app-header {
  display: block;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  overflow: hidden;

  & .app-header {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-sm) var(--space-lg);
    background: color-mix(in srgb, var(--color-surface) 85%, transparent);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
  }

  & .app-header__brand {
    text-decoration: none;
    color: var(--color-primary);
    font-weight: 700;
    font-size: var(--text-lg);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-md);
    transition: background 0.2s ease;
  }

  & .app-header__brand--active {
    background: color-mix(in srgb, var(--color-primary) 12%, transparent);
  }

  & .app-header__logo {
    height: 2rem;
    width: auto;
  }

  & .app-header__nav {
    flex: 1;
    display: flex;
    gap: var(--space-md);
  }

  & .app-header__link {
    text-decoration: none;
    color: var(--color-text);
    font-weight: 500;
    transition: color 0.2s ease;

    &:hover {
      color: var(--color-primary);
    }
  }

  & .app-header__actions {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
  }

  & .app-header__cart-link {
    text-decoration: none;
    color: inherit;
    position: relative;
    transition: color 0.2s ease;
  }

  & .app-header__cart-link--active {
    color: var(--color-primary);
  }

  & .app-header__user {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    font-size: var(--text-sm);
    color: var(--color-text-muted);
  }

  & .app-header__sign-out,
  & .app-header__sign-in {
    display: inline-flex;
    align-items: center;
    background: none;
    border: none;
    padding: 0;
    cursor: pointer;
    color: var(--color-text);

    &:hover {
      color: var(--color-primary);
    }
  }

  & .app-header__link--active {
    position: relative;

    &::after {
      content: '';
      position: absolute;
      bottom: -100%;
      left: 50%;
      transform: translateX(-50%);
      width: 20px;
      height: 20px;
      border-radius: 50%;
      background: var(--color-primary);
    }
  }

  @media (width <= 640px) {
    & region-select {
      display: none;
    }
  }
}