:root {
  --ink: #111827;
  --ink-strong: #18181b;
  --muted: #4b5563;
  --faint: #9ca3af;
  --line: #e5e7eb;
  --paper: #ffffff;
  --paper-soft: #f9fafb;
  --tile: #404040;
  --signal: #10b981;
  --signal-ink: #047857;

  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --measure: 40rem;
  --gutter: clamp(1.25rem, 5vw, 2.5rem);
}

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

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font);
  font-size: 1.0625rem;
  line-height: 1.6;
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

a {
  color: var(--ink-strong);
  text-decoration-color: var(--signal);
  text-decoration-thickness: 2px;
  text-underline-offset: 0.2em;
}

a:hover {
  color: var(--signal-ink);
}

a:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 3px;
  border-radius: 2px;
}

.skip-link {
  position: absolute;
  left: var(--gutter);
  top: -3rem;
  padding: 0.5rem 0.75rem;
  background: var(--ink-strong);
  color: var(--paper);
}

.skip-link:focus {
  top: 0.75rem;
}

/* Header and footer */

.site-header,
.site-footer {
  max-width: 64rem;
  margin: 0 auto;
  padding: 1.25rem var(--gutter);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem 1.5rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.625rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  text-decoration: none;
}

.brand img {
  width: 2rem;
  height: 2rem;
  border-radius: 0.5rem;
}

.site-nav,
.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 0.9375rem;
}

.site-nav a,
.footer-links a {
  color: var(--muted);
  text-decoration: none;
}

.site-nav a:hover,
.footer-links a:hover,
.site-nav a[aria-current="page"] {
  color: var(--ink-strong);
}

.site-footer {
  margin-top: 5rem;
  padding-top: 2rem;
  padding-bottom: 2.5rem;
  border-top: 1px solid var(--line);
  color: var(--faint);
  font-size: 0.875rem;
}

.site-footer p {
  margin: 0;
}

/* Home */

.hero {
  max-width: 64rem;
  margin: 0 auto;
  padding: clamp(3rem, 10vw, 7rem) var(--gutter) clamp(2.5rem, 7vw, 4.5rem);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2.5rem;
  align-items: center;
}

.hero-mark {
  width: clamp(7rem, 22vw, 13rem);
  aspect-ratio: 1;
  border-radius: 22.5%;
  background: var(--tile);
  overflow: hidden;
}

.hero-mark img {
  width: 100%;
  height: 100%;
}

.hero h1 {
  margin: 0;
  max-width: 15em;
  color: var(--ink-strong);
  font-size: clamp(2.25rem, 6vw, 3.5rem);
  line-height: 1.08;
  letter-spacing: -0.025em;
  font-weight: 750;
}

.hero p {
  margin: 1.5rem 0 0;
  max-width: 34rem;
  color: var(--muted);
  font-size: clamp(1.0625rem, 2vw, 1.25rem);
}

.status {
  display: inline-flex;
  align-items: center;
  gap: 0.625rem;
  margin-top: 2rem;
  font-weight: 600;
  color: var(--ink-strong);
}

.status::before {
  content: "";
  width: 0.625rem;
  height: 0.625rem;
  border-radius: 50%;
  background: var(--signal);
}

.features {
  max-width: 64rem;
  margin: 0 auto;
  padding: 0 var(--gutter);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0 3rem;
}

.feature {
  padding: 1.75rem 0;
  border-top: 1px solid var(--line);
}

.feature h2 {
  margin: 0 0 0.5rem;
  color: var(--ink-strong);
  font-size: 1.25rem;
  letter-spacing: -0.015em;
}

.feature p {
  margin: 0;
  color: var(--muted);
}

.notice {
  max-width: 64rem;
  margin: 3rem auto 0;
  padding: 0 var(--gutter);
  color: var(--muted);
  font-size: 0.9375rem;
}

.notice p {
  max-width: var(--measure);
  margin: 0;
}

@media (min-width: 48rem) {
  .hero {
    grid-template-columns: auto minmax(0, 1fr);
    gap: 3.5rem;
  }

  .features {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* Documents */

.document {
  max-width: calc(var(--measure) + 2 * var(--gutter));
  margin: 0 auto;
  padding: clamp(2.5rem, 8vw, 4.5rem) var(--gutter) 0;
}

.document h1 {
  margin: 0;
  color: var(--ink-strong);
  font-size: clamp(2rem, 5vw, 2.75rem);
  line-height: 1.1;
  letter-spacing: -0.03em;
  font-weight: 800;
}

.updated {
  margin: 0.75rem 0 0;
  color: var(--faint);
  font-size: 0.9375rem;
}

.lead {
  margin: 2rem 0 0;
  font-size: 1.1875rem;
  color: var(--ink);
}

.document h2 {
  margin: 3rem 0 0.75rem;
  color: var(--ink-strong);
  font-size: 1.3125rem;
  line-height: 1.3;
  letter-spacing: -0.015em;
  scroll-margin-top: 1.5rem;
}

.document p,
.document ul,
.document ol {
  margin: 0.75rem 0 0;
}

.document ul,
.document ol {
  padding-left: 1.25rem;
}

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

.document li::marker {
  color: var(--faint);
}

.document strong {
  color: var(--ink-strong);
}

.contents {
  margin: 2.5rem 0 0;
  padding: 1.25rem 1.5rem;
  background: var(--paper-soft);
  border-radius: 0.875rem;
}

.contents p {
  margin: 0;
  font-weight: 600;
  color: var(--ink-strong);
}

.contents ol {
  margin: 0.75rem 0 0;
  columns: 2 14rem;
  column-gap: 2rem;
  font-size: 0.9375rem;
}

.contents li + li {
  margin-top: 0.25rem;
}

.contents a {
  color: var(--muted);
  text-decoration: none;
}

.contents a:hover {
  color: var(--ink-strong);
}

.callout {
  margin: 1rem 0 0;
  padding: 1rem 1.25rem;
  border-left: 3px solid var(--signal);
  background: var(--paper-soft);
}

.callout p:first-child {
  margin-top: 0;
}

/* Not found */

.not-found {
  max-width: 64rem;
  margin: 0 auto;
  padding: clamp(4rem, 14vw, 9rem) var(--gutter) 0;
}

.not-found h1 {
  margin: 0;
  color: var(--ink-strong);
  font-size: clamp(2rem, 5vw, 2.75rem);
  letter-spacing: -0.03em;
}

.not-found p {
  margin: 1rem 0 0;
  color: var(--muted);
}