:root { color-scheme: light; --ink: #1b2420; --muted: #5a6760; --paper: #fbfaf5; --accent: #146c5b; --line: #d9ded8; --warm: #f0ead8; }
* { box-sizing: border-box; }
body { margin: 0; background: var(--paper); color: var(--ink); font: 18px/1.58 Georgia, "Times New Roman", serif; }
main { max-width: 760px; margin: 0 auto; padding: 3.5rem 1.5rem 5rem; }
h1, h2 { font-family: ui-sans-serif, system-ui, sans-serif; line-height: 1.13; }
h1 { font-size: clamp(2rem, 6vw, 3.5rem); margin: 0 0 .4rem; letter-spacing: -.04em; }
h2 { font-size: 1.25rem; margin: 2.5rem 0 .5rem; }
.eyebrow, .meta { font: 600 .8rem/1.4 ui-sans-serif, system-ui, sans-serif; text-transform: uppercase; letter-spacing: .09em; color: var(--accent); }
.lede { font-size: 1.2rem; color: var(--muted); }
.diagram, .practice { padding: 1.25rem; border: 1px solid var(--line); border-radius: 8px; background: white; }
.diagram { font-family: ui-monospace, SFMono-Regular, monospace; white-space: pre-wrap; line-height: 1.4; }
.practice { background: var(--warm); }
button { border: 0; border-radius: 5px; background: var(--accent); color: white; padding: .6rem .9rem; font: 600 .9rem ui-sans-serif, system-ui, sans-serif; cursor: pointer; }
input { width: 100%; margin: .6rem 0; padding: .6rem; border: 1px solid #aab7af; border-radius: 5px; font: inherit; }
#feedback { min-height: 1.5em; font-family: ui-sans-serif, system-ui, sans-serif; font-size: .92rem; }
a { color: var(--accent); }
footer { margin-top: 3rem; padding-top: 1rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .9rem; }


/* ---- generated navigation ---- */
.breadcrumbs { font: 600 .78rem/1.4 ui-sans-serif, system-ui, sans-serif;
  text-transform: uppercase; letter-spacing: .09em; margin-bottom: 1.6rem; }
.breadcrumbs a { text-decoration: none; }
.breadcrumbs .sep { color: var(--muted); margin: 0 .45rem; }
.grid { display: grid; gap: 1rem; margin: 1.5rem 0 0;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); }
.card { display: block; padding: 1.05rem 1.15rem; border: 1px solid var(--line);
  border-radius: 8px; background: #fff; text-decoration: none; color: inherit;
  transition: border-color .15s ease, transform .15s ease; }
.card:hover { border-color: var(--accent); transform: translateY(-1px); }
.card .kind { font: 600 .7rem/1.4 ui-sans-serif, system-ui, sans-serif;
  text-transform: uppercase; letter-spacing: .1em; color: var(--accent); }
.card h3 { font-family: ui-sans-serif, system-ui, sans-serif; font-size: 1.05rem;
  margin: .35rem 0 0; line-height: 1.25; letter-spacing: -.01em; }
.card .desc { margin: .4rem 0 0; color: var(--muted); font-size: .9rem; }
.count { color: var(--muted); font-size: .9rem; }