# Server-Side Rendering [English](./server-side-rendering.md) | [Русский](./server-side-rendering-ru.md) To prevent a theme flash on the initial page load, generate the root CSS class during SSR: ```js import {getRootClassName} from '@gravity-ui/uikit/server'; const theme = 'dark'; const rootClassName = getRootClassName({theme}); const html = `
`; ```