/* Black text on white, with one red. */
:root {
  --ink: #000;
  --paper: #fff;
  --red: #d2001f;
  --rule: #e6e6e6;
  --code: #f4f4f4;
}

* { box-sizing: border-box; }

html { font-size: 112.5%; }

body {
  margin: 0;
  padding: 0 1.5rem 4rem;
  color: var(--ink);
  background: var(--paper);
  font-family: Georgia, "Iowan Old Style", "Palatino Linotype", "Book Antiqua", serif;
  line-height: 1.55;
  max-width: 44rem;
  margin-inline: auto;
}

header {
  padding-top: 4rem;
  border-bottom: 3px solid var(--ink);
  margin-bottom: 2.5rem;
}

h1 {
  font-size: 3.6rem;
  line-height: 1;
  letter-spacing: -0.03em;
  margin: 0 0 0.5rem;
  font-weight: 700;
}

.mark { color: var(--red); }

.tagline {
  font-size: 1.3rem;
  margin: 0 0 1.5rem;
}

nav {
  display: flex;
  gap: 1.5rem;
  padding-bottom: 0.75rem;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

a {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-color: var(--red);
  text-decoration-thickness: 2px;
  text-underline-offset: 0.15em;
}

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

nav a { text-decoration: none; }
nav a:hover, nav a:focus-visible { color: var(--red); }

section { margin-bottom: 2.5rem; }

h2 {
  font-size: 1.1rem;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin: 0 0 0.75rem;
}

h2::before {
  content: "";
  display: inline-block;
  width: 0.6em;
  height: 0.6em;
  background: var(--red);
  margin-right: 0.6em;
  vertical-align: baseline;
}

h3 {
  font-size: 0.85rem;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin: 1.25rem 0 0.25rem;
}

p { margin: 0 0 1rem; }

pre {
  background: var(--code);
  border-left: 3px solid var(--red);
  padding: 0.75rem 1rem;
  overflow-x: auto;
  margin: 0 0 1rem;
}

code {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.8rem;
}

footer {
  border-top: 1px solid var(--rule);
  padding-top: 1rem;
  font-size: 0.85rem;
  color: #444;
}

@media (max-width: 40rem) {
  html { font-size: 100%; }
  h1 { font-size: 2.6rem; }
  header { padding-top: 2.5rem; }
}