:root {
  color-scheme: light dark;
  --teal: #275561;
  --teal-strong: #1d424c;
  --header-grad-a: #1e434c;
  --header-grad-b: #2f6672;
  --white-glyph: #f5f5f5;
  --paper: #faf9f6;
  --surface: #ffffff;
  --ink: #1b1f1e;
  --muted: #5c6663;
  --accent: var(--teal);
  --border: rgba(27, 31, 30, 0.14);
  --font-body: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --header-grad-a: #234c56;
    --header-grad-b: #3c7986;
    --paper: #0e2126;
    --surface: #163138;
    --ink: #f1f4f3;
    --muted: #9fb4b1;
    --accent: #7fb8c4;
    --border: rgba(255, 255, 255, 0.14);
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 16px/1.6 var(--font-body);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration-color: var(--border);
  text-underline-offset: 2px;
}

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

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

/* letterhead bar */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.6rem 1.25rem;
  max-width: 44rem;
  margin: 1.5rem auto 0;
  padding: 0.85rem 1.1rem;
  background: linear-gradient(135deg, var(--header-grad-a), var(--header-grad-b));
  border-radius: 10px;
}

.wordmark {
  display: inline-flex;
  align-items: center;
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--white-glyph);
  text-decoration: none;
}

.mark {
  display: inline-block;
  width: 26px;
  height: 26px;
  margin-right: 9px;
  border-radius: 7px;
  border: 1px solid rgba(245, 245, 245, 0.2);
  vertical-align: middle;
}

.site-nav {
  display: flex;
  gap: 1.1rem;
  font-size: 0.88rem;
}

.site-nav a {
  color: rgba(245, 245, 245, 0.72);
  text-decoration: none;
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
}

.site-nav a:hover {
  color: var(--white-glyph);
}

.site-nav a.active {
  color: var(--white-glyph);
  border-bottom-color: var(--white-glyph);
}

.site-nav a:focus-visible {
  outline-color: var(--white-glyph);
}

main {
  max-width: 44rem;
  margin: 0 auto;
  padding: 2rem 1.25rem 4rem;
}

.eyebrow {
  display: block;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.5rem;
}

h1 {
  font-size: 1.9rem;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
  margin: 0 0 0.75rem;
}

h2 {
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.3;
  margin: 2rem 0 0.75rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
}

.card h2 {
  border-top: none;
  padding-top: 0;
  margin-top: 0;
}

h3 {
  font-size: 0.98rem;
  font-weight: 700;
  margin: 1.5rem 0 0.5rem;
}

p,
li {
  margin: 0.75rem 0;
  color: var(--ink);
}

.updated,
.intro {
  color: var(--muted);
}

.updated {
  font-size: 0.9rem;
}

ul,
ol {
  padding-left: 1.3rem;
}

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

code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--border);
  padding: 0.1em 0.35em;
  border-radius: 4px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.5rem 1.5rem 1.75rem;
  margin: 1.5rem 0;
}

.card-head {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 0.25rem;
}

.card-head h2 {
  margin: 0;
}

.chip {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--white-glyph);
  background: var(--teal);
  border-radius: 4px;
  padding: 0.15rem 0.4rem;
}

article.doc {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.75rem 1.75rem 2rem;
}

.page-footer {
  max-width: 44rem;
  margin: 0 auto;
  padding: 0 1.25rem 3rem;
  color: var(--muted);
  font-size: 0.85rem;
}

@media (max-width: 30rem) {
  article.doc,
  .card {
    padding: 1.25rem;
  }

  h1 {
    font-size: 1.6rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
  }
}