:root {
  font-family: system-ui, sans-serif;
  color: #172633;
  background: #f6f8fb;
  line-height: 1.65;
  color-scheme: light dark;
}

* {
  box-sizing: border-box;
}
body {
  margin: 0;
}
header,
main {
  max-width: 54rem;
  margin: auto;
  padding: 1.5rem;
}
header {
  display: flex;
  align-items: center;
  gap: 1rem;
  border-bottom: 1px solid #a3b1be;
}
header a {
  font-weight: 700;
}
main {
  padding-bottom: 4rem;
}
h1,
h2,
dt {
  line-height: 1.3;
}
h1 {
  font-size: clamp(1.8rem, 5vw, 2.6rem);
  margin-top: 0.5rem;
}
h2 {
  font-size: 1.4rem;
  margin-top: 2.5rem;
  scroll-margin-top: 1rem;
}
a {
  color: #174ba6;
  text-underline-offset: 0.2em;
}
nav {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr));
  gap: 0.25rem 1.5rem;
  margin: 1.5rem 0 2rem;
}
nav a,
header a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
}
a:focus-visible {
  outline: 3px solid currentColor;
  outline-offset: 3px;
  border-radius: 2px;
}
.intro {
  font-size: 1.15rem;
}
dt {
  margin-top: 1.5rem;
  font-weight: 700;
}
dd {
  margin: 0.5rem 0 0;
}
.return-note {
  border-top: 1px solid #a3b1be;
  margin-top: 2rem;
  padding-top: 1rem;
}
.skip-link {
  position: absolute;
  top: -10rem;
  left: 1rem;
  padding: 0.75rem;
  background: #f6f8fb;
}
.skip-link:focus {
  top: 0.5rem;
}
@media (prefers-color-scheme: dark) {
  :root {
    color: #ecf1f7;
    background: #151b23;
  }
  a {
    color: #a8c8ff;
  }
  .skip-link {
    background: #151b23;
  }
}