:root {
  --page: #FFFFFF;
  --ink: #000000;
  --board: #1F4A3C;
  --chalk: #F1EDE0;
  --yellow: #E8C547;
  --sage: #9DB8A8;
  --rule: #C9CFCB;
  --muted: #4F5A55;
  --serif: "IBM Plex Serif", "Charter", Georgia, serif;
  --sans: "IBM Plex Sans", "Helvetica Neue", Arial, sans-serif;
  --mono: "IBM Plex Mono", Menlo, Consolas, monospace;
}

html { background: var(--page); }
body {
  margin: 0;
  color: var(--ink);
  font: 17px/1.65 var(--serif);
  -webkit-text-size-adjust: 100%;
}
main { max-width: 41rem; margin: 0 auto; padding: 2.5rem 1.25rem 5rem; }

header { border-bottom: 2px solid var(--board); padding-bottom: 1.25rem; margin-bottom: 2rem; }
.site { font-family: var(--sans); font-size: .95rem; margin: 0 0 1rem; }
.site a { text-decoration: none; }
h1, h2, h3 { font-family: var(--sans); color: var(--board); line-height: 1.2; margin: 0; }
h1 { font-size: 2.1rem; font-weight: 600; letter-spacing: -.01em; }
.byline { font-family: var(--sans); font-size: .95rem; color: var(--muted); margin: .5rem 0 0; }
h2 { font-size: 1.45rem; font-weight: 600; margin: 2.75rem 0 .9rem; }
h3 { font-size: 1.1rem; font-weight: 600; margin: 2rem 0 .6rem; }

p { margin: 0 0 1.1rem; }
a { color: var(--board); text-decoration: underline; text-underline-offset: 3px; }
a:focus-visible { outline: 3px solid var(--yellow); outline-offset: 2px; }

ol.chapters { padding-left: 1.4rem; margin: 1rem 0 0; }
ol.chapters li { margin-bottom: .75rem; }
ol.chapters b { font-family: var(--sans); font-weight: 600; }
ol.chapters b a { text-decoration: none; }
ol.chapters span { display: block; font-family: var(--sans); font-size: .92rem; color: var(--muted); }
ol.chapters span.soon { font-style: italic; }
.repo { font-family: var(--sans); font-size: .92rem; margin-top: 2rem; }

.code, pre {
  background: var(--board);
  color: var(--chalk);
  font: 14px/1.55 var(--mono);
  padding: 1.1rem 1.25rem;
  margin: 1.25rem 0;
  overflow-x: auto;
  tab-size: 4;
}
.code pre { background: none; padding: 0; margin: 0; }
.code .c, .code .c1, .code .cm { color: var(--sage); }
.code .s, .code .s1, .code .s2, .code .sa { color: var(--yellow); }
code { font-family: var(--mono); font-size: .92em; }
p code, li code { color: var(--board); }

table { border-collapse: collapse; margin: 1rem 0 1.5rem; font-size: .95rem; }
th, td { padding: .35rem .9rem .35rem 0; text-align: left; border-bottom: 1px solid var(--rule); }
th { font-family: var(--sans); font-weight: 600; border-bottom: 2px solid var(--board); }
td[align="right"], th[align="right"] { text-align: right; font-variant-numeric: tabular-nums; }

img { display: block; max-width: 100%; height: auto; margin: 1.75rem auto .6rem; }
img + p, p:has(> img) + p { font-family: var(--sans); font-size: .9rem; color: var(--muted); }

ol, ul { padding-left: 1.4rem; }
li { margin-bottom: .6rem; }

nav.pager { font-family: var(--sans); font-size: .92rem; margin-top: 3.5rem; border-top: 1px solid var(--rule); padding-top: 1rem; }
nav.pager a { display: inline-block; margin-right: 1.5rem; }

@media (max-width: 480px) {
  body { font-size: 16px; }
  h1 { font-size: 1.7rem; }
  main { padding-top: 1.75rem; }
}
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}
.signature { font-family: var(--sans); font-style: italic; color: var(--muted); }