Learn how to implement a persistent light/dark theme toggle in React using a custom useLocalStorage hook and CSS variables. The solution stores user preferences in localStorage for persistence across page reloads, uses CSS custom properties for clean theme switching via data attributes, and includes a reusable hook pattern that can be applied to other persistent settings. The implementation features lazy initialization for performance, smooth transitions, and a maintainable architecture that separates concerns between React state management and CSS styling.
Table of contents
The custom hook: useLocalStorageSort: