:root {
  --course-bg: #efe6d7;
  --course-paper: #fffaf0;
  --course-ink: #241f1a;
  --course-muted: #665b4d;
  --course-sepia: #7b3f2a;
  --course-green: #2f5d50;
  --course-line: #d8cdbb;
  --course-shadow: 0 10px 28px rgba(42, 33, 24, .14);
}
body { scroll-padding-top: 92px; }
.course-shell {
  position: sticky;
  top: 0;
  z-index: 50;
  background: linear-gradient(180deg, rgba(255,250,240,.98), rgba(239,230,215,.94));
  border-bottom: 1px solid var(--course-line);
  box-shadow: 0 4px 18px rgba(48, 37, 26, .10);
  backdrop-filter: blur(10px);
}
.course-shell-inner {
  max-width: 1120px;
  margin: 0 auto;
  padding: 10px 18px;
  display: grid;
  grid-template-columns: minmax(180px, 1fr) auto;
  gap: 14px;
  align-items: center;
}
.course-brand { min-width: 0; }
.course-brand strong { display: block; color: var(--course-ink); font-size: 1rem; line-height: 1.2; }
.course-brand span { color: var(--course-muted); font-size: .88rem; }
.course-actions { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 8px; }
.course-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  min-height: 34px;
  padding: 7px 11px;
  border: 1px solid var(--course-line);
  border-radius: 999px;
  background: #f7efe1;
  color: #302820;
  text-decoration: none;
  font: 700 .9rem system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  cursor: pointer;
}
.course-btn.primary { background: var(--course-sepia); color: #fff; border-color: var(--course-sepia); }
.course-btn:hover { filter: brightness(.97); }
.course-btn[aria-disabled="true"] { opacity: .48; pointer-events: none; }
.course-meter { grid-column: 1 / -1; display: grid; grid-template-columns: minmax(160px, 1fr) auto; gap: 10px; align-items: center; }
.course-meter-track { height: 10px; border-radius: 999px; overflow: hidden; background: #dfd0ba; }
.course-meter-fill { display: block; width: 0; height: 100%; background: linear-gradient(90deg, var(--course-green), var(--course-sepia)); transition: width .25s ease; }
.course-meter-text { font-size: .86rem; color: var(--course-muted); white-space: nowrap; }
.course-chapter-nav {
  max-width: 1120px;
  margin: 16px auto 0;
  padding: 0 18px;
  display: flex;
  justify-content: space-between;
  gap: 10px;
}
.course-chapter-nav.bottom { margin: 26px auto 34px; }
.course-status-row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; margin: 12px 0 4px; }
.course-status-pill { border: 1px solid var(--course-line); background: #f7efe1; color: var(--course-muted); border-radius: 999px; padding: 6px 10px; font-size: .9rem; }
.course-index-page {
  min-height: 100vh;
  margin: 0;
  background: linear-gradient(180deg, #e9dcc8 0%, #f6efe4 48%, #e7dccb 100%);
  color: var(--course-ink);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
.course-dashboard { max-width: 1160px; margin: 0 auto; padding: 24px 18px 54px; }
.course-hero {
  min-height: 360px;
  border-radius: 20px;
  overflow: hidden;
  display: grid;
  align-items: end;
  background: linear-gradient(180deg, rgba(26,20,15,.12), rgba(26,20,15,.68)), url('Nat-Kapitel-01.jpg') center/cover no-repeat;
  box-shadow: var(--course-shadow);
}
.course-hero-text { padding: clamp(24px, 5vw, 54px); color: #fffaf0; max-width: 760px; }
.course-hero-text h1 { margin: 0 0 10px; font-size: clamp(2.4rem, 7vw, 5rem); line-height: .98; letter-spacing: 0; }
.course-hero-text p { margin: 0; font-size: clamp(1rem, 2vw, 1.25rem); color: #f4eadb; }
.dashboard-grid { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(280px, .75fr); gap: 18px; margin-top: 20px; }
.dashboard-panel, .chapter-list, .certificate-panel {
  background: rgba(255,250,240,.94);
  border: 1px solid var(--course-line);
  border-radius: 18px;
  box-shadow: var(--course-shadow);
  padding: 20px;
}
.dashboard-stats { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; }
.stat { background: #f6eddf; border: 1px solid var(--course-line); border-radius: 14px; padding: 14px; }
.stat strong { display: block; font-size: 1.8rem; color: var(--course-sepia); line-height: 1; }
.stat span { color: var(--course-muted); font-size: .92rem; }
.chapter-list { margin-top: 18px; }
.chapter-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 12px; }
.chapter-card {
  display: grid;
  grid-template-columns: 74px 1fr;
  min-height: 92px;
  overflow: hidden;
  border: 1px solid var(--course-line);
  border-radius: 12px;
  background: #fffdf7;
  text-decoration: none;
  color: var(--course-ink);
}
.chapter-thumb { background-size: cover; background-position: center; }
.chapter-copy { padding: 10px 12px; min-width: 0; }
.chapter-copy strong { display: block; font-size: .95rem; line-height: 1.25; }
.chapter-copy span { display: block; color: var(--course-muted); font-size: .85rem; margin-top: 4px; }
.chapter-state { margin-top: 8px; font-weight: 800; color: var(--course-green); }
.certificate { border: 2px solid #b99a6e; padding: 22px; background: #fffaf0; text-align: center; }
.certificate h2 { font-family: Georgia, "Times New Roman", serif; font-size: 2rem; margin: 0 0 8px; color: var(--course-sepia); }
.certificate input { width: 100%; max-width: 360px; padding: 9px 10px; border: 1px solid var(--course-line); border-radius: 10px; background: #fffdf7; }
@media (max-width: 760px) {
  .course-shell-inner { grid-template-columns: 1fr; }
  .course-actions { justify-content: flex-start; }
  .course-meter { grid-template-columns: 1fr; }
  .dashboard-grid, .dashboard-stats { grid-template-columns: 1fr; }
  .course-chapter-nav { flex-direction: column; }
}
@media print {
  body * { visibility: hidden !important; }
  #certificate, #certificate * { visibility: visible !important; }
  #certificate { position: absolute; inset: 20px; box-shadow: none; }
  .no-print { display: none !important; }
}