/* Shared site chrome — editorial study-guide aesthetic */
@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@500;600&display=swap');

:root {
  --site-ink: #1a1a1a;
  --site-muted: #5c5c5c;
  --site-border: #e5e2dc;
  --site-paper: #faf9f7;
  --site-accent: #1e3a5f;
  --site-accent-bright: #2563eb;
  --site-ref: #64748b;
  --site-video: #7c3aed;
}

html { scroll-padding-top: 4.25rem; }

/* ── Sticky top bar ── */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.65rem 1rem;
  margin: -0.5rem -1.5rem 1.5rem;
  padding: 0.7rem 1.5rem;
  background: rgba(250, 249, 247, 0.96);
  border-bottom: 1px solid var(--site-border);
  box-shadow: 0 1px 0 rgba(30, 58, 95, 0.04);
  backdrop-filter: blur(8px);
}

.site-nav-left,
.site-nav-right {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
}

.site-nav a { text-decoration: none; }

/* Hub chips — Home, Study Plan */
.nav-chip {
  display: inline-flex;
  align-items: center;
  padding: 0.38rem 0.8rem;
  border-radius: 6px;
  border: 1px solid var(--site-border);
  background: #fff;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--site-ink);
  transition: border-color 0.15s, color 0.15s, box-shadow 0.15s;
}

.nav-chip:hover {
  border-color: #93c5fd;
  color: var(--site-accent-bright);
  box-shadow: 0 1px 3px rgba(37, 99, 235, 0.08);
}

.nav-chip--plan {
  background: #eff6ff;
  border-color: #bfdbfe;
  color: #1d4ed8;
}

.nav-chip--plan:hover {
  background: #dbeafe;
  border-color: #93c5fd;
}

/* Step progress */
.progress-pill {
  font-family: 'IBM Plex Mono', Consolas, monospace;
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--site-accent);
  background: #eef2f6;
  padding: 0.28rem 0.55rem;
  border-radius: 4px;
  border: 1px solid #d4dce6;
}

/* Prev / Next — primary actions */
.nav-step {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.48rem 0.95rem;
  border-radius: 8px;
  font-size: 0.82rem;
  font-weight: 600;
  line-height: 1.2;
  transition: transform 0.12s, box-shadow 0.12s, opacity 0.12s;
}

.nav-step:hover { transform: translateY(-1px); }

.nav-step--prev {
  background: #fff;
  border: 1px solid var(--site-border);
  color: var(--site-ink);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
}

.nav-step--prev:hover {
  border-color: #94a3b8;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.06);
}

.nav-step--next {
  background: var(--site-accent);
  border: 1px solid #152a45;
  color: #fff;
  box-shadow: 0 2px 6px rgba(30, 58, 95, 0.22);
}

.nav-step--next:hover {
  background: #152a45;
  box-shadow: 0 3px 10px rgba(30, 58, 95, 0.28);
}

.nav-step-label {
  font-family: 'IBM Plex Mono', Consolas, monospace;
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  opacity: 0.75;
}

.nav-step--next .nav-step-label { opacity: 0.85; }

.nav-disabled,
.path-complete {
  font-size: 0.78rem;
  font-weight: 600;
  padding: 0.38rem 0.7rem;
  border-radius: 6px;
}

.nav-disabled {
  color: #a8a29e;
  border: 1px dashed #d6d3d1;
}

.path-complete {
  color: #065f46;
  background: #d1fae5;
  border: 1px solid #6ee7b7;
}

/* ── Source card (top of lesson) ── */
.lesson-source {
  margin: 0 0 1.35rem;
  padding: 1rem 1.2rem 1.05rem;
  background: linear-gradient(145deg, #f8fafc 0%, #f1f5f9 100%);
  border: 1px solid #dbe3ec;
  border-left: 3px solid var(--site-accent);
  border-radius: 0 8px 8px 0;
  font-size: 0.9rem;
  line-height: 1.55;
  color: var(--site-ink);
}

.lesson-source-label {
  font-family: 'IBM Plex Mono', Consolas, monospace;
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: #64748b;
  margin-bottom: 0.45rem;
}

.lesson-source-body a {
  color: var(--site-accent-bright);
  font-weight: 600;
  text-decoration: none;
  border-bottom: 1px solid rgba(37, 99, 235, 0.25);
}

.lesson-source-body a:hover {
  border-bottom-color: var(--site-accent-bright);
}

.subtitle { margin-bottom: 0.65rem !important; }
.lesson-source + .mission { margin-top: 0.85rem; }

/* ── Lesson footer ── */
.lesson-footer {
  margin-top: 3rem;
  padding-top: 0;
}

.lesson-footer-heading {
  font-family: 'IBM Plex Mono', Consolas, monospace;
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: #94a3b8;
  margin-bottom: 0.85rem;
}

.lesson-footer-path {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.85rem;
}

@media (max-width: 540px) {
  .lesson-footer-path { grid-template-columns: 1fr; }
}

.path-card {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 1rem 1.15rem;
  border-radius: 10px;
  border: 1px solid var(--site-border);
  background: #fff;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.15s, box-shadow 0.15s, transform 0.12s;
  min-height: 4.5rem;
}

.path-card:hover {
  border-color: #93c5fd;
  box-shadow: 0 4px 14px rgba(30, 58, 95, 0.08);
  transform: translateY(-2px);
}

.path-card--next {
  background: linear-gradient(145deg, #1e3a5f 0%, #152a45 100%);
  border-color: #152a45;
  color: #fff;
}

.path-card--next:hover {
  border-color: #0f2035;
  box-shadow: 0 6px 18px rgba(30, 58, 95, 0.25);
}

.path-card--empty {
  opacity: 0.45;
  pointer-events: none;
  background: #f9f8f6;
}

.path-card-kicker {
  font-family: 'IBM Plex Mono', Consolas, monospace;
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #94a3b8;
}

.path-card--next .path-card-kicker { color: rgba(255, 255, 255, 0.65); }

.path-card-title {
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.3;
}

.path-card--next .path-card-title { color: #fff; }

.lesson-footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-top: 1.35rem;
  padding-top: 1.15rem;
  border-top: 1px solid var(--site-border);
}

.footer-pill {
  display: inline-flex;
  align-items: center;
  padding: 0.4rem 0.75rem;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid transparent;
  transition: background 0.12s, border-color 0.12s;
}

.footer-pill--hub {
  background: #eff6ff;
  color: #1d4ed8;
  border-color: #bfdbfe;
}

.footer-pill--hub:hover { background: #dbeafe; }

.footer-pill--ref {
  background: #f8fafc;
  color: #475569;
  border-color: #e2e8f0;
}

.footer-pill--ref:hover {
  background: #f1f5f9;
  border-color: #cbd5e1;
}

.footer-pill--video {
  background: #f5f3ff;
  color: #6d28d9;
  border-color: #ddd6fe;
}

.footer-pill--video:hover { background: #ede9fe; }

.btn-continue {
  display: inline-block;
  padding: 0.55rem 1rem;
  border-radius: 6px;
  background: #7c3aed;
  color: #fff !important;
  font-weight: 600;
  text-decoration: none !important;
}

.btn-continue:hover { opacity: 0.9; }

@media (max-width: 640px) {
  .site-nav {
    margin-left: -1rem;
    margin-right: -1rem;
    padding-left: 1rem;
    padding-right: 1rem;
  }
  .site-nav-right { width: 100%; justify-content: flex-start; }
  .nav-step { flex: 1; justify-content: center; min-width: 0; }
  .nav-step span:last-child {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
}

@media print {
  .site-nav,
  .no-print,
  .ask,
  .quiz,
  .lesson-footer,
  .btn-continue-wrap { display: none !important; }
  body { padding-top: 0 !important; }
  .lesson-source { border: 1px solid #ccc; background: #fff; }
}