Step-by-Step Guide to Next.js Styled Components for Efficient Styling

Styled-components is a popular CSS-in-JS library that allows you to write CSS directly within your JavaScript, specifically within your React components. This approach leverages tagged template literals in ES6 to enable a seamless integration of styling and logic, making it easier to manage styles in a modular and scoped manner.

This library has gained popularity due to its ability to provide scoped styles, dynamic styling capabilities, and a more streamlined developer experience compared to traditional CSS.

Why Styled-components?

Styled-components has become a favorite in the React ecosystem for several reasons:

1. Scoped Styles: By defining styles directly within components, you eliminate the risk of global style conflicts and ensure that styles are applied only where intended.

2. Dynamic Styling: Styled-components allows you to use props to dynamically adjust styles based on component state or other variables, enhancing the flexibility and reusability of your components.

3. Enhanced Developer Experience: With features like automatic vendor prefixing and support for nesting, media queries, and theming, styled-components simplifies the styling process and reduces boilerplate code.

4. SSR Support: Styled-components also supports server-side rendering (SSR), which is crucial for performance and SEO in Next.js applications. This ensures that styles are correctly rendered on the server and sent to the client.

Setting Up a Next.js Project

Before you start, ensure you have the following prerequisites:

1. Node.js: Ensure that Node.js is installed on your machine. You can download it from the official Node.js website .

2. npm or yarn: These are package managers for JavaScript. npm comes bundled with Node.js, but you can also install yarn from its official website .

3. Basic Knowledge of React and Next.js: Familiarity with React concepts and Next.js will help you follow along with this guide more easily.

To check if Node.js and npm are installed, open your terminal and run the following commands:

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1node -v
2npm -v

For yarn, check its installation with:

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1yarn -v

Step-by-Step Guide

1. Open your terminal: Navigate to the directory where you want to create your project.

2. Run the create-next-app command: This command scaffolds a new Next.js project. Replace my-nextjs-app with your desired project name.

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1npx create-next-app my-nextjs-app

Alternatively, if you prefer to use yarn, you can run:

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1yarn create next-app my-nextjs-app

3. Navigate to your project directory: Change into the newly created project directory.

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1cd my-nextjs-app

4. Start the development server: Run the development server to verify that your project has been set up correctly.

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1npm run dev

If you're using yarn, the command is:

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1yarn dev

Open your browser and navigate to http://localhost:3000. You should see the Next.js welcome page, indicating that your project is up and running.

Installing Styled-components

To use styled-components in your Next.js project, you need to install the styled-components library and its peer dependency, babel-plugin-styled-components. Follow these steps to install them:

1. Open your terminal: Make sure you are in your Next.js project directory.

2. Install styled-components and babel-plugin-styled-components:

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1npm install styled-components
2npm install --save-dev babel-plugin-styled-components

If you are using yarn, run:

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1yarn add styled-components
2yarn add --dev babel-plugin-styled-components

Configuring Babel

To configure Babel to work with styled-components, you need to create or modify the Babel configuration file. Here’s how you can do it:

1. Create or open the .babelrc or babel.config.js file in the root directory of your project.

2. Add the styled-components plugin to the Babel configuration:

For .babelrc:

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1{
2  "presets": ["next/babel"],
3  "plugins": [["styled-components", { "ssr": true }]]
4}

For babel.config.js:

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1module.exports = {
2  presets: ['next/babel'],
3  plugins: [['styled-components', { ssr: true }]],
4};

By following these steps, you will have styled-components set up and ready to use in your Next.js project, enabling you to take advantage of scoped, dynamic styles and SSR support.

Setting Up Server-Side Rendering (SSR) with Styled-components in Next.js

Why SSR is Important?

Server-side rendering (SSR) is a key feature of Next.js that enhances performance and improves SEO by rendering your React components on the server before sending the HTML to the client. This results in faster initial load times and ensures that search engines can properly index your content. SSR is especially beneficial for large, dynamic applications where initial load time and SEO are critical.

Styled-components supports SSR by allowing styles to be rendered on the server and sent to the client as part of the initial HTML payload. This ensures that styles are available immediately upon page load, preventing the "flash of unstyled content" (FOUC). Additionally, SSR with styled-components helps in maintaining consistent styles across server and client, providing a seamless user experience.

Custom Document File

To enable SSR with styled-components in your Next.js application, you need to customize the _document.js file. This involves using ServerStyleSheet from styled-components to collect and inject styles during the server-side rendering process.

Step-by-Step Guide

1. Create or Modify document.js*: Create a new file named* document.js in the pages directory of your Next.js project if it doesn't already exist.

2. Import Required Modules: Import the necessary modules, including Document, DocumentContext, and ServerStyleSheet from styled-components.

3. Enhance the Document Class: Enhance the Document class to collect and inject styles during the server-side rendering process.

Here’s a step-by-step example:

1. Create or open _document.js in the pages directory:

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1import Document from 'next/document';
2import { ServerStyleSheet } from 'styled-components';
3
4class MyDocument extends Document {
5  static async getInitialProps(ctx) {
6    const sheet = new ServerStyleSheet();
7    const originalRenderPage = ctx.renderPage;
8
9    try {
10      ctx.renderPage = () =>
11        originalRenderPage({
12          enhanceApp: (App) => (props) =>
13            sheet.collectStyles(<App {...props} />),
14        });
15
16      const initialProps = await Document.getInitialProps(ctx);
17      return {
18        ...initialProps,
19        styles: (
20          <>
21            {initialProps.styles}
22            {sheet.getStyleElement()}
23          </>
24        ),
25      };
26    } finally {
27      sheet.seal();
28    }
29  }
30}
31
32export default MyDocument;

2. Explanation of the Code:

   • Import Statements: Import Document and ServerStyleSheet.

   • Custom Document Class: Create a custom MyDocument class extending Document.

   • getInitialProps: Override the getInitialProps method to collect styles from the server-rendered page.

   • ServerStyleSheet: Use ServerStyleSheet to collect all the styled-components styles from the components in the render tree.

   • Enhance App: Enhance the App component to include the collected styles.

   • Return Styles: Ensure the collected styles are included in the returned props and injected into the HTML.

Creating and Using Styled-components

Basic Usage

Creating Basic Styled-components

Styled-components allows you to define and use styled elements within your React components. You can create styled-components using the styled function from the styled-components library. This function generates a React component with styles attached to it.

Here’s a basic example of creating a styled button:

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1import styled from 'styled-components';
2
3const Button = styled.button`
4  padding: 10px 20px;
5  background-color: #0070f3;
6  color: white;
7  border: none;
8  border-radius: 5px;
9  cursor: pointer;
10
11  &:hover {
12    background-color: #005bb5;
13  }
14`;
15
16const App = () => {
17  return <Button>Click Me</Button>;
18};
19
20export default App;

In this example:

• We import styled from styled-components.

• We create a Button styled-component by calling styled.button and passing a template literal with CSS styles.

• We use the Button component in the App component, applying the defined styles.

Creating Styled Containers

You can also create styled containers and other elements similarly:

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1import styled from 'styled-components';
2
3const Container = styled.div`
4  display: flex;
5  flex-direction: column;
6  align-items: center;
7  justify-content: center;
8  padding: 20px;
9  background-color: #f0f0f0;
10  height: 100vh;
11`;
12
13const Title = styled.h1`
14  font-size: 2rem;
15  color: #333;
16`;
17
18const App = () => {
19  return (
20    <Container>
21      <Title>Welcome to Styled-components</Title>
22    </Container>
23  );
24};
25
26export default App;

This example demonstrates how to create a styled Container and Title component to structure and style your application layout.

Props and Dynamic Styling

Styled-components support dynamic styling based on props. This allows you to change styles dynamically based on component props, making your components more flexible and reusable.

Using Props for Dynamic Styling

To use props for dynamic styling, you can define styles as functions that receive props as arguments. Here’s an example:

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1import styled from 'styled-components';
2
3const Button = styled.button`
4  padding: 10px 20px;
5  background-color: ${(props) => (props.primary ? '#0070f3' : '#e0e0e0')};
6  color: ${(props) => (props.primary ? 'white' : '#333')};
7  border: none;
8  border-radius: 5px;
9  cursor: pointer;
10
11  &:hover {
12    background-color: ${(props) => (props.primary ? '#005bb5' : '#c0c0c0')};
13  }
14`;
15
16const App = () => {
17  return (
18    <>
19      <Button primary>Primary Button</Button>
20      <Button>Default Button</Button>
21    </>
22  );
23};
24
25export default App;

In this example:

• The Button component’s background and text color are determined by the primary prop.

• When the primary prop is true, the button has a blue background and white text. Otherwise, it has a light grey background and dark text.

More Examples of Dynamic Styling

Here’s another example showing how to change styles based on props:

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1import styled from 'styled-components';
2
3const Card = styled.div`
4  padding: 20px;
5  background-color: white;
6  border: 1px solid #ccc;
7  border-radius: 8px;
8  box-shadow: ${(props) => (props.shadow ? '0 4px 6px rgba(0, 0, 0, 0.1)' : 'none')};
9`;
10
11const App = () => {
12  return (
13    <>
14      <Card shadow>Card with Shadow</Card>
15      <Card>Card without Shadow</Card>
16    </>
17  );
18};
19
20export default App;

In this example:

• The Card component’s box shadow is determined by the shadow prop.

• When the shadow prop is true, the card has a shadow effect. Otherwise, it has no shadow.

Theming with Styled-components

Theming in styled-components allows you to define a set of global styles that can be applied consistently across your application. This is particularly useful for maintaining a unified look and feel, making it easy to manage and switch between different themes.

Creating a Theme File

To set up a theme, you first need to create a theme file where you can define your theme properties such as colors, fonts, and other design tokens.

1. Create a theme.js file: In your project, create a file named theme.js (or any other name you prefer) in a suitable directory, such as a styles or theme folder.

2. Define your theme properties: In the theme.js file, you can define various properties for your theme. Here’s an example:

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1// theme.js
2
3const theme = {
4  colors: {
5    primary: '#0070f3',
6    secondary: '#1c1c1e',
7    background: '#f0f0f0',
8    text: '#333',
9  },
10  fonts: {
11    main: 'Arial, sans-serif',
12    code: 'Courier, monospace',
13  },
14  fontSizes: {
15    small: '12px',
16    medium: '16px',
17    large: '20px',
18  },
19};
20
21export default theme;

In this example, we define a theme with color, font, and font size properties.

Using the ThemeProvider

To use the theme in your styled-components, you need to wrap your application with the ThemeProvider component provided by styled-components. This makes the theme available to all styled-components in your application.

Wrapping the Application with ThemeProvider

1. Import the necessary modules: Import ThemeProvider and your theme file in your main application file (e.g., pages/_app.js).

2. Wrap your application: Wrap your application’s root component with ThemeProvider and pass your theme as a prop.

Here’s how you can do it:

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1// pages/_app.js
2import { ThemeProvider } from 'styled-components';
3import theme from '../styles/theme';
4import GlobalStyle from '../styles/GlobalStyle';
5
6function MyApp({ Component, pageProps }) {
7  return (
8    <ThemeProvider theme={theme}>
9      <GlobalStyle />
10      <Component {...pageProps} />
11    </ThemeProvider>
12  );
13}
14
15export default MyApp;

In this example, we also import and apply global styles using the GlobalStyle component, which is a common practice to ensure basic styling is consistent across the entire application.

Accessing Theme Properties Within Styled-components

To use the theme properties within your styled-components, you can access the theme object from props. Here’s an example:

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1import styled from 'styled-components';
2
3const Button = styled.button`
4  padding: 10px 20px;
5  background-color: ${(props) => props.theme.colors.primary};
6  color: white;
7  font-family: ${(props) => props.theme.fonts.main};
8  border: none;
9  border-radius: 5px;
10  cursor: pointer;
11
12  &:hover {
13    background-color: ${(props) => props.theme.colors.secondary};
14  }
15`;
16
17const App = () => {
18  return <Button>Click Me</Button>;
19};
20
21export default App;

In this example:

• We use the theme object from props to set the background-color, font-family, and hover state of the Button component.

• This ensures that the Button component adheres to the theme defined in the theme.js file.

Advanced Usage of Styled-components

Global Styles

Global styles are CSS rules that apply to the entire application, regardless of the component structure. With styled-components, you can define global styles using the createGlobalStyle function. This is particularly useful for setting base styles, such as resetting default browser styles or applying consistent typography across your application.

Creating and Using Global Styles

To create global styles, follow these steps:

1. Import createGlobalStyle from styled-components.

2. Define your global styles using template literals.

3. Apply the global styles in your application by including the global style component at the root level.

Here’s an example:

1. Create a global style file (e.g., styles/GlobalStyle.js):

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1// styles/GlobalStyle.js
2import { createGlobalStyle } from 'styled-components';
3
4const GlobalStyle = createGlobalStyle`
5  * {
6    margin: 0;
7    padding: 0;
8    box-sizing: border-box;
9  }
10
11  body {
12    font-family: ${(props) => props.theme.fonts.main};
13    background-color: ${(props) => props.theme.colors.background};
14    color: ${(props) => props.theme.colors.text};
15    line-height: 1.6;
16  }
17
18  a {
19    text-decoration: none;
20    color: inherit;
21  }
22`;
23
24export default GlobalStyle;

2. Apply the global styles in your _app.js file:

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1// pages/_app.js
2import { ThemeProvider } from 'styled-components';
3import GlobalStyle from '../styles/GlobalStyle';
4import theme from '../styles/theme';
5
6function MyApp({ Component, pageProps }) {
7  return (
8    <ThemeProvider theme={theme}>
9      <GlobalStyle />
10      <Component {...pageProps} />
11    </ThemeProvider>
12  );
13}
14
15export default MyApp;

In this example, the GlobalStyle component sets default styles for all elements (*), the body, and links (a). These styles are applied globally across your application, ensuring consistent styling.

Extending Styles

Styled-components allows you to extend the styles of existing components, enabling reusability and the creation of component variants without duplicating code.

Extending Existing Styled-components

To extend an existing styled-component, you can use the styled function and pass the existing component to it. Here’s how you can extend styles:

1. Create a base component with some styles.

2. Create a new component that extends the base component’s styles and adds new styles.

Here’s an example:

1. Define a base button component:

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1import styled from 'styled-components';
2
3const Button = styled.button`
4  padding: 10px 20px;
5  background-color: ${(props) => props.theme.colors.primary};
6  color: white;
7  border: none;
8  border-radius: 5px;
9  cursor: pointer;
10
11  &:hover {
12    background-color: ${(props) => props.theme.colors.secondary};
13  }
14`;
15
16export default Button;

2. Extend the base button component to create a secondary button with additional styles:

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1import styled from 'styled-components';
2import Button from './Button';
3
4const SecondaryButton = styled(Button)`
5  background-color: white;
6  color: ${(props) => props.theme.colors.primary};
7  border: 2px solid ${(props) => props.theme.colors.primary};
8
9  &:hover {
10    background-color: ${(props) => props.theme.colors.primary};
11    color: white;
12  }
13`;
14
15export default SecondaryButton;

In this example:

• The Button component is the base component with primary styles.

• The SecondaryButton component extends Button by using styled(Button) and overrides the background color, text color, and border. It also modifies the hover styles.

By extending components, you can easily create new components that share common styles but have their own unique modifications. This promotes reusability and consistency across your application.

Best Practices

1. Organize Your Styles: Keep your styled-components organized in a styles or components directory. Group related components together to make your project structure clean and maintainable.

2. Use Theme and Global Styles: Define a theme using ThemeProvider and use global styles to set base styles. This ensures consistency across your application and makes it easier to manage design changes.

3. Keep Components Modular: Break down your components into smaller, reusable styled-components. This makes your code more readable and easier to maintain.

4. Document Your Styles: Add comments and documentation to your styled-components to explain their purpose and usage. This is particularly helpful for larger teams and projects.

5. Use Linting and Formatting Tools: Integrate tools like ESLint and Prettier with plugins for styled-components to maintain a consistent code style and catch potential issues early.

6. Leverage TypeScript: If you’re using TypeScript, leverage its features to add type definitions to your styled-components for better type safety and developer experience.

7. Test Your Styles: Use testing libraries like Jest and jest-styled-components to write unit tests for your styled-components. This ensures that your styles behave as expected and reduces the risk of regressions.

Conclusion

In this blog post, we've explored the integration and usage of styled-components in a Next.js project. Here's a quick summary of the key points covered:

1. Introduction: We discussed what styled-components are and why they are popular in the React ecosystem, focusing on benefits like scoped CSS, dynamic styling, and theme support.

2. Setting Up a Next.js Project: We outlined the prerequisites and provided a step-by-step guide on creating a new Next.js project using create-next-app.

3. Installing Styled-components: We detailed the installation steps for styled-components and its peer dependencies, along with configuring Babel to work with styled-components.

4. Setting Up Server-Side Rendering (SSR): We explained the importance of SSR in Next.js, how styled-components handle it, and provided a guide to configuring _document.js for SSR.

5. Creating and Using Styled-components: We showed how to create basic styled-components and use props for dynamic styling, with examples of buttons and containers.

6. Theming with Styled-components: We guided you through setting up a theme, wrapping the application with ThemeProvider, and accessing theme properties within styled-components.

7. Advanced Usage: We covered global styles, extending styles for reusability, and provided best practices for organizing and maintaining styled-components in a Next.js project.

8. Debugging and Best Practices: We discussed common issues, performance tips, and best practices for using styled-components effectively.

Styled-components provide a powerful and flexible way to manage styles in your Next.js projects. By integrating styled-components, you can achieve a more modular, maintainable, and dynamic styling system that enhances both development experience and application performance.

Try It Out: If you haven't already, try implementing styled-components in your Next.js projects. Start with basic components and gradually explore advanced features like theming and SSR.