.skeleton {
  background: linear-gradient(90deg, rgba(0,0,0,0.06) 25%, rgba(0,0,0,0.10) 37%, rgba(0,0,0,0.06) 63%);
  background-size: 400% 100%;
  animation: skeleton-shimmer 1.4s ease infinite;
  border-radius: 0.375rem;
}
@keyframes skeleton-shimmer { 0% { background-position: 100% 50%; } 100% { background-position: 0 50%; } }
:focus-visible { outline: 2px solid #C17F3E; outline-offset: 2px; }
@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
}

/* ---- Nav tree (left column) ---- */
.nav-module > summary { cursor: pointer; font-weight: 600; padding: 0.5rem 0.25rem; list-style: none; }
.nav-module > summary::-webkit-details-marker { display: none; }
.nav-topic > summary { cursor: pointer; padding: 0.35rem 0.25rem 0.35rem 0.75rem; font-size: 0.8rem; color: #2A2A28; list-style: none; }
.nav-topic > summary::-webkit-details-marker { display: none; }
.nav-lesson-link {
  display: flex; align-items: center; gap: 0.5rem;
  padding: 0.35rem 0.5rem 0.35rem 1.5rem; font-size: 0.8rem; border-radius: 0.375rem;
  color: #2A2A28;
}
.nav-lesson-link:hover { background: rgba(193,127,62,0.08); }
.nav-lesson-link.is-current { background: rgba(193,127,62,0.15); font-weight: 600; color: #16302B; }
.nav-dot { width: 6px; height: 6px; border-radius: 9999px; background: #cbd0ce; flex-shrink: 0; }
.nav-dot.is-complete { background: #2F6F4F; }

/* ---- Progress bar ---- */
.progress-bar-track { height: 8px; border-radius: 9999px; background: rgba(42,42,40,0.08); overflow: hidden; }
.progress-bar-fill { height: 100%; background: #C17F3E; border-radius: 9999px; transition: width 0.4s ease; }

/* ---- Lesson content typography ---- */
.lesson-prose { line-height: 1.75; color: #2A2A28; }
.lesson-prose p { margin-bottom: 1rem; }
.lesson-prose h1, .lesson-prose h2, .lesson-prose h3 { font-family: 'Space Grotesk', sans-serif; font-weight: 600; color: #16302B; margin: 1.5rem 0 0.75rem; }
.lesson-prose ul { list-style: disc; margin: 0 0 1rem 1.5rem; }
.lesson-prose ol { list-style: decimal; margin: 0 0 1rem 1.5rem; }
.lesson-prose a { color: #B8702F; text-decoration: underline; }
.lesson-prose img { max-width: 100%; height: auto; border-radius: 0.5rem; }
.lesson-prose table { border-collapse: collapse; width: 100%; margin-bottom: 1rem; }
.lesson-prose th, .lesson-prose td { border: 1px solid #E5E0D5; padding: 0.4rem 0.6rem; text-align: left; }
.lesson-prose pre { font-family: ui-monospace, monospace; background: #F2EDE3; border-radius: 0.375rem; padding: 0.75rem; overflow-x: auto; margin-bottom: 1rem; }
.lesson-prose code { font-family: ui-monospace, monospace; background: #F2EDE3; border-radius: 0.375rem; padding: 0.1rem 0.3rem; }
.lesson-prose li { margin-bottom: 0.35rem; }

/* ---- Video / PDF embeds ---- */
.embed-16-9 { position: relative; width: 100%; padding-top: 56.25%; border-radius: 0.75rem; overflow: hidden; background: #16302B; }
.embed-16-9 iframe, .embed-16-9 video { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.pdf-embed { width: 100%; height: 70vh; border: 0; border-radius: 0.75rem; }

/* ---- Meet banner pulse ---- */
.live-dot {
  width: 8px; height: 8px; border-radius: 9999px; background: #A23E2E;
  box-shadow: 0 0 0 0 rgba(162,62,46,0.6); animation: pulse 1.6s infinite;
}
@keyframes pulse {
  0%   { box-shadow: 0 0 0 0 rgba(162,62,46,0.55); }
  70%  { box-shadow: 0 0 0 8px rgba(162,62,46,0); }
  100% { box-shadow: 0 0 0 0 rgba(162,62,46,0); }
}

.card-hover { transition: transform 0.15s ease, box-shadow 0.15s ease; }
.card-hover:hover { transform: translateY(-1px); box-shadow: 0 6px 18px -8px rgba(22,48,43,0.15); }