:root {
  color-scheme: dark;
  --bg: #0f0f1a;
  --surface: #1a1a2e;
  --border: #2d2d4e;
  --text: #e8e8f0;
  --muted: #b9b9d4;
  --dim: #9292b8;
  --accent: #6aabf5;
  --accent-strong: #4995ec;
  --pink: #ef6a92;
  --radius: 14px;
  --measure: 760px;
}

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

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

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(1100px 520px at 50% -12%, rgb(73 149 236 / 12%), transparent 62%), var(--bg);
  color: var(--text);
  font:
    16px / 1.65 ui-sans-serif,
    system-ui,
    -apple-system,
    "Segoe UI",
    roboto,
    helvetica,
    arial,
    sans-serif;
}

::selection {
  background: rgb(73 149 236 / 35%);
}

a {
  color: var(--accent);
  text-underline-offset: 3px;
}

a:hover {
  color: #9ac8ff;
}

a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

.site-header {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  max-width: var(--measure);
  margin: 0 auto;
  padding: 24px 20px 0;
}

.brand {
  color: var(--text);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.01em;
  text-decoration: none;
}

.brand:hover {
  color: var(--text);
}

.brand .o {
  color: var(--pink);
}

.brand .x {
  color: var(--accent-strong);
}

.site-header nav {
  display: flex;
  gap: 18px;
  font-size: 14px;
}

main {
  max-width: var(--measure);
  margin: 0 auto;
  padding: 32px 20px 64px;
}

h1 {
  margin: 0 0 10px;
  font-size: clamp(28px, 5vw, 40px);
  line-height: 1.15;
}

h2 {
  margin: 38px 0 8px;
  font-size: 21px;
  line-height: 1.3;
}

h3 {
  margin: 26px 0 6px;
  font-size: 16px;
  line-height: 1.35;
}

p {
  margin: 0 0 14px;
}

ul {
  margin: 0 0 14px;
  padding-left: 22px;
}

li {
  margin: 6px 0;
}

li::marker {
  color: var(--muted);
}

strong {
  color: var(--text);
}

.lede {
  margin-bottom: 22px;
  color: var(--muted);
  font-size: 18px;
}

.meta {
  margin-bottom: 24px;
  color: var(--dim);
  font-size: 13px;
}

.note,
.card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
}

.note {
  margin: 18px 0;
  padding: 14px 16px;
  color: var(--muted);
}

.card {
  margin: 18px 0;
  padding: 4px 20px 14px;
}

.card h2 {
  margin-top: 18px;
}

.lang-nav {
  display: flex;
  gap: 8px;
  margin: 0 0 10px;
  font-size: 14px;
}

footer a {
  color: var(--muted);
}

.lang-nav a {
  padding: 4px 12px;
  border: 1px solid var(--border);
  border-radius: 999px;
  text-decoration: none;
}

.lang-nav a:hover {
  border-color: var(--accent);
}

details {
  margin: 0 0 10px;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
}

details summary {
  cursor: pointer;
  color: var(--text);
  font-weight: 600;
}

details summary::marker {
  color: var(--accent);
}

details p {
  margin: 10px 0 0;
  color: var(--muted);
}

hr {
  margin: 48px 0;
  border: 0;
  border-top: 1px solid var(--border);
}

code {
  padding: 1px 5px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface);
  font-family: ui-monospace, sfmono-regular, menlo, consolas, monospace;
  font-size: 0.9em;
}

footer {
  max-width: var(--measure);
  margin: 0 auto;
  padding: 0 20px 48px;
  color: var(--dim);
  font-size: 13px;
}

@media (max-width: 480px) {
  .site-header {
    padding-top: 18px;
  }

  .site-header nav {
    gap: 12px;
  }

  main {
    padding-top: 24px;
  }
}

@media print {
  :root {
    color-scheme: light;
  }

  body {
    background: #fff;
    color: #111;
  }

  a,
  .brand,
  .brand:hover {
    color: #111;
  }

  .site-header nav,
  .lang-nav {
    display: none;
  }

  details {
    border-color: #ccc;
    background: #fff;
  }
}