/* Tokens ---------------------------------------------------------------- */
:root {
  --bg: #f7f6f2;
  --surface: #efede6;
  --text: #16171a;
  --muted: #55575d;
  --line: #d6d3c8;
  --accent: #a83c06;
  --accent-soft: #f6e3d6;
  --focus: #1f4fd1;

  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", "Cascadia Code", "JetBrains Mono", Menlo, Consolas, monospace;

  --step--1: clamp(0.875rem, 0.85rem + 0.1vw, 0.9375rem);
  --step-0: clamp(1rem, 0.97rem + 0.15vw, 1.0625rem);
  --step-1: clamp(1.25rem, 1.15rem + 0.4vw, 1.5rem);
  --step-2: clamp(1.75rem, 1.4rem + 1.4vw, 2.5rem);
  --step-3: clamp(2.25rem, 1.6rem + 2.8vw, 4rem);

  --gutter: clamp(1rem, 0.6rem + 2vw, 2.5rem);
  --radius: 0.375rem;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e0f10;
    --surface: #17191b;
    --text: #ecebe6;
    --muted: #a4a49e;
    --line: #2e3136;
    --accent: #ff9a57;
    --accent-soft: #2a1a10;
    --focus: #8fb4ff;
  }
}

/* Base ------------------------------------------------------------------ */
*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 1.5rem;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 400 var(--step-0)/1.6 var(--sans);
  font-kerning: normal;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, p, ul, ol { margin: 0; }
ul, ol { padding: 0; list-style: none; }

a {
  color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.2em;
  transition: text-decoration-thickness 150ms ease-out;
}
a:hover { text-decoration-thickness: 2px; }

:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 3px;
  border-radius: 2px;
}
main:focus { outline: none; }

abbr[title] { text-decoration: underline dotted; cursor: help; }

.skip {
  position: absolute;
  left: 1rem;
  top: -100px;
  z-index: 10;
  padding: 0.75rem 1rem;
  background: var(--text);
  color: var(--bg);
  border-radius: var(--radius);
}
.skip:focus { top: 1rem; }

/* Layout ---------------------------------------------------------------- */
.shell {
  max-width: 76rem;
  margin: 0 auto;
  padding: var(--gutter);
  display: grid;
  gap: clamp(3rem, 2rem + 4vw, 5rem);
}

@media (min-width: 64rem) {
  .shell {
    grid-template-columns: minmax(18rem, 25rem) minmax(0, 1fr);
    gap: 5rem;
    align-items: start;
  }
}
/* Stick only when the whole intro fits, so nothing is ever cut off. */
@media (min-width: 64rem) and (min-height: 56rem) {
  .intro { position: sticky; top: var(--gutter); }
}

/* Intro ----------------------------------------------------------------- */
.intro { display: grid; gap: 1.25rem; align-content: start; padding-top: 0.5rem; }

.intro-top { display: flex; justify-content: space-between; align-items: flex-start; gap: 1rem; }

.portrait {
  display: block;
  width: clamp(5.5rem, 4.5rem + 3vw, 7.5rem);
  height: auto;
  aspect-ratio: 1;
  object-fit: cover;
  border-radius: 1rem;
  background: var(--surface);
}

.lang {
  display: inline-flex;
  align-items: center;
  min-height: 2.75rem;
  padding-inline: 0.875rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--text);
  text-decoration: none;
  font: 500 var(--step--1)/1 var(--mono);
  transition: border-color 150ms ease-out;
}
.lang:hover { border-color: var(--text); }

.mark {
  font: 600 var(--step--1)/1 var(--mono);
  letter-spacing: 0.02em;
  color: var(--muted);
}
.mark span { color: var(--accent); }

h1 {
  font-size: var(--step-3);
  font-weight: 750;
  line-height: 1.02;
  letter-spacing: -0.035em;
  text-wrap: balance;
  overflow-wrap: anywhere;
  hyphens: manual;
}

.role {
  font: 500 var(--step--1)/1.4 var(--mono);
  color: var(--muted);
}

.lede { font-size: var(--step-1); line-height: 1.45; max-width: 34ch; text-wrap: pretty; }

.toc { display: flex; flex-wrap: wrap; gap: 0.25rem 1.25rem; margin-top: 0.5rem; }
.toc a,
.links a {
  display: inline-flex;
  align-items: center;
  min-height: 2.75rem;
  font: 500 var(--step--1)/1 var(--mono);
}
.toc a { color: var(--text); }

.links { display: flex; flex-wrap: wrap; gap: 0 1.25rem; padding-top: 1rem; border-top: 1px solid var(--line); }


/* Sections -------------------------------------------------------------- */
main { display: grid; gap: clamp(4rem, 3rem + 4vw, 7rem); padding-top: 0.5rem; }
section { display: grid; gap: 1.75rem; }

h2 {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  font-size: var(--step-2);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.1;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--line);
}
.idx { font: 500 var(--step--1)/1 var(--mono); color: var(--accent); letter-spacing: 0; }

.section-lede { color: var(--muted); max-width: 60ch; margin-top: -0.75rem; }

h3 { font-size: var(--step-0); font-weight: 650; line-height: 1.35; }
h4 { font-size: var(--step-0); font-weight: 600; line-height: 1.35; }

.sub {
  margin-top: 1rem;
  font: 600 var(--step--1)/1 var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
}

/* Focus ----------------------------------------------------------------- */
.focus {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}
@media (min-width: 40rem) { .focus { grid-template-columns: 1fr 1fr; } }

.focus li {
  background: var(--bg);
  padding: clamp(1.25rem, 1rem + 1vw, 1.75rem);
  display: grid;
  gap: 0.5rem;
  align-content: start;
}
.focus p { color: var(--muted); max-width: 60ch; }

/* Strata ---------------------------------------------------------------- */
.strata { display: grid; border-top: 1px solid var(--line); }

.layer {
  display: grid;
  gap: 0.75rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--line);
}
@media (min-width: 40rem) {
  .layer { grid-template-columns: 10rem 1fr; align-items: baseline; gap: 1.5rem; }
}
.layer h3 {
  font: 600 var(--step--1)/1.4 var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
}
.layer--core { background: linear-gradient(90deg, var(--accent-soft), transparent 70%); padding-inline: 0.75rem; margin-inline: -0.75rem; border-radius: var(--radius); border-bottom: 0; }
.layer--core h3 { color: var(--accent); }

.chips { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.chips li {
  padding: 0.25rem 0.625rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  font-size: var(--step--1);
  line-height: 1.5;
}

.concepts { display: flex; flex-wrap: wrap; gap: 0.5rem 1.5rem; }
.concepts li { display: flex; align-items: baseline; gap: 0.5rem; }
.concepts li::before { content: "→"; color: var(--accent); font-family: var(--mono); }

/* Timeline -------------------------------------------------------------- */
.timeline > li,
.nested > li {
  display: grid;
  gap: 0.25rem 1.5rem;
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--line);
}
.timeline > li:first-child { padding-top: 0; }
@media (min-width: 40rem) {
  .timeline > li { grid-template-columns: 8rem 1fr; }
  .nested > li { grid-template-columns: 6.5rem 1fr; }
}

.when {
  font: 500 var(--step--1)/1.6 var(--mono);
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.timeline p:not(.when) { color: var(--muted); max-width: 62ch; }
.timeline .at { font-weight: 400; color: var(--muted); }

.nested {
  margin-top: 1rem;
  padding-left: 1rem;
  border-left: 2px solid var(--accent);
}
.nested > li { padding: 0.75rem 0; }
.nested > li:last-child { border-bottom: 0; padding-bottom: 0; }
.nested > li:first-child { padding-top: 0; }

.plain { display: grid; gap: 0.625rem; }
.plain li { max-width: 70ch; }

/* Contact --------------------------------------------------------------- */
.big { font-size: var(--step-2); font-weight: 650; letter-spacing: -0.02em; line-height: 1.2; text-wrap: balance; overflow-wrap: anywhere; }

/* Footer ---------------------------------------------------------------- */
.foot {
  max-width: 76rem;
  margin: 0 auto;
  padding: 2rem var(--gutter) 3rem;
  color: var(--muted);
  font-size: var(--step--1);
}

/* Motion ---------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; }
}

@media print {
  .intro { position: static; min-height: 0; }
  .toc, .skip { display: none; }
  a { color: inherit; }
}