/* Page transition animation removed — it caused stacking context / compositing
   bugs on mobile that broke accordion panel rendering. */
/* =========================
   HEADER / NAV
========================= */

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  overflow: hidden; /* contains reading progress bar */
  background: rgba(255, 255, 255, 0.84);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(79, 70, 229, 0.10);
  transition: background 0.35s ease, border-color 0.35s ease;
}

/* Reading progress bar — injected via JS on note pages */
.reading-progress-bar {
  position: absolute;
  bottom: 0; left: 0;
  height: 2.5px;
  width: 0%;
  background: linear-gradient(90deg, var(--primary), var(--accent, #06B6D4));
  transition: width 80ms linear;
  pointer-events: none;
  opacity: 0;
}
.reading-progress-bar.is-active { opacity: 1; }

/* =========================
   BOTTOM NAV — MOBILE
========================= */

.hz-bottom-nav { display: none; }

/* Pages that suppress the bottom nav (e.g. full-screen lab pages) */
body.no-bottom-nav .hz-bottom-nav { display: none !important; }
@media (max-width: 760px) {
  body.no-bottom-nav { padding-bottom: 0 !important; }
}

@media (max-width: 760px) {
  .hz-bottom-nav {
    display: flex;
    position: fixed;
    bottom: 0; left: 0; right: 0;
    z-index: 50;
    height: calc(var(--bottom-nav-h) + var(--safe-bottom));
    padding-bottom: var(--safe-bottom);
    background: rgba(255, 253, 248, 0.94);
    border-top: 1px solid var(--line);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    align-items: stretch;
    justify-content: space-around;
  }
  .hz-bottom-nav-item {
    display: flex; flex-direction: column;
    align-items: center; justify-content: center;
    flex: 1; gap: 3px;
    font-size: 0.62rem; font-weight: 700;
    color: var(--muted);
    text-decoration: none;
    border: none; background: none; cursor: pointer;
    padding: 0; transition: color 0.15s;
    letter-spacing: 0.01em;
    -webkit-tap-highlight-color: transparent;
  }
  .hz-bottom-nav-item.is-active { color: var(--primary); }
  .hz-bottom-nav-item .hz-nav-icon {
    display: flex; align-items: center; justify-content: center;
    width: 22px; height: 22px;
  }
  .hz-bottom-nav-item .hz-nav-icon svg { width: 22px; height: 22px; }
  /* Body padding — content not hidden behind bottom nav */
  body { padding-bottom: calc(var(--bottom-nav-h) + var(--safe-bottom)); }
  /* Hide hamburger — bottom nav replaces it on mobile */
  .nav-toggle { display: none !important; }
  /* Hide header dark-mode FAB on mobile — it lives in bottom nav now */
  .nav-wrap .display-fab { display: none !important; }
}

[data-theme="dark"] .hz-bottom-nav {
  background: rgba(13, 15, 26, 0.96);
  border-top-color: rgba(129, 140, 248, 0.12);
}


.nav-wrap {
  position: relative;
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  font-size: 1.02rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  transition: color 0.2s ease;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 1.1rem;
}

.site-nav a {
  color: var(--muted);
  font-weight: 700;
  transition: color 0.2s ease;
}

.site-nav a:hover {
  color: var(--ink);
}

.nav-toggle {
  display: none;
  border: 1px solid var(--line-strong);
  background: var(--paper);
  border-radius: 12px;
  padding: 0.5rem 0.75rem;
  cursor: pointer;
  transition: background 0.2s ease, border-color 0.2s ease, transform 0.15s ease;
}

.nav-toggle:hover {
  transform: scale(1.05);
}

/* =========================
   DARK MODE TOGGLE
========================= */

.display-fab {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 12px;
  border: 1px solid var(--line-strong);
  background: var(--paper);
  cursor: pointer;
  font-size: 1.1rem;
  line-height: 1;
  flex-shrink: 0;
  transition: background 0.2s ease, border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.display-fab:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-soft);
}



.eyebrow {
  margin: 0 0 0.6rem;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--primary);
}

h1, h2, h3 {
  margin: 0 0 0.7rem;
  line-height: 1.12;
  letter-spacing: -0.025em;
  color: var(--ink);
  transition: color 0.35s ease;
}

h1 {
  font-size: clamp(2.15rem, 4vw, 3.6rem);
}

h2 {
  font-size: clamp(1.35rem, 2vw, 1.9rem);
}

h3 {
  font-size: 1rem;
}

.lead {
  margin: 0;
  max-width: 62ch;
  color: var(--muted);
  font-size: 1rem;
  line-height: 1.75;
  transition: color 0.35s ease;
}

.card-kicker,
.preview-label {
  margin: 0 0 0.55rem;
  font-size: 0.76rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.point-heading {
  margin: 0 0 0.72rem;
  font-size: 0.96rem;
  font-weight: 900;
  color: var(--ink);
  letter-spacing: -0.01em;
  line-height: 1.35;
  transition: color 0.35s ease;
}

.point-line {
  margin: 0.72rem 0 0;
  color: var(--muted);
  font-size: 0.99rem;
  line-height: 1.7;
  transition: color 0.35s ease;
}

/* =========================
   FOOTER
========================= */

.site-footer {
  padding: 1.8rem 0 2.6rem;
  border-top: 1px solid rgba(79, 70, 229, 0.10);
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.80), rgba(240, 241, 255, 0.72));
  backdrop-filter: blur(10px);
  transition: background 0.35s ease, border-color 0.35s ease;
}


.footer-wrap { display: flex; align-items: flex-start; justify-content: space-between; gap: 1rem; }
.footer-brand { margin: 0 0 0.35rem; font-weight: 800; }
.footer-links { display: flex; flex-wrap: wrap; gap: 1rem; color: var(--muted); }
.footer-links a { transition: color 0.2s ease; }
.footer-links a:hover { color: var(--ink); }
.footer-bottom {
  margin-top: 1.4rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(92, 110, 132, 0.10);
  text-align: center;
  font-size: 0.78rem;
  color: var(--muted);
  opacity: 0.75;
}

/* =========================
   ANIMATION
========================= */

@keyframes fadeSlide {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}