Styled-components (CSS-in-JS):?

• CSS-in-JS allows writing actual CSS inside JavaScript files.
• Supports dynamic styling and theming.

import styled from 'styled-components';

const Button = styled.button`

background: ${(props) => (props.primary ? 'blue' : 'gray')};

color: white;

`;

function App() {

return <Button primary={true}>Click Me</Button>;
}