:root{
  font-family:Inter,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;
  color:#161719;background:#f6f7f8;
  --ink:#161719;--muted:#676d74;--line:#e5e8eb;--paper:#fff;--soft:#f2f4f5;
  --accent:#111214;--good:#eef8f1;--warn:#fff7df;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:linear-gradient(180deg,#fff 0,#f6f7f8 100%);line-height:1.78}
a{color:inherit}
.learn-shell{width:min(calc(100% - 28px),780px);margin:0 auto;padding:22px 0 72px}
.learn-topbar{display:flex;align-items:center;justify-content:space-between;gap:14px;margin-bottom:22px}
.learn-brand{font-weight:950;letter-spacing:-.03em;text-decoration:none;font-size:18px}
.learn-brand span{font-size:10px;color:#868b91;margin-left:4px;vertical-align:top}
.learn-back{font-size:13px;color:#5f656b;text-decoration:none;padding:8px 10px;border-radius:999px;background:#fff;border:1px solid var(--line)}
.breadcrumbs{font-size:12px;color:#858a90;margin:0 0 20px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.breadcrumbs a{text-decoration:none}
.eyebrow{margin:0 0 8px;font-size:11px;font-weight:900;letter-spacing:.14em;color:#767c83}
h1{font-size:clamp(29px,7.4vw,46px);line-height:1.18;letter-spacing:-.042em;margin:0 0 14px}
.lead{font-size:16px;color:#5e646a;margin:0 0 22px}
.keyword-note{font-size:11px;color:#90959a;margin-top:-10px;margin-bottom:20px}
.learn-card,.article-section,.quick-check,.related-card{background:var(--paper);border:1px solid var(--line);border-radius:22px;padding:22px;margin-top:16px;box-shadow:0 14px 34px rgba(17,18,20,.035)}
.learn-card h2,.article-section h2,.quick-check h2,.related-card h2{font-size:20px;line-height:1.35;margin:0 0 12px;letter-spacing:-.02em}
.learn-card p,.article-section p{margin:0 0 12px}
.learn-card p:last-child,.article-section p:last-child{margin-bottom:0}
.takeaway{background:#111214;color:#fff;border-color:#111214}
.takeaway h2{color:#fff}
.takeaway ul{margin:0;padding:0;list-style:none;display:grid;gap:9px}
.takeaway li{padding:10px 12px;border-radius:13px;background:rgba(255,255,255,.085);font-weight:800;line-height:1.55}
.article-section ul{padding-left:1.25em;margin:8px 0}
.article-section pre{white-space:pre-wrap;overflow-wrap:anywhere;background:#f4f6f7;border:1px solid #e9ebed;border-radius:15px;padding:14px;font-family:inherit;font-weight:750;line-height:1.65;margin:12px 0;color:#25282b}
.article-section code{font-family:ui-monospace,SFMono-Regular,Consolas,monospace;background:#f2f4f5;padding:.12em .35em;border-radius:6px}
.article-section blockquote{margin:12px 0;border-left:4px solid #202326;padding:4px 0 4px 14px;color:#4e545a}
.quick-check .question{padding:14px 0;border-top:1px solid #edf0f2}
.quick-check .question:first-of-type{border-top:0;padding-top:0}
.quick-check strong{display:block;margin-bottom:8px}
details{background:#f5f6f7;border:1px solid #e7eaec;border-radius:13px;padding:0 13px}
details+details{margin-top:8px}
summary{cursor:pointer;padding:11px 0;font-weight:850;list-style:none}
summary::-webkit-details-marker{display:none}
details[open]{padding-bottom:11px}
.answer{color:#33383d;font-weight:750}
.learn-cta{margin-top:20px;padding:22px;border-radius:22px;background:#111214;color:#fff}
.learn-cta small{display:block;color:#aeb4ba;font-size:11px;font-weight:800;letter-spacing:.08em;margin-bottom:5px}
.learn-cta h2{margin:0 0 7px;font-size:21px}
.learn-cta p{margin:0 0 14px;color:#d8dcdf}
.learn-cta a{display:block;text-align:center;padding:14px 16px;border-radius:14px;background:#fff;color:#111214;text-decoration:none;font-weight:950}
.related-list{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px}
.related-link{display:block;padding:13px 14px;border:1px solid var(--line);border-radius:14px;text-decoration:none;font-weight:800;background:#fafbfb;line-height:1.45}
.learn-footer{font-size:12px;color:#858a90;margin:20px 4px 0}
.topic-groups{display:grid;gap:18px;margin-top:20px}
.topic-group h2{font-size:17px;margin:0 0 9px}
.topic-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:9px}
.topic-link{display:block;padding:15px;border-radius:16px;background:#fff;border:1px solid var(--line);text-decoration:none;font-weight:850;font-size:14px;line-height:1.5}
.topic-link small{display:block;color:#8b9096;font-size:11px;font-weight:650;margin-top:4px}
.status-pill{display:inline-flex;align-items:center;gap:5px;font-size:10px;font-weight:900;color:#53605a;background:#eef7f0;border-radius:999px;padding:4px 8px;margin-bottom:10px}
@media(max-width:560px){
  .learn-shell{padding-top:15px;padding-bottom:54px}
  .learn-topbar{margin-bottom:18px}
  .learn-card,.article-section,.quick-check,.related-card,.learn-cta{padding:17px;border-radius:18px}
  .related-list,.topic-grid{grid-template-columns:1fr}
  h1{font-size:31px}
  .lead{font-size:15px}
}

.scope-badge{display:inline-flex;align-items:center;font-size:11px;font-weight:900;padding:6px 10px;border-radius:999px;background:#fff1d6;color:#7a4a00;border:1px solid #f0d79e;margin:0 0 12px}.scope-badge.future{background:#e9f2ff;color:#18528b;border-color:#cfe0f7}.scope-note{margin:0 0 20px;padding:14px 16px;border:1px solid #f0d79e;background:#fff9eb;border-radius:16px;font-size:13px;color:#5d4a25;line-height:1.65}.scope-note a{font-weight:900}.future-topic{border-style:dashed}.revision-note{font-size:12px;color:#6c7278;background:#f3f5f6;border-radius:12px;padding:10px 12px;margin:14px 0}

.mini-scope{font-size:9px;padding:2px 5px;border-radius:999px;background:#fff1d6;color:#7a4a00;margin-left:5px;vertical-align:1px}

.learn-scope-switch {
  display: grid;
  gap: 10px;
  margin: 18px 0;
  padding: 14px;
  border: 1px solid #e5e7eb;
  border-radius: 16px;
  background: #fff;
}
.learn-scope-switch div { display: grid; gap: 3px; }
.learn-scope-switch small { font-weight: 800; letter-spacing: .1em; color: #6b7280; }
.learn-scope-switch strong { font-size: 16px; }
.learn-scope-switch span { font-size: 12px; color: #6b7280; }
.learn-scope-switch select {
  min-height: 44px; padding: 0 12px; border: 1px solid #d1d5db; border-radius: 12px; background: #fff; font: inherit;
}
.topic-scope-badge {
  display: inline-block; margin-left: 6px; padding: 2px 6px; border-radius: 999px;
  font-size: 10px; font-style: normal; background: #f3f4f6; color: #4b5563;
}
.topic-scope-badge.future { background: #eef2ff; color: #4338ca; }


/* v1.2: game overlay embed mode (class is injected by parent app) */
body.embedded-learning {
  background: #fff;
}

body.embedded-learning .learn-shell {
  width: min(calc(100% - 24px), 760px);
  padding-top: 16px;
  padding-bottom: 52px;
}

body.embedded-learning .learn-topbar,
body.embedded-learning .breadcrumbs,
body.embedded-learning .learn-scope-switch {
  display: none !important;
}

@media (max-width: 560px) {
  body.embedded-learning .learn-shell {
    width: min(calc(100% - 22px), 760px);
    padding-top: 14px;
    padding-bottom: calc(36px + env(safe-area-inset-bottom));
  }

  body.embedded-learning h1 {
    font-size: 28px;
  }

  body.embedded-learning .learn-card,
  body.embedded-learning .article-section,
  body.embedded-learning .quick-check,
  body.embedded-learning .related-card,
  body.embedded-learning .learn-cta {
    border-radius: 17px;
    padding: 16px;
  }
}