Hooks for browser APIs, DOM events, viewport state, and client lifecycle behavior. ## Hooks [#hooks] Run a handler whenever the document is clicked. Create a stable callback that always sees the latest state. Attach typed listeners to window, document, or element refs. Track whether an element ref is currently hovered. Observe when an element enters or leaves a viewport/root. Detect whether code is running on the client. Check whether the component is still mounted. Use layout effect on client and effect on server. Subscribe to media query match state. Trigger handlers when interaction happens outside refs. Measure element size changes with ResizeObserver. Read `window.screen` values reactively. Load external scripts and track loading status. Lock and unlock scrolling on body or target elements. Run cleanup logic when a component unmounts. Track viewport width and height.