:root {
  color-scheme: dark;
  --background: #101820;
  --surface: #17232d;
  --text: #e8eef0;
  --muted: #a4b1b7;
  --line: #33434d;
  --accent: #f0c967;
  --cyan: #86d2d0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  max-width: 960px;
  min-width: 320px;
  margin: 0 auto;
  padding: 0 24px;
  color: var(--text);
  background: var(--background);
  font-size: 16px;
  line-height: 1.65;
}

a {
  color: var(--accent);
}

a:hover,
a:focus-visible {
  color: var(--cyan);
}

.site-header {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 32px;
  padding: 48px 0 32px;
  border-bottom: 1px solid var(--line);
}

.eyebrow,
.topic-nav-title,
.device-note strong,
.site-footer {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--cyan);
  font-size: 0.75rem;
}

h1,
h2 {
  margin: 0;
  font-weight: 600;
  line-height: 1.2;
}

h1 {
  font-size: clamp(2rem, 5vw, 3.25rem);
}

h2 {
  margin-bottom: 16px;
  color: var(--accent);
  font-size: 1.35rem;
}

.intro {
  margin: 10px 0 0;
  color: var(--muted);
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: 0.78rem;
  text-transform: uppercase;
}

main {
  display: grid;
  grid-template-columns: 190px minmax(0, 1fr);
  gap: 48px;
  padding: 36px 0 64px;
}

.topic-nav {
  align-self: start;
  position: sticky;
  top: 24px;
}

.topic-nav-title {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 0.72rem;
}

.topic-nav ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.topic-nav li + li {
  margin-top: 7px;
}

.topic-nav a {
  font-size: 0.9rem;
}

.help-content section {
  padding: 28px 0;
  border-top: 1px solid var(--line);
  scroll-margin-top: 24px;
}

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

.help-content p {
  margin: 0;
}

.help-content p + p {
  margin-top: 12px;
}

.note,
.device-note {
  color: var(--muted);
  font-size: 0.92rem;
}

.device-note strong {
  margin-right: 8px;
  color: var(--text);
  font-size: 0.72rem;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 24px 0 40px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.7rem;
}

@media (max-width: 720px) {
  body {
    padding: 0 16px;
  }

  .site-header {
    display: block;
    padding-top: 32px;
  }

  .site-nav {
    margin-top: 20px;
  }

  main {
    display: block;
    padding-top: 28px;
  }

  .topic-nav {
    position: static;
    margin-bottom: 32px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--line);
  }

  .topic-nav ul {
    columns: 2;
  }

  .topic-nav li + li {
    margin-top: 7px;
  }

  .site-footer {
    display: block;
  }

  .site-footer a {
    display: block;
    margin-top: 8px;
  }
}