/* Set like the app: white on black or black on white, IBM Plex Mono for
   labels, Courier New for prose. The fonts are served from this site, not
   a font service, so a visit makes no request anywhere else. */

@font-face {
  font-family: "IBM Plex Mono";
  src: url("fonts/IBMPlexMono-Regular.ttf") format("truetype");
  font-weight: 400;
  font-display: swap;
}
@font-face {
  font-family: "IBM Plex Mono";
  src: url("fonts/IBMPlexMono-Medium.ttf") format("truetype");
  font-weight: 500;
  font-display: swap;
}

:root {
  --surface: #ffffff;
  --ink: #000000;
  --ink-secondary: #545454;
  --rule: #a8a8a8;
}
@media (prefers-color-scheme: dark) {
  :root {
    --surface: #000000;
    --ink: #ffffff;
    --ink-secondary: #b4b4b4;
    --rule: #5a5a5a;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--surface);
  color: var(--ink);
  font: 16px/1.6 "Courier New", Courier, monospace;
}

main {
  max-width: 36rem;
  margin: 0 auto;
  padding: 3rem 20px 4rem;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.label, header a, nav a, h2 {
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-weight: 500;
  font-size: 12px;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

header a { color: var(--ink); text-decoration: none; }

h1 {
  font-size: 1.5rem;
  font-weight: bold;
  line-height: 1.3;
  margin: 0 0 1.5rem;
}

h2 {
  margin: 2.5rem 0 0.75rem;
  color: var(--ink);
}

p, ul { margin: 0 0 1rem; }
ul { padding-left: 1.25rem; }

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

.secondary { color: var(--ink-secondary); }

/* Dates and legal references under a page title. */
.note { color: var(--ink-secondary); font-style: italic; }

footer {
  margin-top: 3rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--rule);
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
}

nav a { color: var(--ink-secondary); text-decoration: none; }
nav a:hover, nav a[aria-current="page"] { color: var(--ink); }