:root {
  color-scheme: light dark;
  --accent: #2b2722;
  --on-accent: #ffffff;
  --mark: #ffc800;
  --highlight: #fdf2cc;
  --ground: #f2f2f7;
  --row: #ffffff;
  --ink: #000000;
  /* 0.72 composites to 4.47:1 on --ground, just below WCAG AA for body text. */
  --ink-2: rgba(60, 60, 67, 0.76);
  --separator: rgba(60, 60, 67, 0.18);
  --radius: 10px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --accent: #efeadf;
    --on-accent: #1c1b18;
    --highlight: #3d382a;
    --ground: #1c1c1e;
    --row: #2c2c2e;
    --ink: #ffffff;
    --ink-2: rgba(235, 235, 245, 0.72);
    --separator: rgba(84, 84, 88, 0.65);
  }
}

* {
  box-sizing: border-box;
}

html {
  -webkit-text-size-adjust: 100%;
}

body {
  display: flex;
  flex-direction: column;
  min-height: 100dvh;
  margin: 0;
  background: var(--ground);
  color: var(--ink);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 1rem;
  line-height: 1.6;
}

a {
  color: inherit;
  text-underline-offset: 0.2em;
  text-decoration-thickness: 1px;
}

a:hover {
  text-decoration-thickness: 2px;
}

a:focus-visible {
  border-radius: 3px;
  outline: 3px solid var(--accent);
  outline-offset: 3px;
}

.site-header,
.site-footer,
.page {
  width: min(100% - 2rem, 52rem);
  margin-inline: auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 4.5rem;
}

.wordmark {
  font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, monospace;
  font-size: 1.05rem;
  font-weight: 650;
  letter-spacing: -0.03em;
  text-decoration: none;
}

.site-nav {
  display: flex;
  gap: 1rem;
  color: var(--ink-2);
  font-size: 0.9rem;
}

.site-nav a[aria-current="page"] {
  color: var(--ink);
  font-weight: 600;
  text-decoration: none;
}

.page {
  padding-block: clamp(3.5rem, 12vh, 8rem);
}

/* main grows into whatever the header and footer leave, so a one-screen page centres
   itself without subtracting their heights. Guessed heights were wrong by up to 23px
   and the 404 scrolled. */
main {
  flex: 1 0 auto;
}

/* One-screen pages only. The homepage scrolls now, and centring its first section in
   the viewport left no hint that anything followed it. */
.centered {
  display: grid;
  align-content: center;
  max-width: 44rem;
  padding-block: 2rem;
}

.home {
  padding-block: 0 clamp(3rem, 8vh, 5rem);
}

.section {
  width: min(100% - 2rem, 52rem);
  margin-inline: auto;
  padding-block: clamp(2.75rem, 7vh, 4rem);
  border-top: 1px solid var(--separator);
}

.section:first-child {
  border-top: 0;
}

.hero {
  padding-block: clamp(2rem, 7vh, 4rem) clamp(2.75rem, 7vh, 4rem);
}

.section h2 {
  margin: 0 0 2rem;
  color: var(--ink-2);
  font-size: 0.82rem;
  font-weight: 650;
  letter-spacing: 0.09em;
  line-height: 1.4;
  text-transform: uppercase;
}

.status {
  display: inline-block;
  justify-self: start;
  margin: 0 0 1.5rem;
  padding: 0.35rem 0.65rem;
  border-radius: 999px;
  background: var(--mark);
  color: #17150f;
  font-size: 0.82rem;
  font-weight: 650;
}

h1,
h2 {
  letter-spacing: -0.035em;
  line-height: 1.12;
}

h1 {
  max-width: 17ch;
  margin: 0;
  font-size: clamp(2.25rem, 6.5vw, 4.25rem);
  font-weight: 700;
}

.lede {
  max-width: 34rem;
  margin: 1.75rem 0 0;
  color: var(--ink-2);
  font-size: clamp(1.1rem, 2.5vw, 1.35rem);
  line-height: 1.5;
}

/* A section that opens with a sentence wants its label sitting closer to it. */
.section:has(.section-intro) h2 {
  margin-bottom: 0.85rem;
}

.section-intro {
  max-width: 48ch;
  margin: 0 0 2.25rem;
  color: var(--ink-2);
  font-size: 1.05rem;
}

.steps,
.reasons {
  display: grid;
  margin: 0;
  padding: 0;
  list-style: none;
}

.steps {
  counter-reset: step;
  gap: 2rem;
}

.steps > li {
  display: grid;
  grid-template-columns: 2rem 1fr;
  column-gap: 1rem;
  row-gap: 0.35rem;
  counter-increment: step;
}

.steps > li::before {
  content: counter(step);
  display: grid;
  grid-area: 1 / 1 / span 2 / span 1;
  place-items: center;
  width: 2rem;
  height: 2rem;
  border-radius: 999px;
  background: var(--mark);
  color: #17150f;
  font-size: 0.95rem;
  font-weight: 650;
  line-height: 1;
}

.steps > li h3 {
  grid-area: 1 / 2;
}

.steps > li p {
  grid-area: 2 / 2;
}

.reasons {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2rem 2.5rem;
}

.steps h3,
.reasons h3 {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 650;
  letter-spacing: -0.01em;
  line-height: 1.35;
}

.steps p,
.reasons p {
  max-width: 44ch;
  margin: 0;
  color: var(--ink-2);
}

.reasons p {
  margin-top: 0.35rem;
}

.cta-line {
  margin: 0;
  font-size: clamp(1.5rem, 4.5vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.03em;
}

.document {
  max-width: 46rem;
  padding-block-start: 3rem;
}

.document h1 {
  max-width: none;
  font-size: clamp(2.25rem, 7vw, 4rem);
}

.updated {
  margin: 0.75rem 0 3rem;
  color: var(--ink-2);
  font-size: 0.9rem;
  font-variant-numeric: tabular-nums;
}

.document h2 {
  margin: 2.75rem 0 0.75rem;
  font-size: 1.35rem;
}

.document p,
.document li {
  max-width: 68ch;
}

.document ul {
  padding-left: 1.4rem;
}

.document li + li {
  margin-top: 0.5rem;
}

.callout {
  margin: 2rem 0;
  padding: 1rem 1.1rem;
  border-left: 3px solid var(--mark);
  background: var(--highlight);
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding-block: 1.5rem 2rem;
  border-top: 1px solid var(--separator);
  color: var(--ink-2);
  font-size: 0.85rem;
}

.site-footer p {
  margin: 0;
}

.footer-copy {
  display: grid;
  gap: 0.45rem;
}

.art-credit {
  max-width: 37rem;
  font-size: 0.75rem;
}

.site-footer nav {
  display: flex;
  gap: 1rem;
}

@media (max-width: 48rem) {
  .reasons {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (max-width: 34rem) {
  .site-header,
  .site-footer {
    align-items: flex-start;
    flex-direction: column;
    justify-content: center;
  }

  .site-header {
    padding-block: 1rem;
  }

  .site-nav {
    flex-wrap: wrap;
  }

  .page {
    padding-block: 3rem 5rem;
  }

  .centered {
    padding-block: 2rem;
  }

  .section h2 {
    margin-bottom: 1.5rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
  }
}