:root {
  --paper: #f4f1e8;
  --surface: #fbfaf5;
  --ink: #16150f;
  --muted: #5d5a4f;
  --faint: #8a8676;
  --rule: #d9d4c4;
  --accent: #c4432b;
  --accent-soft: #f3ddd4;
  --accent-ink: #a3321d;
  --grey-token: #cfcabb;
  --serif: "Source Serif 4", Georgia, "Times New Roman", serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #15140f;
    --surface: #1d1c16;
    --ink: #ece8dc;
    --muted: #b1ac9c;
    --faint: #8a8676;
    --rule: #34322a;
    --accent: #e8664c;
    --accent-soft: #3a211a;
    --accent-ink: #f08a73;
    --grey-token: #4a473d;
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 64px; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 16px/1.65 var(--sans); -webkit-font-smoothing: antialiased; }
a { color: var(--accent-ink); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3 { font-family: var(--serif); line-height: 1.2; margin: 0; }
h2 { font-size: clamp(1.6rem, 3.2vw, 2.2rem); font-weight: 600; letter-spacing: -.01em; }
h3 { font-size: 1.15rem; font-weight: 600; }
p { margin: 0 0 1rem; }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 16px; }
.mono { font-family: var(--mono); }
.label { font-family: var(--mono); font-size: .72rem; letter-spacing: .08em; text-transform: uppercase; color: var(--faint); }
.label b { color: var(--accent); font-weight: 500; }

/* Nav */
.nav { position: sticky; top: 0; z-index: 10; background: color-mix(in srgb, var(--paper) 92%, transparent); backdrop-filter: blur(8px); border-bottom: 1px solid var(--rule); }
.nav .wrap { display: flex; align-items: center; gap: 1.25rem; padding-top: .7rem; padding-bottom: .7rem; flex-wrap: wrap; }
.nav .brand { font-family: var(--serif); font-weight: 700; font-size: 1.1rem; color: var(--ink); }
.nav .brand span { color: var(--accent); }
.nav .links { display: flex; gap: 1rem; flex-wrap: wrap; margin-left: auto; font-size: .9rem; }
.nav .links a { color: var(--muted); }
.nav .links a:hover { color: var(--ink); text-decoration: none; }

section { padding: 4rem 0; border-bottom: 1px solid var(--rule); }
.sec-head { margin-bottom: 2rem; max-width: 70ch; }
.sec-head .label { display: block; margin-bottom: .6rem; }
.sec-head p { color: var(--muted); margin-top: .8rem; }

/* Hero */
.hero { padding: 3.5rem 0 4rem; }
.hero .grid { display: grid; grid-template-columns: 1fr 300px; gap: 3rem; align-items: center; }
.tokens { display: flex; flex-wrap: wrap; gap: .5rem; margin-bottom: 1.25rem; }
.tok { border: 1.5px solid var(--ink); padding: .1rem .7rem .2rem; font-family: var(--serif); font-weight: 700; font-size: clamp(2.6rem, 7vw, 4.6rem); line-height: 1; position: relative; }
.tok::after { content: ""; position: absolute; left: -1.5px; right: -1.5px; bottom: -7px; height: 4px; background: var(--accent); }
.tok small { position: absolute; left: 0; bottom: -1.6rem; font: 500 .68rem var(--mono); color: var(--accent); letter-spacing: .04em; }
.hero .sub { font-family: var(--serif); font-size: clamp(1.15rem, 2.4vw, 1.5rem); margin: 2.4rem 0 .4rem; }
.hero .by { color: var(--muted); margin-bottom: 1.4rem; }
.hero blockquote { margin: 0 0 1.6rem; padding-left: 1rem; border-left: 3px solid var(--accent); font-family: var(--serif); font-size: 1.12rem; font-style: italic; max-width: 56ch; }
.hero .cover img { width: 100%; height: auto; display: block; box-shadow: 0 12px 34px rgba(30, 25, 10, .22); }
.btns { display: flex; flex-wrap: wrap; gap: .6rem; }
.btn { display: inline-block; padding: .55rem 1rem; border: 1.5px solid var(--ink); font-size: .92rem; font-weight: 500; color: var(--ink); background: transparent; }
.btn:hover { background: var(--ink); color: var(--paper); text-decoration: none; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.primary:hover { background: var(--accent-ink); border-color: var(--accent-ink); }
.facts { display: flex; gap: 2rem; flex-wrap: wrap; margin-top: 2rem; }
.facts div b { display: block; font: 600 1.5rem var(--serif); }
.facts div span { font-size: .8rem; color: var(--muted); }

/* Chain */
.chain { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; border: 1.5px solid var(--ink); }
.chain > div { padding: 1.4rem 1.3rem; background: var(--surface); position: relative; }
.chain > div + div { border-left: 1.5px solid var(--ink); }
.chain > div + div::before { content: "→"; position: absolute; left: -.8rem; top: 1.25rem; background: var(--paper); color: var(--accent); font-weight: 700; padding: 0 .15rem; }
.chain h3 { margin: .35rem 0 .5rem; font-size: 1.35rem; }
.chain p { color: var(--muted); font-size: .95rem; margin-bottom: .6rem; }
.chain .parts { font-size: .85rem; }
.around { margin-top: 1rem; display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.around > div { border: 1px dashed var(--rule); padding: 1rem 1.2rem; background: var(--surface); font-size: .95rem; }
.around b { font-family: var(--serif); }

/* Results */
.results { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; }
.result { background: var(--surface); border: 1px solid var(--rule); padding: 1.3rem 1.4rem; }
.result .n { font: 500 .8rem var(--mono); color: var(--accent); }
.result h3 { margin: .3rem 0 .5rem; }
.result p { color: var(--muted); font-size: .95rem; margin: 0; }
.result .eq { font-family: var(--mono); font-size: .85rem; color: var(--ink); background: var(--accent-soft); padding: .2rem .5rem; display: inline-block; margin-top: .7rem; }

/* Calculator */
.calc { display: grid; grid-template-columns: 320px 1fr; gap: 2rem; background: var(--surface); border: 1.5px solid var(--ink); padding: 1.5rem; }
.calc fieldset { border: 0; padding: 0; margin: 0; }
.calc legend { font: 500 .72rem var(--mono); text-transform: uppercase; letter-spacing: .08em; color: var(--faint); margin-bottom: .6rem; }
.field { margin-bottom: .95rem; }
.field label { display: flex; justify-content: space-between; font-size: .88rem; margin-bottom: .25rem; }
.field output { font-family: var(--mono); color: var(--accent-ink); }
.field input[type=range] { width: 100%; accent-color: var(--accent); }
.check { display: flex; gap: .5rem; align-items: center; font-size: .9rem; margin-top: .4rem; }
.check input { accent-color: var(--accent); width: 1rem; height: 1rem; }
.note { font-size: .78rem; color: var(--faint); margin-top: .8rem; }
.readout { display: grid; grid-template-columns: repeat(4, 1fr); gap: .75rem; margin-bottom: 1rem; }
.readout div { border-top: 3px solid var(--ink); padding-top: .4rem; }
.readout div.hot { border-top-color: var(--accent); }
.readout b { display: block; font: 600 1.35rem var(--serif); font-variant-numeric: tabular-nums; }
.readout span { font-size: .78rem; color: var(--muted); }
#chart { width: 100%; height: auto; display: block; }
#chart text { font-family: var(--mono); font-size: 11px; fill: var(--muted); }
#chart .axis { stroke: var(--rule); }
#chart .l-nocache { stroke: var(--accent); stroke-width: 2.5; fill: none; }
#chart .l-cache { stroke: var(--ink); stroke-width: 2; fill: none; }
#chart .l-linear { stroke: var(--faint); stroke-width: 1.5; stroke-dasharray: 4 4; fill: none; }
.legend { display: flex; gap: 1.2rem; flex-wrap: wrap; font-size: .8rem; color: var(--muted); margin-top: .4rem; }
.legend i { display: inline-block; width: 18px; height: 0; border-top: 2.5px solid; vertical-align: middle; margin-right: .35rem; }
.formula { font-family: var(--mono); font-size: .88rem; background: var(--accent-soft); padding: .6rem .8rem; margin-top: 1rem; overflow-x: auto; white-space: nowrap; }

.calc > * { min-width: 0; }

/* Audience */
.aud { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
.aud div { border-top: 1.5px solid var(--ink); padding-top: .8rem; }
.aud h3 { font-size: 1.05rem; margin-bottom: .35rem; }
.aud p { color: var(--muted); font-size: .92rem; margin-bottom: .4rem; }
.aud .ch { font: .78rem var(--mono); color: var(--accent-ink); }

/* Contents */
.toc { display: grid; grid-template-columns: repeat(2, 1fr); gap: .5rem 2.5rem; }
.toc details { border-bottom: 1px solid var(--rule); padding: .6rem 0; }
.toc summary { cursor: pointer; font-family: var(--serif); font-weight: 600; font-size: 1.05rem; list-style: none; display: flex; gap: .7rem; align-items: baseline; }
.toc summary::-webkit-details-marker { display: none; }
.toc summary .pn { font: 500 .78rem var(--mono); color: var(--accent); min-width: 2.2rem; }
.toc summary::after { content: "+"; margin-left: auto; color: var(--faint); font-family: var(--mono); }
.toc details[open] summary::after { content: "−"; }
.toc ol { margin: .5rem 0 .2rem 2.9rem; padding: 0; list-style: none; font-size: .93rem; }
.toc ol li { padding: .15rem 0; display: flex; gap: .6rem; }
.toc ol li .c { font-family: var(--mono); font-size: .8rem; color: var(--faint); min-width: 1.6rem; padding-top: .1rem; }
.toc .in-sample { color: var(--accent-ink); font-size: .72rem; font-family: var(--mono); margin-left: .4rem; }

/* Examples */
.examples { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
.ex { background: var(--surface); border: 1px solid var(--rule); padding: 1.2rem 1.3rem; }
.ex .tag { font: 600 .9rem var(--mono); color: #fff; background: var(--ink); padding: .1rem .45rem; }
.ex h3 { margin: .7rem 0 .4rem; }
.ex p { color: var(--muted); font-size: .93rem; margin: 0; }

/* Papers */
.papers { list-style: none; margin: 0; padding: 0; }
.papers li { padding: .8rem 0; border-bottom: 1px dashed var(--rule); }
.papers li:last-child { border-bottom: 0; }
.papers .t { font-family: var(--serif); font-weight: 600; font-size: 1.05rem; }
.papers .m { color: var(--muted); font-size: .9rem; }
.aside { margin-top: 1.5rem; padding: 1rem 1.2rem; border-left: 3px solid var(--accent); background: var(--surface); font-size: .93rem; color: var(--muted); max-width: 75ch; }

footer { padding: 2rem 0 3rem; color: var(--faint); font-size: .85rem; }
footer .wrap { display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap; }

@media (max-width: 860px) {
  .hero .grid { grid-template-columns: 1fr; gap: 2rem; }
  .hero .cover { max-width: 240px; }
  .chain { grid-template-columns: 1fr; }
  .chain > div + div { border-left: 0; border-top: 1.5px solid var(--ink); }
  .chain > div + div::before { content: "↓"; left: 1.2rem; top: -.85rem; }
  .around, .results, .toc, .examples { grid-template-columns: 1fr; }
  .aud { grid-template-columns: 1fr 1fr; }
  .calc { grid-template-columns: 1fr; padding: 1.1rem; }
  .readout { grid-template-columns: 1fr 1fr; }
  section { padding: 3rem 0; }
}
@media (max-width: 520px) {
  .aud { grid-template-columns: 1fr; }
  .nav .links { margin-left: 0; gap: .8rem; }
}