.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  border-bottom: 1px solid transparent;
  transition: background var(--dur-base), border-color var(--dur-base), box-shadow var(--dur-base);
}

.navbar.scrolled {
  background: var(--bg-glass-strong);
  backdrop-filter: blur(20px) saturate(160%);
  -webkit-backdrop-filter: blur(20px) saturate(160%);
  border-bottom-color: var(--border-glass);
  box-shadow: var(--shadow-sm);
}

.navbar-inner {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-lg);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-lg);
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-2xs);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.3rem;
  letter-spacing: -0.02em;
}

.brand-mark {
  width: 36px; height: 36px;
  border-radius: 11px;
  background: var(--gradient-primary);
  display: grid;
  place-items: center;
  box-shadow: var(--shadow-glow);
  flex-shrink: 0;
}
.brand-mark svg { width: 20px; height: 20px; }

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.nav-link {
  position: relative;
  padding: var(--space-2xs) var(--space-sm);
  font-size: var(--fs-body-sm);
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius-full);
  transition: color var(--dur-fast);
}
.nav-link:hover { color: var(--text-primary); }
.nav-link::after {
  content: "";
  position: absolute;
  left: var(--space-sm); right: var(--space-sm); bottom: 4px;
  height: 2px;
  background: var(--gradient-primary);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--dur-base) var(--ease-out-expo);
  border-radius: var(--radius-full);
}
.nav-link:hover::after { transform: scaleX(1); }

.nav-dropdown { position: relative; }
.nav-dropdown-panel {
  position: absolute;
  top: calc(100% + 14px);
  left: 50%;
  transform: translateX(-50%) translateY(8px);
  width: 560px;
  max-width: 90vw;
  padding: var(--space-md);
  border-radius: var(--radius-lg);
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 4px;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--dur-base) var(--ease-out-expo), transform var(--dur-base) var(--ease-out-expo), visibility var(--dur-base);
}
.nav-dropdown:hover .nav-dropdown-panel,
.nav-dropdown:focus-within .nav-dropdown-panel {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-md);
  transition: background var(--dur-fast);
}
.dropdown-item:hover { background: var(--gradient-primary-soft); }
.dropdown-item-icon {
  width: 34px; height: 34px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  background: var(--gradient-primary-soft);
  color: var(--color-primary);
  flex-shrink: 0;
}
.dropdown-item-icon svg { width: 17px; height: 17px; }
.dropdown-item-title { font-size: var(--fs-body-sm); font-weight: 600; }
.dropdown-item-desc { font-size: 0.75rem; color: var(--text-tertiary); }

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.theme-toggle {
  width: 42px; height: 42px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--bg-glass-strong);
  border: 1px solid var(--border-glass);
  transition: transform var(--dur-fast) var(--ease-spring), border-color var(--dur-fast);
  position: relative;
  overflow: hidden;
}
.theme-toggle:hover { transform: rotate(15deg); border-color: var(--color-primary); }
.theme-toggle svg { width: 18px; height: 18px; transition: opacity var(--dur-fast), transform var(--dur-base) var(--ease-spring); }
.theme-toggle .icon-sun { position: absolute; }
.theme-toggle .icon-moon { position: absolute; }
[data-theme="light"] .theme-toggle .icon-moon { opacity: 0; transform: rotate(90deg) scale(0.4); }
[data-theme="light"] .theme-toggle .icon-sun { opacity: 1; transform: rotate(0) scale(1); }
[data-theme="dark"] .theme-toggle .icon-sun { opacity: 0; transform: rotate(-90deg) scale(0.4); }
[data-theme="dark"] .theme-toggle .icon-moon { opacity: 1; transform: rotate(0) scale(1); }

.nav-burger {
  display: none;
  width: 42px; height: 42px;
  border-radius: 50%;
  background: var(--bg-glass-strong);
  border: 1px solid var(--border-glass);
  place-items: center;
  flex-direction: column;
  gap: 4px;
}
.nav-burger span {
  width: 18px; height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: transform var(--dur-base) var(--ease-out-expo), opacity var(--dur-fast);
}
.nav-burger.active span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.nav-burger.active span:nth-child(2) { opacity: 0; }
.nav-burger.active span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

.mobile-menu {
  position: fixed;
  top: var(--nav-height);
  left: 0; right: 0;
  bottom: 0;
  background: var(--bg-body);
  z-index: 999;
  padding: var(--space-lg);
  transform: translateY(-12px);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--dur-base) var(--ease-out-expo), transform var(--dur-base) var(--ease-out-expo), visibility var(--dur-base);
  overflow-y: auto;
}
.mobile-menu.open {
  transform: translateY(0);
  opacity: 1;
  visibility: visible;
}
.mobile-menu a {
  display: block;
  padding: var(--space-sm) var(--space-2xs);
  font-size: 1.15rem;
  font-weight: 600;
  font-family: var(--font-display);
  border-bottom: 1px solid var(--border-glass);
}

@media (max-width: 900px) {
  .nav-links { display: none; }
  .nav-burger { display: flex; }
}