/* Planar website. Editorial serif headings, quiet neutrals, and the five
   item colours as the only accents. */
:root {
  color-scheme: light;
  --bg: #fbfbf9; --bg-2: #f2f2ee; --panel: #ffffff;
  --ink: #141517; --ink-2: #3c3e43; --muted: #6c6f76; --faint: #9a9da4;
  --line: #e6e6e1; --line-2: #d4d4ce;
  --dec: #2563eb; --req: #0d9488; --task: #b7791f; --risk: #dc2626; --q: #ea580c; --step: #16a34a;
  --wire: #c9cad0;
  --shadow: 0 1px 2px rgb(20 21 23 / .04), 0 18px 48px -18px rgb(20 21 23 / .18);
  --serif: 'Instrument Serif', 'Iowan Old Style', Georgia, serif;
  --sans: 'Inter', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --mono: 'JetBrains Mono', ui-monospace, 'Cascadia Mono', Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme='light']) {
    color-scheme: dark;
    --bg: #0e0f11; --bg-2: #15171a; --panel: #17191c;
    --ink: #ecedef; --ink-2: #c4c6cb; --muted: #8d9098; --faint: #61646b;
    --line: #25282d; --line-2: #33363c;
    --dec: #60a5fa; --req: #2dd4bf; --task: #f0b54a; --risk: #f87171; --q: #fb923c; --step: #4ade80;
    --wire: #3a3d44;
    --shadow: 0 1px 2px rgb(0 0 0 / .4), 0 24px 60px -24px rgb(0 0 0 / .7);
  }
}
:root[data-theme='dark'] {
  color-scheme: dark;
  --bg: #0e0f11; --bg-2: #15171a; --panel: #17191c;
  --ink: #ecedef; --ink-2: #c4c6cb; --muted: #8d9098; --faint: #61646b;
  --line: #25282d; --line-2: #33363c;
  --dec: #60a5fa; --req: #2dd4bf; --task: #f0b54a; --risk: #f87171; --q: #fb923c; --step: #4ade80;
  --wire: #3a3d44;
  --shadow: 0 1px 2px rgb(0 0 0 / .4), 0 24px 60px -24px rgb(0 0 0 / .7);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 76px; }
html, body { margin: 0; overflow-x: clip; }
body { font: 16px/1.6 var(--sans); background: var(--bg); color: var(--ink); -webkit-font-smoothing: antialiased; }
a { color: inherit; }
code, pre { font-family: var(--mono); }
:focus-visible { outline: 2px solid var(--dec); outline-offset: 3px; border-radius: 4px; }
.shell { max-width: 1140px; margin: 0 auto; padding-inline: 32px; }
.quiet { color: var(--muted); }

/* ---------- header ---------- */
.top { position: sticky; top: 0; z-index: 30; background: color-mix(in srgb, var(--bg) 82%, transparent); backdrop-filter: saturate(1.4) blur(12px); }
.top-inner { display: flex; align-items: center; gap: 28px; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; font-weight: 600; font-size: 16px; letter-spacing: -.01em; }
.brand img { border-radius: 7px; }
.links { display: flex; gap: 26px; margin-left: auto; font-size: 14px; }
.links a { text-decoration: none; color: var(--muted); transition: color .15s; }
.links a:hover { color: var(--ink); }
.theme { width: 36px; height: 36px; display: grid; place-items: center; border: 0; border-radius: 50%; background: var(--bg-2); color: var(--ink); cursor: pointer; }
.theme svg { width: 17px; height: 17px; }

/* ---------- hero ---------- */
.hero { padding-block: 56px 88px; text-align: center; }
.pill { display: inline-flex; align-items: center; gap: 8px; margin: 0 0 26px; padding: 6px 14px; border: 1px solid var(--line); border-radius: 999px; font-size: 13px; color: var(--ink-2); background: var(--panel); }
.pill .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--step); box-shadow: 0 0 0 3px color-mix(in srgb, var(--step) 22%, transparent); }
h1 { margin: 0; font: 400 clamp(46px, 7.4vw, 92px)/.98 var(--serif); letter-spacing: -.02em; }
h1 em { color: var(--muted); }
.sub { max-width: 640px; margin: 26px auto 0; font-size: 18px; color: var(--ink-2); }
.kw { font-weight: 600; }
.kw-dec { color: var(--dec); } .kw-req { color: var(--req); } .kw-task { color: var(--task); } .kw-risk { color: var(--risk); } .kw-q { color: var(--q); }
.actions { display: flex; justify-content: center; flex-wrap: wrap; gap: 12px; margin-top: 34px; }
.button { display: inline-flex; align-items: center; height: 46px; padding: 0 22px; border-radius: 999px; border: 1px solid var(--line-2); background: var(--panel); text-decoration: none; font-weight: 500; font-size: 15px; transition: transform .15s, border-color .15s; }
.button:hover { transform: translateY(-1px); border-color: var(--ink); }
.button.solid { background: var(--ink); color: var(--bg); border-color: var(--ink); }

/* trace diagram */
.trace { position: relative; display: grid; grid-template-columns: 1.15fr 1fr .8fr; gap: 56px; margin: 64px 0 0; padding: 28px 30px 20px; text-align: left; border: 1px solid var(--line); border-radius: 22px; background: var(--panel); box-shadow: var(--shadow); }
.wires { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; overflow: visible; }
.wires path { fill: none; stroke: var(--wire); stroke-width: 1.4; transition: stroke .2s, stroke-width .2s, opacity .2s; }
.trace.focus .wires path { opacity: .25; }
.trace.focus .wires path.lit { opacity: 1; stroke: var(--ink-2); stroke-width: 1.8; }
.col { position: relative; z-index: 1; display: flex; flex-direction: column; gap: 10px; }
.col-plan { justify-content: center; gap: 56px; }
.col-head { margin: 0 0 4px; font: 500 11.5px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase; color: var(--faint); }
.line, .item, .step { margin: 0; font-size: 13px; line-height: 1.45; border-radius: 10px; transition: opacity .2s, background .2s, border-color .2s; }
.line { display: grid; grid-template-columns: 42px minmax(0, 1fr); padding: 7px 10px; color: var(--muted); background: var(--bg-2); }
.line b { font: 500 11.5px/1.7 var(--mono); color: var(--faint); }
.item { padding: 8px 12px 9px; border: 1px solid var(--line); border-left: 3px solid var(--c); background: var(--panel); color: var(--ink); cursor: default; }
.item i { display: block; font: 600 10.5px/1.6 var(--mono); font-style: normal; letter-spacing: .05em; text-transform: uppercase; color: var(--c); }
.k-dec { --c: var(--dec); } .k-req { --c: var(--req); } .k-task { --c: var(--task); } .k-risk { --c: var(--risk); } .k-q { --c: var(--q); } .k-step { --c: var(--step); }
.step { display: grid; grid-template-columns: 28px minmax(0, 1fr); align-items: start; padding: 12px 14px; border: 1px solid color-mix(in srgb, var(--step) 40%, var(--line)); background: color-mix(in srgb, var(--step) 7%, var(--panel)); font-weight: 500; }
.step .n { display: grid; place-items: center; width: 20px; height: 20px; border-radius: 50%; background: var(--step); color: var(--panel); font: 600 11px/1 var(--mono); }
.step small { grid-column: 2; margin-top: 4px; font: 400 12px/1.4 var(--mono); color: var(--muted); }
.trace.focus .line, .trace.focus .item, .trace.focus .step { opacity: .35; }
.trace.focus .lit { opacity: 1; }
.trace.focus .line.lit { color: var(--ink); background: color-mix(in srgb, var(--c, var(--ink)) 10%, var(--bg-2)); }
.trace figcaption { grid-column: 1 / -1; margin-top: 4px; font-size: 12.5px; color: var(--faint); text-align: center; }

/* ---------- shared section intro ---------- */
section { padding-block: 96px; }
.intro h2 { margin: 0; font: 400 clamp(36px, 4.6vw, 54px)/1.04 var(--serif); letter-spacing: -.015em; }
.intro p { margin: 16px 0 0; max-width: 560px; color: var(--ink-2); font-size: 17px; }
.intro.wide p { max-width: 720px; }
.intro a { text-decoration-color: var(--line-2); }

/* ---------- demo band ---------- */
.band { background: var(--bg-2); border-block: 1px solid var(--line); }
.band .intro { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 48px; align-items: end; }
.band .intro p { margin: 0; }
.meetings { display: flex; flex-wrap: wrap; gap: 8px; margin: 40px 0 16px; }
.meetings button { padding: 8px 15px; border: 1px solid var(--line-2); border-radius: 999px; background: var(--panel); color: var(--ink-2); font: 500 13.5px/1.2 var(--sans); cursor: pointer; transition: background .15s, color .15s, border-color .15s; }
.meetings button:hover { border-color: var(--ink); color: var(--ink); }
.meetings button[aria-selected='true'] { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.stage { border-radius: 22px; overflow: hidden; border: 1px solid var(--line); background: var(--bg); box-shadow: var(--shadow); }
.stage iframe { display: block; width: 100%; height: min(860px, 84vh); border: 0; }
.aside { margin: 14px 0 0; font-size: 13.5px; color: var(--muted); }
.aside a { color: var(--ink-2); }

/* ---------- how ---------- */
.split { display: grid; grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr); gap: 72px; align-items: start; }
.sticky { position: sticky; top: 100px; }
.flow { list-style: none; margin: 0; padding: 0; }
.flow li { position: relative; padding: 0 0 40px 40px; }
.flow li::before { content: ''; position: absolute; left: 7px; top: 22px; bottom: 0; width: 1px; background: var(--line-2); }
.flow li:last-child { padding-bottom: 0; }
.flow li:last-child::before { display: none; }
.mark { position: absolute; left: 0; top: 6px; width: 15px; height: 15px; border-radius: 50%; border: 3px solid var(--c); background: var(--bg); }
.flow h3 { margin: 0; font-size: 19px; font-weight: 600; letter-spacing: -.01em; }
.flow p { margin: 8px 0 12px; color: var(--ink-2); }
.flow code { display: inline-block; padding: 4px 10px; border-radius: 6px; background: var(--bg-2); color: var(--muted); font-size: 12px; }

/* ---------- accuracy ---------- */
.stats { display: grid; grid-template-columns: auto auto minmax(0, 1fr); gap: 56px; align-items: end; margin: 48px 0 32px; }
.stats div { display: flex; flex-direction: column; }
.big { font: 400 clamp(64px, 8vw, 104px)/.9 var(--serif); letter-spacing: -.03em; }
.stats div:nth-child(1) .big { color: var(--step); }
.stats div:nth-child(2) .big { color: var(--dec); }
.label { margin-top: 10px; max-width: 180px; font-size: 14px; color: var(--muted); }
.reading { margin: 0; color: var(--ink-2); font-size: 15px; }
.table { overflow-x: auto; border: 1px solid var(--line); border-radius: 16px; background: var(--panel); }
table { width: 100%; border-collapse: collapse; font-size: 14.5px; }
th, td { padding: 14px 18px; text-align: left; border-top: 1px solid var(--line); white-space: nowrap; }
thead th { border-top: 0; font: 500 11.5px/1.4 var(--mono); letter-spacing: .06em; text-transform: uppercase; color: var(--faint); }
td:first-child { white-space: normal; min-width: 240px; }
td.num { font-variant-numeric: tabular-nums; color: var(--ink-2); }
tr.total td { background: var(--bg-2); font-weight: 600; }
.bar { display: inline-flex; align-items: center; gap: 10px; font-variant-numeric: tabular-nums; }
.bar i { position: relative; width: 84px; height: 6px; border-radius: 3px; background: var(--bg-2); overflow: hidden; }
.bar i::after { content: ''; position: absolute; inset: 0 auto 0 0; width: var(--v); background: var(--c); border-radius: 3px; }

/* ---------- run ---------- */
.notes { margin: 24px 0 0; padding: 0; list-style: none; display: grid; gap: 10px; color: var(--ink-2); font-size: 15px; }
.notes li { padding-left: 18px; position: relative; }
.notes li::before { content: ''; position: absolute; left: 0; top: .7em; width: 6px; height: 6px; border-radius: 50%; background: var(--line-2); }
.notes code, .intro code { font-size: 12.5px; padding: 2px 6px; border-radius: 5px; background: var(--bg-2); }
.code { position: relative; border-radius: 18px; background: #111214; color: #d6d8dd; box-shadow: var(--shadow); }
:root[data-theme='dark'] .code { border: 1px solid var(--line); }
.code pre { margin: 0; padding: 26px 28px; font-size: 13.5px; line-height: 1.75; overflow-x: auto; }
.code .c { color: #6d7179; }
.copy { position: absolute; top: 14px; right: 14px; padding: 6px 12px; border: 1px solid #2c2f35; border-radius: 8px; background: #1a1c20; color: #c9ccd2; font: 500 12px/1 var(--sans); cursor: pointer; }
.copy:hover { color: #fff; border-color: #4a4e56; }

/* ---------- footer ---------- */
.foot { display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; padding-block: 36px 44px; border-top: 1px solid var(--line); font-size: 14px; color: var(--muted); }
.foot span { display: inline-flex; align-items: center; gap: 8px; }
.foot img { border-radius: 4px; }
.foot a { color: var(--ink-2); }

/* ---------- responsive ---------- */
@media (max-width: 980px) {
  .trace { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 28px; }
  .col-plan { grid-column: 1 / -1; flex-direction: row; gap: 12px; }
  .col-plan .col-head { display: none; }
  .col-plan .step { flex: 1; }
  .wires { display: none; }
  .split, .band .intro { grid-template-columns: minmax(0, 1fr); gap: 28px; }
  .sticky { position: static; }
  .stats { grid-template-columns: auto auto; }
  .reading { grid-column: 1 / -1; }
}
@media (max-width: 640px) {
  .shell { padding-inline: 16px; }
  .links .wide { display: none; }
  .links { gap: 18px; }
  .hero { padding-block: 36px 64px; }
  .sub { font-size: 16.5px; }
  .trace { grid-template-columns: minmax(0, 1fr); padding: 20px 16px 16px; }
  .trace .col:first-of-type { display: none; }
  .item[data-from]::after { content: '← ' attr(data-from); display: block; margin-top: 4px; font: 11.5px/1.4 var(--mono); color: var(--faint); }
  .col-plan { flex-direction: column; }
  section { padding-block: 64px; }
  .stats { gap: 28px; }
  .stage iframe { height: 78vh; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}