/* ============================================================
   Navigation Bar
   ============================================================ */

.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-nav);
  background: rgba(10, 14, 23, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
  transition: background var(--transition-normal);
}

[data-theme="light"] .site-nav {
  background: rgba(248, 250, 252, 0.85);
}

.site-nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
  height: 64px;
}

/* Logo */
.site-nav__logo {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  text-decoration: none;
}

.site-nav__logo-icon {
  width: 28px;
  height: 28px;
}

.site-nav__logo span {
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* Desktop links */
.site-nav__links {
  display: none;
  align-items: center;
  gap: var(--space-xs);
}

@media (min-width: 768px) {
  .site-nav__links { display: flex; }
}

.site-nav__link {
  padding: var(--space-xs) var(--space-md);
  color: var(--text-secondary);
  font-size: var(--text-sm);
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.site-nav__link:hover {
  color: var(--text-primary);
  background: rgba(139, 151, 176, 0.08);
}

.site-nav__link.active {
  color: var(--accent-primary);
}

/* Right-side actions */
.site-nav__actions {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

/* Theme toggle */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: none;
  border-radius: var(--radius-md);
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.theme-toggle:hover {
  color: var(--text-primary);
  background: rgba(139, 151, 176, 0.08);
}

.theme-toggle__icon--light,
.theme-toggle__icon--dark {
  width: 18px;
  height: 18px;
}

/* Show moon in dark mode, sun in light */
.theme-toggle__icon--light { display: none; }
.theme-toggle__icon--dark { display: block; }
[data-theme="light"] .theme-toggle__icon--light { display: block; }
[data-theme="light"] .theme-toggle__icon--dark { display: none; }

/* GitHub link */
.site-nav__github {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  color: var(--text-secondary);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.site-nav__github:hover {
  color: var(--text-primary);
  background: rgba(139, 151, 176, 0.08);
}

.site-nav__github svg {
  width: 20px;
  height: 20px;
}

/* Hamburger */
.hamburger {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  border: none;
  background: transparent;
  cursor: pointer;
  padding: 6px;
}

@media (min-width: 768px) {
  .hamburger { display: none; }
}

.hamburger__line {
  width: 100%;
  height: 2px;
  background: var(--text-secondary);
  border-radius: 2px;
  transition: all var(--transition-fast);
}

.hamburger.open .hamburger__line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.hamburger.open .hamburger__line:nth-child(2) {
  opacity: 0;
}

.hamburger.open .hamburger__line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Mobile menu */
.mobile-menu {
  display: none;
  position: fixed;
  top: 64px;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--bg-primary);
  z-index: calc(var(--z-nav) - 1);
  padding: var(--space-xl) var(--space-lg);
}

.mobile-menu.open {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.mobile-menu__link {
  display: block;
  padding: var(--space-md) var(--space-lg);
  color: var(--text-secondary);
  font-size: var(--text-lg);
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.mobile-menu__link:hover,
.mobile-menu__link.active {
  color: var(--accent-primary);
  background: rgba(56, 189, 248, 0.08);
}

/* ---- Dropdown menus ---- */
.site-nav__dropdown {
  position: relative;
}

.site-nav__dropdown-toggle {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: var(--space-xs) var(--space-md);
  color: var(--text-secondary);
  font-size: var(--text-sm);
  font-weight: 600;
  border: none;
  background: transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-family: inherit;
}

.site-nav__dropdown-toggle:hover {
  color: var(--text-primary);
  background: rgba(139, 151, 176, 0.08);
}

.site-nav__dropdown-toggle.active {
  color: var(--accent-primary);
}

.site-nav__chevron {
  width: 12px;
  height: 12px;
  transition: transform var(--transition-fast);
}

.site-nav__dropdown:hover .site-nav__chevron,
.site-nav__dropdown:focus-within .site-nav__chevron {
  transform: rotate(180deg);
}

.site-nav__dropdown-menu {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  min-width: 180px;
  padding: var(--space-xs);
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-prominent);
  z-index: calc(var(--z-nav) + 1);
  padding-top: calc(var(--space-xs) + 8px);
  /* Use opacity + visibility + pointer-events instead of display:none
     so we can add a transition-delay for comfortable mouse travel */
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.15s ease, visibility 0.15s ease;
  /* Keep the menu alive briefly after mouse leaves */
  transition-delay: 0.12s;
}

/* Transparent bridge to cover the gap between toggle and menu */
.site-nav__dropdown-menu::before {
  content: '';
  position: absolute;
  top: -12px;
  left: 0;
  right: 0;
  height: 12px;
}

.site-nav__dropdown:hover .site-nav__dropdown-menu,
.site-nav__dropdown:focus-within .site-nav__dropdown-menu {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transition-delay: 0.05s;
}

.site-nav__dropdown-item {
  display: block;
  padding: var(--space-sm) var(--space-md);
  color: var(--text-secondary);
  font-size: var(--text-sm);
  font-weight: 600;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.site-nav__dropdown-item:hover {
  color: var(--text-primary);
  background: rgba(139, 151, 176, 0.08);
}

.site-nav__dropdown-item.active {
  color: var(--accent-primary);
}

/* Pad main content below fixed nav */
body {
  padding-top: 64px;
}