/* Barre latérale + nav flottante + footer (référence index) */
.nav-expanded {
  --rail-width: 260px;
}

.nav-rail {
  position: sticky;
  top: 0;
  left: 0;
  height: 100vh;
  width: var(--rail-width);
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 16px 12px;
  background: rgba(8, 12, 26, 0.85);
  border-right: 1px solid var(--border-subtle, rgba(255, 255, 255, 0.08));
  backdrop-filter: blur(18px);
  box-shadow: 10px 0 30px rgba(0, 0, 0, 0.3);
  transition: box-shadow 0.3s ease;
  z-index: 100;
  overflow: hidden;
}

.nav-expanded .nav-rail {
  box-shadow: 14px 0 36px rgba(0, 0, 0, 0.4);
}

.nav-rail__top {
  display: grid;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
}

.brand-logo {
  font-weight: 900;
  font-size: 1.25rem;
  letter-spacing: -0.05em;
  text-decoration: none;
  justify-self: center;
  background: linear-gradient(135deg, #fff, #94a3b8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  position: relative;
  padding: 10px 0;
}

.brand-logo::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%);
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: #06b6d4;
  box-shadow: 0 0 12px rgba(6, 182, 212, 0.75);
}

.nav-rail__brand {
  display: grid;
  grid-template-columns: auto;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
  justify-content: center;
}

.brand-icon {
  width: 48px;
  height: 48px;
  border-radius: 14px;
  border: 1px solid rgba(255, 255, 255, 0.15);
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.3);
  background: linear-gradient(135deg, #10b981, #3b82f6);
  display: grid;
  place-items: center;
  font-weight: 800;
  font-size: 1.1rem;
  color: #fff;
  flex-shrink: 0;
}

.brand-text {
  white-space: nowrap;
  display: none;
}

.nav-expanded .brand-text {
  opacity: 1;
  display: block;
}

.brand-text strong {
  font-size: 1rem;
  display: block;
  line-height: 1.3;
}

.brand-text small {
  color: var(--text-muted, #94a3b8);
  font-size: 0.8rem;
  display: block;
}

.nav-rail__links {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.nav-rail__primary {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.nav-rail__bottom {
  margin-top: auto;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.rail-icon--classeur,
.nav-float__icon.rail-icon--classeur {
  display: inline-block;
  line-height: 1;
  transform: translateY(1px) scale(0.93);
  transform-origin: center;
}

.nav-float__icon {
  display: inline-block;
  line-height: 1;
}

.rail-link {
  display: grid;
  grid-template-columns: auto;
  align-items: center;
  gap: 0;
  justify-content: center;
  padding: 12px;
  border-radius: 14px;
  color: var(--text-muted, #94a3b8);
  text-decoration: none;
  background: transparent;
  border: 1px solid transparent;
  transition: all 0.2s ease;
  font-size: 0.9rem;
  white-space: nowrap;
  position: relative;
}

.rail-icon {
  font-size: 1.3rem;
  flex-shrink: 0;
}

.rail-label {
  display: none;
}

.nav-expanded .rail-label {
  opacity: 1;
  display: block;
}

.nav-expanded .nav-rail__brand,
.nav-expanded .rail-link {
  grid-template-columns: auto 1fr;
  gap: 12px;
  justify-content: flex-start;
}

.rail-link:hover,
.rail-link.is-active {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.12);
  color: #fff;
  transform: translateX(4px);
}

.rail-link.is-active {
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.15), rgba(59, 130, 246, 0.15));
  border-color: rgba(59, 130, 246, 0.3);
}

/* Canon rail (opt-in) — aligné avec le rendu chapitres/classeur */
.nav-rail--canon {
  background: rgba(2, 6, 23, 0.6);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-right: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow: 14px 0 38px rgba(0, 0, 0, 0.45);
  font-family: 'Inter', system-ui, sans-serif;
  padding: 28px 5px;
  gap: 20px;
  z-index: 50;
  will-change: width;
  transition:
    width 420ms cubic-bezier(0.34, 1.56, 0.64, 1),
    box-shadow 420ms cubic-bezier(0.4, 0, 0.2, 1),
    background 420ms cubic-bezier(0.4, 0, 0.2, 1),
    border-color 420ms cubic-bezier(0.4, 0, 0.2, 1);
}

.nav-rail--canon .nav-rail__top {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  margin-bottom: 20px;
  position: relative;
}

.nav-rail--canon .nav-rail__links {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 6px 4px;
}

.nav-rail--canon .rail-link {
  display: grid;
  grid-template-columns: 40px 1fr;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: 16px;
  color: #94a3b8;
  text-decoration: none;
  transition:
    transform 320ms cubic-bezier(0.34, 1.56, 0.64, 1),
    background 200ms ease,
    border-color 200ms ease,
    color 200ms ease,
    box-shadow 260ms ease;
  position: relative;
  border: 1px solid transparent;
}

.nav-rail--canon .rail-link:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.05);
}

.nav-rail--canon .rail-link.is-active {
  color: #fff;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.1), rgba(255, 255, 255, 0.02));
  border: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 0 20px rgba(139, 92, 246, 0.15);
}

.nav-rail--canon .rail-link.is-active::before,
.nav-rail--canon .rail-link:hover::before {
  content: '';
  position: absolute;
  left: -16px;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 24px;
  background: #8b5cf6;
  border-radius: 0 4px 4px 0;
  box-shadow: 0 0 10px rgba(139, 92, 246, 0.9);
}

.nav-rail--canon .rail-icon {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  background: rgba(255, 255, 255, 0.04);
  font-size: 1.3rem;
}

.nav-rail--canon .rail-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  white-space: nowrap;
}

/* État "collapsed" (wrapper non-expanded) — labels cachés sans casser la géométrie */
[data-nav-shell]:not(.nav-expanded) .nav-rail--canon .rail-link {
  grid-template-columns: 1fr;
  justify-items: center;
  padding: 10px;
}

[data-nav-shell]:not(.nav-expanded) .nav-rail--canon .rail-link::before {
  left: 50%;
  top: 6px;
  width: 18px;
  height: 3px;
  border-radius: 999px;
  transform: translateX(-50%);
}

[data-nav-shell]:not(.nav-expanded) .nav-rail--canon .rail-label {
  opacity: 0;
  transform: translateX(-10px);
  filter: blur(6px);
  pointer-events: none;
  transition:
    opacity 160ms ease,
    transform 320ms cubic-bezier(0.4, 0, 0.2, 1),
    filter 320ms cubic-bezier(0.4, 0, 0.2, 1);
}

[data-nav-shell].nav-expanded .nav-rail--canon .rail-label {
  opacity: 1;
  transform: translateX(0);
  filter: blur(0);
  pointer-events: auto;
  transition-delay: 80ms;
}

[data-nav-shell]:not(.nav-expanded) .nav-rail--canon .rail-label {
  position: absolute;
  left: 66px;
  top: 50%;
  transform: translateY(-50%) translateX(-6px);
}

/* Expanded: petite translation vers la droite (comme chapitres/classeur) */
[data-nav-shell].nav-expanded .nav-rail--canon .rail-link:hover,
[data-nav-shell].nav-expanded .nav-rail--canon .rail-link.is-active {
  transform: translateX(4px);
}

/* Fallback CSS-only (si JS ne tourne pas) */
@supports selector(:has(*)) {
  [data-nav-shell]:has(.nav-rail--canon:hover),
  [data-nav-shell]:has(.nav-rail--canon:focus-within) {
    --rail-width: 260px;
  }

  [data-nav-shell]:has(.nav-rail--canon:hover) .nav-rail--canon .rail-label,
  [data-nav-shell]:has(.nav-rail--canon:focus-within) .nav-rail--canon .rail-label {
    opacity: 1;
    transform: translateX(0);
    pointer-events: auto;
    position: static;
  }

  [data-nav-shell]:has(.nav-rail--canon:hover) .nav-rail--canon .rail-link,
  [data-nav-shell]:has(.nav-rail--canon:focus-within) .nav-rail--canon .rail-link {
    grid-template-columns: 40px 1fr;
    justify-items: start;
    padding: 10px 12px;
  }
}

/* Nav flottante mobile */
.nav-float {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(16px);
  border: 1px solid var(--border-subtle, rgba(255, 255, 255, 0.08));
  padding: 10px clamp(14px, 4vw, 20px);
  border-radius: 100px;
  display: none;
  gap: clamp(12px, 4vw, 24px);
  box-shadow: 0 20px 40px rgba(0,0,0,0.4);
  z-index: 100;
}

.nav-float--canon {
  max-width: min(96vw, 920px);
  overflow-x: auto;
  overscroll-behavior-x: contain;
  -webkit-overflow-scrolling: touch;
}

.nav-float--canon::-webkit-scrollbar {
  height: 0;
}

.nav-float a {
  display: grid;
  place-items: center;
  color: var(--text-muted, #94a3b8);
  text-decoration: none;
  font-size: 1.2rem;
  transition: color 0.2s, transform 0.2s;
  flex: 0 0 auto;
}

.nav-float a:hover, .nav-float a.active {
  color: #fff;
  transform: translateY(-2px);
}

/* Footer */
.footer {
  margin-top: 80px;
  padding: 32px 20px;
  text-align: center;
  color: var(--text-muted, #94a3b8);
  font-size: 0.85rem;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.footer div {
  margin: 8px 0;
}

.footer a {
  color: var(--text-muted, #94a3b8);
  text-decoration: none;
  transition: color 0.2s;
}

.footer a:hover {
  color: #fff;
}

/* Breakpoint commun nav/float */
@media (max-width: 1024px) {
  .nav-rail {
    display: none;
  }

  .nav-float {
    display: flex;
  }
}