/* Header / Navigation */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-height);
  background-color: var(--color-nav-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.site-header__name {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-text);
  white-space: nowrap;
}

.site-header__name:hover {
  color: var(--color-accent);
}

/* Desktop nav */
.site-nav {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.site-nav__link {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  padding: var(--spacing-xs) 0;
  border-bottom: 2px solid transparent;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}

.site-nav__link:hover,
.site-nav__link--active {
  color: var(--color-text);
  border-bottom-color: var(--color-accent);
}

/* Theme toggle button */
.theme-toggle {
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-sm);
  color: var(--color-text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  transition: color var(--transition-fast), background-color var(--transition-fast);
}

.theme-toggle:hover {
  color: var(--color-text);
  background-color: var(--color-bg-alt);
}

.theme-toggle svg {
  width: 20px;
  height: 20px;
}

/* Hamburger button */
.hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--spacing-sm);
  color: var(--color-text);
  flex-direction: column;
  gap: 5px;
  align-items: center;
  justify-content: center;
}

.hamburger__line {
  display: block;
  width: 22px;
  height: 2px;
  background-color: currentColor;
  border-radius: 1px;
  transition: transform var(--transition-normal), opacity var(--transition-normal);
}

/* Hamburger open state */
.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 nav */
@media (max-width: 768px) {
  .hamburger {
    display: flex;
  }

  .site-nav {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background-color: var(--color-nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    align-items: stretch;
    padding: var(--spacing-md) var(--spacing-lg);
    gap: 0;
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: transform var(--transition-normal), opacity var(--transition-normal);
  }

  .site-nav--open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .site-nav__link {
    padding: var(--spacing-sm) 0;
    font-size: var(--font-size-base);
    border-bottom: none;
  }

  .theme-toggle {
    align-self: flex-start;
    margin-top: var(--spacing-sm);
  }
}