } }
.loop svg { width: 100%; max-width: 460px; height: auto; display: block; justify-self: center; }
.loop .node { cursor: pointer; }
.loop .node:focus { outline: none; }
.loop .node:focus-visible rect { stroke: var(--gold); stroke-width: 2.5; }
.stage { display: grid; gap: 10px; align-content: start; }
.stage p, .stage ul { margin: 0; }
.stage ul { padding-left: 1.2em; display: grid; gap: 4px; }

/* ledger */
.chain { display: grid; gap: 6px; max-height: 520px; overflow-y: auto; padding-right: 4px; }
.entry {
  display: grid; grid-template-columns: 2.2em minmax(0, 1fr) auto; gap: 4px 10px; align-items: baseline;
  font-family: var(--mono); font-size: 0.8rem; padding: 7px 9px; border: 1px solid var(--line);
  border-radius: 4px; background: var(--paper); cursor: pointer; text-align: left; color: var(--ink);
  width: 100%;
}
.entry[aria-pressed="true"] { border-color: var(--cell); }
.entry.broken { border-color: var(--bad); }
.entry .seq { color: var(--muted); }
.entry .kind { overflow-wrap: anywhere; }
.entry .h { grid-column: 2 / 4; color: var(--muted); overflow-wrap: anywhere; font-size: 0.74rem; }
textarea.body { width: 100%; min-height: 220px; font-size: 0.78rem; line-height: 1.45; resize: vertical; }

/* asides */
.open {
  border-left: 3px solid var(--gold); padding: 4px 0 4px 18px; display: grid; gap: 14px; max-width: 70ch;
}
.open p { margin: 0; }
.sixlist { margin: 0; padding-left: 1.2em; display: grid; gap: 2px; font-family: var(--mono); font-size: 0.86rem; }
.pullquote { border-left: 3px solid var(--cell); padding: 2px 0 2px 16px; margin: 0; max-width: 62ch; }
.steps { counter-reset: step; display: grid; gap: 12px; padding: 0; margin: 0; list-style: none; max-width: 66ch; }
.steps li { counter-increment: step; display: grid; grid-template-columns: 2em minmax(0, 1fr); gap: 10px; }
.steps li::before { content: counter(step); font-family: var(--mono); color: var(--cell); font-weight: 500; }
@media (prefers-reduced-motion: reduce) { * { scroll-behavior: auto !important; } }