:root {
  color-scheme: light;
  --paper: #f3f1e9;
  --ink: #202d35;
  --muted: #667477;
  --line: #d7ddd7;
  --blue: #245de0;
  --mint: #e7f0e9;
  --green: #27724d;
  --orange: #a84723;
  --white: #fffefa;
  --radius: 18px;
  --font-body: 'Trebuchet MS', Verdana, sans-serif;
  --font-title: Georgia, serif;
  --shadow: 0 8px 30px #23362c06;
}

* { box-sizing: border-box; }
html { background: var(--paper); }
body.lab {
  margin: 0;
  color: var(--ink);
  font: 16px/1.55 var(--font-body);
  background: radial-gradient(ellipse at 90% 0%, #dfebeb 0, transparent 42%), var(--paper);
}
.lab :where(button, input, select) { font: inherit; }
.lab button { cursor: pointer; }
.lab a { color: inherit; }
.lab button, .lab a, .lab input, .lab select { -webkit-tap-highlight-color: transparent; }
.lab :is(button, a, input, select, [tabindex]):focus-visible {
  outline: 3px solid var(--blue);
  outline-offset: 4px;
}
.lab h1 {
  font: normal clamp(40px, 5vw, 70px)/1.08 var(--font-title);
  letter-spacing: -2px;
  margin: 0 0 20px;
}
.lab :is(h2, h3, p) { margin-top: 0; }
.lab .eyebrow { font: bold 11px/1.4 var(--font-body); letter-spacing: 1.4px; color: var(--green); margin: 0 0 12px; }
.lab .lab-shell { max-width: 1240px; margin: auto; padding: 0 32px; }
.lab .lab-intro { display: flex; justify-content: space-between; align-items: center; gap: 32px; padding: 56px 0 42px; }
.lab .lab-lede { font-size: 18px; line-height: 1.55; color: var(--muted); margin: 0; max-width: 760px; }
.lab-header {
  position: relative;
  z-index: 1;
  max-width: 1320px;
  margin: auto;
  padding: 24px 40px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  border-bottom: 1px solid var(--line);
}
.lab-brand { display: flex; align-items: center; gap: 12px; text-decoration: none; font-size: 14px; font-weight: bold; }
.lab-mark { background: var(--ink); color: #c5efdc; border-radius: 10px; padding: 9px 8px; letter-spacing: -2px; font-size: 18px; }
.lab-brand small { color: var(--muted); font-size: 12px; font-weight: normal; }
.lab-links { display: flex; gap: 6px; flex-wrap: wrap; }
.lab-links a { padding: 8px 13px; border: 1px solid transparent; border-radius: 8px; text-decoration: none; font-size: 13px; }
.lab-links a:hover { border-color: var(--line); }
.lab-links a[aria-current=page] { background: var(--ink); color: var(--white); }
.lab .lab-chapters { display: grid; gap: 8px; margin: 0 0 16px; }
.lab .lab-chapters > :is(a, button) {
  display: flex;
  align-items: center;
  gap: 13px;
  min-width: 0;
  padding: 17px 16px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fff8;
  color: var(--ink);
  font: 14px/1.4 var(--font-body);
  text-decoration: none;
  text-align: left;
}
.lab .lab-chapters > :is(a, button) span { color: var(--muted); font: 12px monospace; }
.lab .lab-chapters > :is([aria-current=page], .is-active) { background: var(--ink); color: var(--white); border-color: var(--ink); }
.lab .lab-chapters > :is([aria-current=page], .is-active) span { color: #a8d5c3; }
.lab.embedded .lab-header { display: none; }
.lab.embedded .lab-shell { padding: 0 20px; }
.lab.embedded .lab-intro { padding-top: 28px; }
@media (max-width: 900px) {
  .lab .lab-chapters > :is(a, button) { font-size: 12px; padding: 13px 10px; gap: 8px; }
}
@media (max-width: 650px) {
  .lab-header { padding: 16px; flex-wrap: wrap; gap: 12px; }
  .lab-brand { font-size: 12px; gap: 8px; }
  .lab-links { width: 100%; }
  .lab-links a { flex: 1; text-align: center; }
  .lab .lab-shell { padding: 0 16px; }
  .lab .lab-intro { display: block; padding: 30px 0 24px; }
  .lab h1 { font-size: 43px; }
  .lab .lab-lede { font-size: 16px; }
  .lab .lab-chapters { grid-template-columns: 1fr 1fr; }
  .lab .lab-chapters > :is(a, button) { padding: 13px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}