:root {
  color-scheme: light;
  --paper: #fbfaf6;
  --ink: #1f2b2b;
  --muted: #485958;
  --accent: #185c54;
  --accent-light: #e5f1ed;
  --line: #d4dfd8;
  font-family: "Source Sans 3", system-ui, sans-serif;
  line-height: 1.55;
  color: var(--ink);
  background: var(--paper);
}

* { box-sizing: border-box; }
body { margin: 0; }
a { color: var(--accent); text-underline-offset: .2em; }
a:hover { text-decoration-thickness: .13em; }
:focus-visible { outline: 3px solid #a44a21; outline-offset: 4px; }
h1, h2, h3, h4, p, ul { margin-top: 0; }
h1, h2, h3 { line-height: 1.13; }
h1, h2 { font-family: "Source Serif 4", Georgia, serif; }
h2 { font-size: clamp(1.65rem, 4vw, 2.1rem); }
h3 { font-size: clamp(1.15rem, 2.5vw, 1.35rem); margin-bottom: .4rem; }
h3 a { color: var(--ink); text-decoration: none; }
h3 a:hover { text-decoration: underline; }
h4 { font-size: .98rem; margin-bottom: .28rem; }
.wrap { width: min(100% - 3rem, 63rem); margin: 0 auto; }
.skip { position: absolute; top: 1rem; left: 1rem; transform: translateY(-200%); }
.skip:focus { transform: none; background: var(--paper); padding: .5rem; }
.hero { background: var(--accent-light); border-bottom: 1px solid var(--line); padding: 3rem 0 2.7rem; }
.section-label { font-weight: 700; color: var(--accent); margin-bottom: .65rem; }
h1 { font-size: clamp(2.65rem, 7vw, 4.95rem); margin: 0 0 .45rem; letter-spacing: -.035em; }
.subtitle { font-size: clamp(1.1rem, 4vw, 1.65rem); margin-bottom: .6rem; }
.authors, .note, .chapter p { color: var(--muted); }
.authors { margin-bottom: 1.4rem; }
.intro { max-width: 48rem; }
.actions { display: flex; align-items: center; flex-wrap: wrap; gap: .8rem 1.4rem; }
.button { background: var(--accent); color: white; padding: .65rem .95rem; font-weight: 650; border-radius: .4rem; text-decoration: none; }
.button:hover { background: #124740; }
nav { padding: 1.25rem 0; border-bottom: 1px solid var(--line); }
nav ul { display: flex; gap: .55rem 1.55rem; flex-wrap: wrap; padding: 0; margin: 0; list-style: none; }
nav a { display: block; padding: .2rem 0; }
.note { margin: 1.15rem 0 2.2rem; max-width: 57rem; }
section + section { margin-top: 2.65rem; }
section > h2 { padding-bottom: .85rem; border-bottom: 2px solid var(--accent); margin-bottom: 0; }
.chapter { padding: 1.1rem 0; display: grid; grid-template-columns: 2.5rem minmax(0, 1fr); gap: .7rem; border-bottom: 1px solid var(--line); }
.chapter:target { background: var(--accent-light); }
.number { color: var(--accent); font-variant-numeric: tabular-nums; font-size: 1.15rem; font-weight: 700; }
.downloads { display: grid; grid-template-columns: minmax(0, 3fr) minmax(0, 2fr); gap: .3rem 1.25rem; }
.downloads ul { margin: 0 0 .65rem; padding: 0; list-style: none; }
.downloads a { display: inline-block; overflow-wrap: anywhere; padding: .13rem 0; }
summary { color: var(--accent); cursor: pointer; width: fit-content; }
details + details { margin-top: .35rem; }
pre { padding: .65rem .8rem; margin: .45rem 0 0; background: #edf2ef; border: 1px solid var(--line); white-space: pre-wrap; overflow-wrap: anywhere; }
.chapter details:first-of-type pre { max-height: 24rem; overflow: auto; }
code { font-family: "IBM Plex Mono", ui-monospace, monospace; font-size: .88em; }
.workshop { background: var(--accent-light); border-radius: .45rem; padding: 1.35rem 1.6rem; margin-top: 2.6rem; }
.workshop h2 { margin-bottom: .5rem; }
.workshop p { margin-bottom: .6rem; }
footer { padding: 1.4rem 0 2rem; }

@media (max-width: 42rem) {
  .wrap { width: calc(100% - 2rem); }
  .hero { padding: 2rem 0; }
  .chapter { grid-template-columns: 1.7rem minmax(0, 1fr); gap: .4rem; }
  .downloads { grid-template-columns: minmax(0, 1fr); }
  .workshop { padding: 1.15rem; }
}