:root {
  color-scheme: light dark;
  --bg: #f6f7f9;
  --band: #eef1f5;
  --fg: #1b1d21;
  --muted: #5b6270;
  --card: #ffffff;
  --line: #dde1e7;
  --accent: #0b6bcb;
  --accent-fg: #ffffff;
  --observed: #1f6f43;
  --derived: #1d4f91;
  --hypothesis: #8a5a00;
  --unknown: #5f6368;
  --ok: #1e7a46;
  --wait: #8a5a00;
  --no: #b42318;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121417;
    --band: #181b1f;
    --fg: #e9ebee;
    --muted: #a6acb7;
    --card: #1d2025;
    --line: #2f343c;
    --accent: #5aa2f0;
    --accent-fg: #0b1220;
    --observed: #5cc28a;
    --derived: #7aa7e8;
    --hypothesis: #e0b455;
    --unknown: #a3a8b0;
    --ok: #5ccf8f;
    --wait: #e2b45c;
    --no: #f2877c;
  }
}
* {
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
}
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font:
    17px/1.6 -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    Roboto,
    "Helvetica Neue",
    Arial,
    sans-serif;
}
a {
  color: var(--accent);
}
a:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}
code,
pre {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}
code {
  font-size: 0.9em;
}
.wrap {
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 20px;
}
.skip {
  position: absolute;
  left: -9999px;
  top: 8px;
  background: var(--card);
  padding: 8px 12px;
  z-index: 10;
}
.skip:focus {
  left: 12px;
}

.top {
  position: sticky;
  top: 0;
  z-index: 5;
  background: color-mix(in srgb, var(--bg) 92%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.top-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 60px;
  flex-wrap: wrap;
  padding-top: 8px;
  padding-bottom: 8px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--fg);
  text-decoration: none;
  font-weight: 700;
}
.brand-by {
  font-weight: 500;
  color: var(--muted);
}
.logo {
  width: 34px;
  height: 34px;
  border-radius: 9px;
  background: var(--accent);
  color: var(--accent-fg);
  display: grid;
  place-items: center;
  font-size: 0.85rem;
  font-weight: 800;
}
nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 4px 16px;
}
nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.95rem;
}
nav a:hover {
  color: var(--fg);
}

.hero {
  padding: 72px 0 56px;
}
h1 {
  font-size: clamp(2rem, 5vw, 3.1rem);
  line-height: 1.15;
  margin: 0 0 16px;
  letter-spacing: -0.01em;
}
h1 span {
  display: block;
  color: var(--muted);
  font-weight: 600;
  font-size: 0.62em;
  margin-top: 6px;
}
.lead {
  font-size: 1.2rem;
  max-width: 760px;
  color: var(--fg);
  margin: 0 0 28px;
}
.cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 32px;
}
.button {
  display: inline-block;
  padding: 11px 18px;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--fg);
  text-decoration: none;
  font-weight: 600;
}
.button.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-fg);
}
.facts {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 10px;
}
.facts li {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 10px 14px;
  font-weight: 600;
  font-size: 0.95rem;
}

section {
  padding: 56px 0;
  scroll-margin-top: 64px;
}
.band {
  background: var(--band);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}
h2 {
  font-size: 1.7rem;
  margin: 0 0 20px;
}
h3 {
  font-size: 1.15rem;
  margin: 28px 0 10px;
}
.note,
.muted {
  color: var(--muted);
}
.note {
  font-size: 0.95rem;
}

.steps {
  counter-reset: step;
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
}
.steps li {
  counter-increment: step;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 16px;
}
.steps li::before {
  content: counter(step);
  display: inline-grid;
  place-items: center;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: var(--accent);
  color: var(--accent-fg);
  font-weight: 700;
  font-size: 0.9rem;
  margin-bottom: 8px;
}
.steps li strong {
  display: block;
  font-size: 1.05rem;
  margin-bottom: 2px;
}

.classes {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
  margin: 0 0 16px;
}
.classes div {
  background: var(--card);
  border: 1px solid var(--line);
  border-left: 4px solid var(--c);
  border-radius: 10px;
  padding: 12px 14px;
}
.classes dt {
  font-weight: 700;
  color: var(--c);
}
.classes dd {
  margin: 4px 0 0;
}
.observed {
  --c: var(--observed);
}
.derived {
  --c: var(--derived);
}
.hypothesis {
  --c: var(--hypothesis);
}
.unknown {
  --c: var(--unknown);
}

.table-scroll {
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--card);
}
table {
  border-collapse: collapse;
  width: 100%;
  min-width: 640px;
}
caption {
  text-align: left;
  padding: 12px 16px;
  color: var(--muted);
  font-size: 0.95rem;
}
th,
td {
  text-align: left;
  vertical-align: top;
  padding: 12px 16px;
  border-top: 1px solid var(--line);
}
thead th {
  font-size: 0.9rem;
  color: var(--muted);
}
tbody th {
  font-weight: 700;
  width: 24%;
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 20px;
}
.card h3 {
  margin-top: 0;
}

.checks {
  list-style: none;
  padding: 0;
  margin: 0 0 16px;
  display: grid;
  gap: 10px;
}
.checks li {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 12px 14px;
}

.systems {
  padding-left: 20px;
}
.systems li {
  margin: 6px 0;
}
.tag {
  display: inline-block;
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  padding: 1px 8px;
  border-radius: 999px;
  border: 1px solid currentColor;
  margin-right: 6px;
}
.tag.ok {
  color: var(--ok);
}
.tag.wait {
  color: var(--wait);
}
.tag.no {
  color: var(--no);
}

pre {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 14px 16px;
  overflow-x: auto;
  font-size: 0.88rem;
  line-height: 1.5;
}

details {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0 16px;
  margin: 0 0 10px;
}
summary {
  cursor: pointer;
  padding: 14px 0;
  font-weight: 600;
}
details p {
  margin: 0 0 14px;
}

.links {
  padding-left: 20px;
}
.bottom {
  padding: 28px 0 40px;
  color: var(--muted);
  font-size: 0.9rem;
}
.bottom p {
  margin: 4px 0;
}

@media (max-width: 640px) {
  body {
    font-size: 16px;
  }
  .hero {
    padding: 44px 0 36px;
  }
  section {
    padding: 40px 0;
  }
  nav ul {
    gap: 2px 12px;
  }
  .top {
    position: static;
  }
  .table-scroll {
    border: 0;
    background: none;
  }
  table,
  caption,
  tbody,
  tr,
  th,
  td {
    display: block;
    min-width: 0;
    width: 100%;
  }
  thead {
    display: none;
  }
  caption {
    padding: 0 0 10px;
  }
  tbody tr {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 12px;
    margin-bottom: 12px;
  }
  tbody th {
    width: auto;
    border-top: 0;
    padding-bottom: 4px;
  }
  td {
    padding-top: 6px;
    padding-bottom: 10px;
  }
  td::before {
    content: attr(data-label);
    display: block;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--muted);
  }
  section {
    scroll-margin-top: 0;
  }
}