@font-face {
  font-family: "Aktua Plot";
  src: url("fonts/dejavu-sans-mono-plot.woff2") format("woff2");
  font-display: swap;
}

:root {
  --paper:          #eef3ea;
  --sheet:          #f8faf6;
  --grid:           #d3e2cc;
  --graphite:       #2a2f2b;
  --graphite-light: #5b655d;
  --ink:            #1f4fa0;

  --font-text: "Atkinson Hyperlegible Next", system-ui, sans-serif;
  --font-code: "Atkinson Hyperlegible Mono", ui-monospace, Menlo, Consolas, monospace;
  --font-plot: "Aktua Plot", ui-monospace, monospace;

  --measure: 42rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper:          #171d19;
    --sheet:          #1d2520;
    --grid:           #26332b;
    --graphite:       #dde5de;
    --graphite-light: #98a69b;
    --ink:            #8fb3f5;
  }
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-size: 106.25%;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  padding: 4rem 1rem 3rem;
  background: var(--paper);
  color: var(--graphite);
  font-family: var(--font-text);
  line-height: 1.55;
}

header,
main,
footer {
  max-width: var(--measure);
  margin: 0 auto;
}

a {
  color: var(--ink);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.2em;
}

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

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

h1 {
  margin: 0 0 0.75rem;
  font-size: 3rem;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
}

h2 {
  margin: 0 0 0.5rem;
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.3;
}

p,
ul {
  margin: 0 0 1rem;
}

ul {
  padding-left: 1.25rem;
}

li + li {
  margin-top: 0.25rem;
}

.lede {
  font-size: 1.15rem;
  max-width: 36rem;
}

code {
  font-family: var(--font-code);
  font-size: 0.9em;
}

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

main > section {
  margin-top: 3.5rem;
}

footer {
  margin-top: 4rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--grid);
  color: var(--graphite-light);
  font-size: 0.9rem;
}

pre {
  margin: 0 0 1.25rem;
  padding: 1rem 1.25rem;
  overflow-x: auto;
  font-size: 0.85rem;
  line-height: 1.5;
}

pre code,
pre samp {
  font-size: inherit;
}

pre.code {
  background: var(--sheet);
  border: 1px solid var(--grid);
}

pre.output {
  font-family: var(--font-plot);
  line-height: 1.15;
  background-color: var(--paper);
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 1.25rem 1.25rem;
  border: 1px solid var(--grid);
}

pre.output samp {
  font-family: inherit;
}

@media (max-width: 36rem) {
  body {
    padding-top: 2.5rem;
  }

  h1 {
    font-size: 2.5rem;
  }

  pre {
    margin-left: -1rem;
    margin-right: -1rem;
    border-left: 0;
    border-right: 0;
  }
}