Styled-jsx in Next.js: Writing CSS in JavaScript

Styled-jsx is a powerful feature in Next.js that allows you to write CSS directly in your JavaScript components. This approach, known as CSS-in-JS, enables you to scope styles to individual components, making it easier to manage styles in large and complex applications. In this article, we’ll explore how Styled-jsx works in Next.js, how to use it, and why it’s a game-changer for styling your application.

What is Styled-jsx?

Styled-jsx is a CSS-in-JS library that allows you to write CSS directly in your JavaScript components. The styles are scoped to the component, ensuring that they do not conflict with styles in other components. Styled-jsx is built into Next.js, making it easy to use without additional configuration.

How Styled-jsx Works in Next.js

In Next.js, Styled-jsx is enabled by default. To use Styled-jsx, simply add a <style jsx> tag to your component and write your CSS inside it. The styles will be automatically scoped to the component.

Example of Using Styled-jsx

Here’s an example of how to use Styled-jsx in a Next.js component:

// components/Button.js
export default function Button() {
  return (
    <button>
      Click me
      <style jsx>{`
        button {
          background-color: #0070f3;
          color: white;
          padding: 10px 20px;
          border: none;
          border-radius: 5px;
          cursor: pointer;
        }

        button:hover {
          background-color: #005bb5;
        }
      `}</style>
    </button>
  );
}

In this example, the styles are scoped to the Button component, ensuring that they do not conflict with other styles in the application.

Benefits of Styled-jsx

Styled-jsx offers several benefits:

• Scoped Styles: Styled-jsx automatically scopes styles to the component, preventing style conflicts.
• CSS-in-JS: Writing CSS directly in JavaScript makes it easier to manage styles in large and complex applications.
• Dynamic Styles: Styled-jsx allows you to dynamically generate styles using JavaScript.

Secrets and Hidden Facts

• Global Styles: You can use the <style jsx global> tag to define global styles.
• Dynamic Class Names: You can dynamically generate class names in Styled-jsx using JavaScript.
• Server-side Rendering: Styled-jsx supports server-side rendering, ensuring that styles are applied correctly on the server.

Conclusion

Styled-jsx is a powerful feature in Next.js that allows you to write CSS directly in your JavaScript components, improving maintainability and preventing style conflicts. Whether you’re building a small application or a large-scale project, Styled-jsx provides the tools and flexibility you need to create modular and reusable styles.