:root {
  --ink: #1c1915;
  --muted: #5c564c;
  --paper: #f3efe6;
  --card: #fffdf8;
  --line: #e2d9c8;
  --green: #0f6e56;
  --green-soft: #e5f4ef;
  --copper: #9a3412;
  --copper-soft: #fde8dc;
  --blue: #1e3a5f;
  --term: #14202b;
  --term-ink: #e7eef4;
  --term-dim: #93a4b3;
  --term-ok: #7dcea0;
  --shadow: 0 12px 32px rgba(40, 28, 12, 0.08);
  color-scheme: light;
  font-family: "Iowan Old Style", Palatino, "Palatino Linotype", Georgia, serif;
}

* { box-sizing: border-box; }
html, body { margin: 0; height: 100%; background: var(--paper); color: var(--ink); }
body { display: flex; flex-direction: column; overflow: hidden; }
button, input { font: inherit; }
button { cursor: pointer; }
code, .mono, .term-out, .term-in { font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace; }

.top {
  display: flex;
  align-items: end;
  gap: 20px;
  padding: 18px 22px 14px;
  border-bottom: 1px solid var(--line);
  background: rgba(243, 239, 230, 0.94);
  position: sticky;
  top: 0;
  z-index: 2;
}
.brand h1 { margin: 0; font-size: 1.45rem; font-weight: 600; letter-spacing: -0.02em; }
.eyebrow { margin: 0 0 2px; color: var(--muted); font-size: 0.78rem; letter-spacing: 0.04em; text-transform: uppercase; }
.search { display: flex; flex-direction: column; gap: 4px; min-width: 240px; color: var(--muted); font-size: 0.78rem; }
.search input {
  border: 1px solid var(--line);
  background: var(--card);
  border-radius: 8px;
  padding: 8px 10px;
  color: var(--ink);
}
.meter { margin: 0 0 8px auto; color: var(--muted); }
.ghost, .solid, .quiet {
  border-radius: 8px;
  padding: 8px 12px;
}
.ghost { background: transparent; border: 1px solid var(--line); color: var(--ink); }
.solid { background: var(--green); color: white; border: 0; }
.quiet { background: transparent; border: 0; color: var(--blue); padding-left: 0; }

.shell { display: grid; grid-template-columns: 280px 1fr; flex: 1; min-height: 0; }
.rail, #stage { overflow: auto; min-height: 0; }
.rail { border-right: 1px solid var(--line); padding: 12px; }
.rail button.nav {
  display: block;
  width: 100%;
  text-align: left;
  background: transparent;
  border: 0;
  border-radius: 8px;
  padding: 8px 10px;
  color: var(--ink);
}
.rail button.nav[aria-current="page"], .rail button.lesson.active { background: var(--card); box-shadow: var(--shadow); }
.track-name { display: flex; justify-content: space-between; gap: 8px; font-weight: 600; }
.track-count { color: var(--muted); font-weight: 400; font-size: 0.85rem; }
.lesson {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  width: calc(100% - 8px);
  margin-left: 8px;
  text-align: left;
  background: transparent;
  border: 0;
  border-radius: 8px;
  padding: 6px 8px;
  color: var(--muted);
}
.lesson .mark { width: 1.1rem; color: var(--green); }
.stage { padding: 28px 34px 80px; max-width: 920px; }
.stage h2 { margin: 0 0 8px; font-size: 2rem; letter-spacing: -0.03em; }
.lede { font-size: 1.15rem; color: var(--muted); }
.path { display: grid; gap: 10px; margin-top: 22px; }
.station {
  display: grid;
  grid-template-columns: 52px 1fr auto;
  gap: 12px;
  align-items: center;
  width: 100%;
  text-align: left;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px 14px;
  box-shadow: var(--shadow);
  color: inherit;
}
.ord {
  width: 40px; height: 40px; border-radius: 50%;
  display: grid; place-items: center;
  background: var(--green-soft); color: var(--green); font-weight: 700;
}
.station small { color: var(--muted); }
.pill { font-size: 0.78rem; color: var(--muted); }
.block h3 { margin: 22px 0 8px; font-size: 1.15rem; }
.block p, .block li { line-height: 1.55; }
.block ul { margin: 8px 0; padding-left: 1.2rem; }
pre {
  background: var(--term);
  color: var(--term-ink);
  padding: 12px 14px;
  border-radius: 10px;
  overflow: auto;
}
.callout {
  border-left: 3px solid var(--blue);
  background: #eef3f8;
  padding: 10px 12px;
  border-radius: 0 10px 10px 0;
}
.callout.caution { border-color: var(--copper); background: var(--copper-soft); }
.objectives { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 12px 16px; }
.lab, .quiz, .term {
  margin-top: 22px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 14px 16px;
}
.term { background: var(--term); color: var(--term-ink); }
.term-log { min-height: 140px; white-space: pre-wrap; margin: 0 0 10px; }
.term form { display: flex; gap: 8px; }
.term input {
  flex: 1;
  background: transparent;
  border: 0;
  border-bottom: 1px solid #345066;
  color: var(--term-ink);
  padding: 6px 0;
}
.prompt { color: var(--term-ok); }
.ok { color: var(--term-ok); }
.dim { color: var(--term-dim); }
.choices { display: grid; gap: 8px; margin: 12px 0; }
.choices label {
  display: flex; gap: 8px; align-items: flex-start;
  border: 1px solid var(--line); border-radius: 8px; padding: 8px 10px;
}
.choices label.right { background: var(--green-soft); border-color: var(--green); }
.choices label.wrong { background: var(--copper-soft); border-color: var(--copper); }
.why { color: var(--muted); margin: 4px 0 0 1.4rem; }
.row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
.pass { color: var(--green); font-weight: 700; }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 10px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 12px; }
.card h3 { margin: 0 0 6px; font-size: 1rem; }
.card a { color: var(--blue); text-decoration: none; }
.card a:hover { text-decoration: underline; }
.mono { font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace; font-size: 0.85rem; }
.check { display: flex; gap: 10px; align-items: flex-start; margin: 10px 0; line-height: 1.45; }
.hidden { display: none; }

@media (max-width: 720px) {
  .top { flex-wrap: wrap; align-items: stretch; }
  .meter { margin-left: 0; }
  .shell { grid-template-columns: 1fr; grid-template-rows: 34vh 1fr; }
  .rail { border-right: 0; border-bottom: 1px solid var(--line); }
  .stage { padding: 20px 16px 64px; }
}