:root {
  --good: #1f7a52;
  --good-soft: #e3f3ea;
  --warn: #9a6514;
  --warn-soft: #fbefd9;
  --bad: #a8402a;
  --bad-soft: #fbe7e2;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --good: #6fd3a3;
    --good-soft: #17302a;
    --warn: #e9b25c;
    --warn-soft: #33281a;
    --bad: #f08f78;
    --bad-soft: #3a211c;
  }
}

.learn { padding-top: 40px; padding-bottom: 72px; min-height: 70vh; }
.learn h1 { font-size: clamp(1.9rem, 4.4vw, 2.8rem); }
.crumb { display: inline-block; margin-bottom: 18px; font-size: .92rem; text-decoration: none; color: var(--muted); }
.crumb:hover { color: var(--accent); }

/* start card */
.start { background: var(--accent-soft); border-radius: var(--radius); padding: 28px; margin: 24px 0 40px; display: flex; gap: 24px; align-items: center; justify-content: space-between; flex-wrap: wrap; }
.start h2 { font-size: 1.5rem; margin-bottom: .3em; }
.start p { margin: 0; color: var(--muted); max-width: 560px; }
.start .actions { display: flex; flex-direction: column; align-items: flex-start; gap: 8px; }

/* skill map */
.group { margin-top: 32px; }
.group h2 { font-size: 1.25rem; margin-bottom: 12px; }
.skills { display: grid; gap: 10px; grid-template-columns: repeat(2, minmax(0, 1fr)); }
@media (max-width: 720px) { .skills { grid-template-columns: minmax(0, 1fr); } }
.skill { display: flex; align-items: center; justify-content: space-between; gap: 12px; background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 14px 16px; text-decoration: none; color: var(--ink); transition: border-color .15s; }
.skill:hover { border-color: var(--accent); }
.skill strong { display: block; font-weight: 600; }
.skill span.desc { display: block; font-size: .88rem; color: var(--muted); }
.status { flex: none; font-size: .75rem; font-weight: 600; padding: 3px 10px; border-radius: 999px; background: var(--band); color: var(--muted); border: 1px solid var(--line); white-space: nowrap; }
.status.mastered { background: var(--good-soft); color: var(--good); border-color: transparent; }
.status.known { background: var(--good-soft); color: var(--good); border-color: transparent; opacity: .8; }
.status.review { background: var(--warn-soft); color: var(--warn); border-color: transparent; }
.status.gap { background: var(--bad-soft); color: var(--bad); border-color: transparent; }

/* question card */
.qcard { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 28px; margin-top: 20px; max-width: 760px; }
.qmeta { display: flex; justify-content: space-between; align-items: center; gap: 12px; color: var(--muted); font-size: .9rem; margin-bottom: 14px; flex-wrap: wrap; }
.prompt { font-family: "Fraunces", Georgia, serif; font-size: clamp(1.35rem, 3.6vw, 1.9rem); line-height: 1.3; margin: 0 0 20px; overflow-wrap: anywhere; }
.answer-row { display: flex; gap: 10px; flex-wrap: wrap; }
.answer-row input { flex: 1 1 220px; min-width: 0; font: 500 1.2rem "Inter", sans-serif; padding: 12px 14px; border-radius: 10px; border: 2px solid var(--line); background: var(--bg); color: var(--ink); }
.answer-row input:focus { outline: none; border-color: var(--accent); }
button.btn { cursor: pointer; font: 600 1rem "Inter", sans-serif; }
button.btn:disabled { opacity: .5; cursor: default; transform: none; }
.keys { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px; }
.keys button { font: 500 1rem "Inter", sans-serif; min-width: 40px; padding: 6px 10px; border-radius: 8px; border: 1px solid var(--line); background: var(--band); color: var(--ink); cursor: pointer; }
.keys button:hover { border-color: var(--accent); }
.example { font-size: .85rem; color: var(--muted); margin-top: 8px; }
.linkbtn { background: none; border: 0; padding: 0; color: var(--accent); font: 500 .95rem "Inter", sans-serif; cursor: pointer; text-decoration: underline; }

/* feedback */
.feedback { margin-top: 18px; padding: 14px 16px; border-radius: 10px; font-weight: 500; }
.feedback.ok { background: var(--good-soft); color: var(--good); }
.feedback.bad { background: var(--bad-soft); color: var(--bad); }
.feedback.info { background: var(--warn-soft); color: var(--warn); }
.hints { margin: 16px 0 0; padding: 0; list-style: none; display: grid; gap: 8px; }
.hints li { background: var(--band); border-left: 4px solid var(--gold); border-radius: 0 10px 10px 0; padding: 10px 14px; }
.hints li b { color: var(--gold); margin-right: 6px; }
.next-row { display: flex; gap: 12px; align-items: center; margin-top: 18px; flex-wrap: wrap; }

/* streak dots */
.dots { display: inline-flex; gap: 6px; align-items: center; }
.dots i { width: 14px; height: 14px; border-radius: 50%; border: 2px solid var(--accent); display: inline-block; }
.dots i.on { background: var(--accent); }

/* lesson board */
.lesson-board { margin: 24px 0 8px; max-width: 760px; }
.lesson-board .board-row code { font-size: 1.2rem; }
.lesson-board .note { font-size: .88rem; opacity: .75; flex-basis: 100%; padding-left: 88px; }
@media (max-width: 480px) { .lesson-board .note { padding-left: 0; } }
.tipbox { max-width: 760px; background: var(--band); border-radius: 10px; padding: 14px 18px; margin-top: 18px; color: var(--muted); }
.tipbox strong { color: var(--ink); }
.prereq { margin-top: 18px; font-size: .95rem; color: var(--muted); }

/* results path */
.path { counter-reset: step; list-style: none; padding: 0; margin: 20px 0 0; display: grid; gap: 10px; max-width: 760px; }
.path li { counter-increment: step; }
.path li a { display: flex; align-items: center; gap: 14px; }
.path li a::before { content: counter(step); flex: none; display: inline-grid; place-items: center; width: 32px; height: 32px; border-radius: 50%; background: var(--accent-soft); color: var(--accent); font-weight: 700; }
.path li a > div { flex: 1; min-width: 0; }
details.known-list { margin-top: 28px; max-width: 760px; }
details.known-list summary { cursor: pointer; font-weight: 600; }
details.known-list ul { color: var(--muted); }
.lead-sm { color: var(--muted); max-width: 640px; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }