/*
 * RAXE Design System — Navigation
 * Main nav, mobile menu, breadcrumb, advisory back-nav.
 * Depends on: tokens.css, base.css
 */

/* ── Main nav ── */
.nav {
  position: sticky; top: 0; z-index: var(--z-nav);
  height: var(--nav-height);
  background: var(--surface-nav);
  backdrop-filter: blur(24px);
  border-bottom: 1px solid var(--border-default);
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 var(--container-pad);
}
.nav-left  { display: flex; align-items: center; gap: var(--space-10); }
.nav-right { display: flex; align-items: center; gap: var(--space-4); }

.nav-logo img { height: 27px; display: block; }

.nav-links { display: flex; align-items: center; gap: var(--space-7); }
.nav-link {
  font-size: var(--fs-caption); font-weight: var(--weight-medium);
  color: var(--text-muted); letter-spacing: 0.01em;
  transition: var(--transition-color);
}
.nav-link:hover  { color: var(--text-primary); }
.nav-link.active { color: var(--text-primary); }

/* ── Dropdown ── */
.nav-dropdown { position: relative; }
.nav-dropdown-toggle { display: flex; align-items: center; gap: 4px; }
.nav-chevron  { width: 12px; transition: transform var(--duration-fast) var(--ease-default); }
.nav-dropdown.open .nav-chevron { transform: rotate(180deg); }
.nav-dropdown-menu {
  position: absolute; top: calc(100% + 8px); left: 0;
  min-width: 180px;
  background: var(--surface-overlay); border: 1px solid var(--border-default);
  border-radius: var(--radius-lg); padding: var(--space-2);
  box-shadow: var(--shadow-lg);
  display: none; flex-direction: column; gap: 2px;
  z-index: var(--z-dropdown);
}
.nav-dropdown.open .nav-dropdown-menu { display: flex; }
.nav-dropdown-item {
  font-size: var(--fs-caption); color: var(--text-muted); font-weight: var(--weight-medium);
  padding: var(--space-2) var(--space-3); border-radius: var(--radius-md);
  transition: var(--transition-color);
}
.nav-dropdown-item:hover { color: var(--text-primary); background: rgba(56,189,248,0.06); }

/* ── Mobile menu toggle ── */
.mobile-menu-toggle {
  display: none; flex-direction: column; gap: 5px;
  padding: var(--space-2); cursor: pointer;
}
.hamburger-line {
  width: 22px; height: 2px; background: var(--text-muted); border-radius: 1px;
  transition: var(--transition-ui);
}
@media (max-width: 768px) {
  .mobile-menu-toggle { display: flex; }
  .nav-links { display: none; }
  .nav-links.open {
    display: flex; flex-direction: column;
    position: absolute; top: var(--nav-height); left: 0; right: 0;
    background: var(--surface-nav); border-bottom: 1px solid var(--border-default);
    padding: var(--space-4) var(--container-pad);
    gap: var(--space-4);
  }
}

/* ── Breadcrumb ── */
.breadcrumb { display: flex; align-items: center; gap: var(--space-2); }
.breadcrumb-item { font-size: var(--fs-label); color: var(--text-dim); }
.breadcrumb-item + .breadcrumb-item::before { content: '/'; margin-right: var(--space-2); }
.breadcrumb-item.current { color: var(--text-muted); }

/* ── Advisory back-nav ── */
.adv-nav {
  position: sticky; top: var(--nav-height); z-index: calc(var(--z-nav) - 1);
  height: var(--adv-nav-height);
  background: var(--surface-nav); backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-default);
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 var(--container-pad);
}
.adv-nav-back {
  font-family: var(--font-mono); font-size: 11px; color: var(--text-dim);
  display: flex; align-items: center; gap: var(--space-2);
  transition: var(--transition-color);
}
.adv-nav-back:hover { color: var(--text-brand); }
.adv-nav-id { font-family: var(--font-mono); font-size: 11px; color: var(--text-dim); letter-spacing: var(--tracking-wide); }

/* ── Back to top ── */
.back-to-top {
  position: fixed; bottom: var(--space-6); right: var(--space-6);
  z-index: var(--z-overlay);
  width: 40px; height: 40px; border-radius: 50%;
  background: var(--surface-overlay); border: 1px solid var(--border-strong);
  display: flex; align-items: center; justify-content: center;
  color: var(--text-brand); font-size: 16px;
  opacity: 0; pointer-events: none; transition: var(--transition-ui);
}
.back-to-top.visible { opacity: 1; pointer-events: auto; }
.back-to-top:hover { background: rgba(56,189,248,0.08); transform: translateY(-2px); }