state-based dropdown trigger styling

when a dropdown opens, its trigger should visually reflect that state. this gives users immediate feedback that the interaction is active, creating a clear spatial relationship between the trigger and content.

bind trigger styling to the dropdown's open state:

const [isOpen, setIsOpen] = useState(false);

<DropdownMenu open={isOpen} onOpenChange={setIsOpen}>
  <DropdownMenuTrigger asChild>
    <button
      className={`base-styles ${isOpen ? "opacity-80 bg-neutral-800/30" : ""}`}
    >
      trigger
    </button>
  </DropdownMenuTrigger>
  <DropdownMenuContent>{/* content */}</DropdownMenuContent>
</DropdownMenu>;

common patterns: reduce opacity (opacity-80), add background (bg-neutral-800/30), or combine both. use transitions for smooth state changes.