Astro was designed to make styling and writing CSS a breeze. Write your own CSS directly inside of an Astro component or import your favorite CSS library like Tailwind. Advanced styling languages like Sass and Less are also supported.

Styling an Astro component is as easy as adding a tag to your component or page template. When you place a tag inside of an Astro component, Astro will detect the CSS and handle your styles for you, automatically.

Astro CSS rules are automatically scoped by default. Scoped styles are compiled behind-the-scenes to only apply to HTML written inside of that same component. The CSS that you write inside of an Astro component is automatically encapsulated inside of that component.

This CSS:

Compiles to this:

Scoped styles don’t leak and won’t impact the rest of your site. In Astro, it is okay to use low-specificity selectors like h1 {} or p {} because they will be compiled with scopes in the final output.

Scoped styles also won’t apply to other Astro components contained inside of your template. If you need to style a child component, consider wrapping that component in a (or other element) that you can then style.

The specificity of scoped styles is preserved, allowing them to work consistently alongside other CSS files or CSS libraries while still preserving the exclusive boundaries that prevent styles from applying outside the component.

While we recommend scoped styles for most components, you may eventually find a valid reason to write global, unscoped CSS. You can opt-out of automatic CSS scoping with the attribute.

You can also mix global & scoped CSS rules together in the same tag using the :global() selector. This becomes a powerful pattern for applying CSS styles to children of your component.

This is a great way to style things like blog posts, or documents with CMS-powered content where the contents live outside of Astro. But be careful: components whose appearance differs based on whether or not they have a certain parent component can become difficult to troubleshoot.

Scoped styles should be used as often as possible. Global styles should be used only as-needed.

If you need to combine classes on an element dynamically, you can use the class:list utility attribute in .astro files.

Added in:astro@0.21.0

The Astro can reference any CSS variables available on the page. You can also pass CSS variables directly from your component frontmatter using the define:vars directive.

In Astro, HTML attributes like class do not automatically pass through to child components.

Instead, accept a class prop in the child component and apply it to the root element. When destructuring, you must rename it, because class is a reserved word in JavaScript.

Using the default scoped style strategy, you must also pass the data-astro-cid-* attribute. You can do this by passing the ...rest of the props to the component. If you have changed scopedStyleStrategy to 'class' or 'where', the ...rest prop is not necessary.

Scoped styles from parent components

Because the data-astro-cid-* attribute includes the child in its parent’s scope, it is possible for styles to cascade from parent to child. To avoid this having unintended side effects, ensure you use unique class names in the child component.

You can style HTML elements inline using the style attribute. This can be a CSS string or an object of CSS properties:

There are two ways to resolve external global stylesheets: an ESM import for files located within your project source, and an absolute URL link for files in your public/ directory, or hosted outside of your project.

Using an npm package?

You may need to update your astro.config when importing from npm packages. See the “import stylesheets from an npm package” section below.

You can import stylesheets in your Astro component frontmatter using ESM import syntax. CSS imports work like any other ESM import in an Astro component, which should be referenced as relative to the component and must be written at the top of your component script, with any other imports.

CSS import via ESM are supported inside of any JavaScript file, including JSX components like React & Preact. This can be useful for writing granular, per-component styles for your React components.

You may also need to load stylesheets from an external npm package. This is especially common for utilities like Open Props. If your package recommends using a file extension (i.e. package-name/styles.css instead of package-name/styles), this should work like any local stylesheet:

If your package does not suggest using a file extension (i.e. package-name/styles), you’ll need to update your Astro config first!

Say you are importing a CSS file from package-name called normalize (with the file extension omitted). To ensure we can prerender your page correctly, add package-name to the vite.ssr.noExternal array:

Note

This is a Vite-specific setting that does not relate to (or require) Astro SSR.

Now, you are free to import package-name/normalize. This will be bundled and optimized by Astro like any other local stylesheet.

You can also use the element to load a stylesheet on the page. This should be an absolute URL path to a CSS file located in your /public directory, or an URL to an external website. Relative href values are not supported.

Because this approach uses the public/ directory, it skips the normal CSS processing, bundling and optimizations that are provided by Astro. If you need these transformations, use the Import a Stylesheet method above.

Astro components will sometimes have to evaluate multiple sources of CSS. For example, your component might import a CSS stylesheet, include its own tag, and be rendered inside a layout that imports CSS.

When conflicting CSS rules apply to the same element, browsers first use specificity and then order of appearance to determine which value to show.

If one rule is more specific than another, no matter where the CSS rule appears, its value will take precedence:

If two rules have the same specificity, then the order of appearance is evaluated, and the last rule’s value will take precedence:

Astro CSS rules are evaluated in this order of appearance:

Using scoped styles does not increase the specificity of your CSS, but they will always come last in the order of appearance. They will therefore take precedence over other styles of the same specificity. For example, if you import a stylesheet that conflicts with a scoped style, the scoped style’s value will apply:

If you make the imported style more specific, it will have higher precedence over the scoped style:

When importing multiple stylesheets in an Astro component, the CSS rules are evaluated in the order that they are imported. A higher specificity will always determine which styles to show, no matter when the CSS is evaluated. But, when conflicting styles have the same specificity, the last one imported wins:

While tags are scoped and only apply to the component that declares them, imported CSS can “leak”. Importing a component applies any CSS it imports, even if the component is never used:

Tip

A common pattern in Astro is to import global CSS inside a Layout component. Be sure to import the Layout component before other imports so that it has the lowest precedence.

Style sheets loaded via link tags are evaluated in order, before any other styles in an Astro file. Therefore, these styles will have lower precedence than imported stylesheets and scoped styles:

Astro comes with support for adding popular CSS libraries, tools, and frameworks to your project like Tailwind and more!

To use Tailwind in your project, install the official Astro Tailwind integration using the astro add command for your package manager:

Astro supports CSS preprocessors such as Sass, Stylus, and Less through Vite.

Use or in .astro files.

Use or in .astro files.

Use in .astro files.

Update your vite configuration in astro.config.mjs:

You can also use all of the above CSS preprocessors within JS frameworks as well! Be sure to follow the patterns each framework recommends:

Astro comes with PostCSS included as part of Vite. To configure PostCSS for your project, create a postcss.config.cjs file in the project root. You can import plugins using require() after installing them (for example npm install autoprefixer).

.jsx files support both global CSS and CSS Modules. To enable the latter, use the .module.css extension (or .module.scss/.module.sass if using Sass).

Vue in Astro supports the same methods as vue-loader does:

Svelte in Astro also works exactly as expected: Svelte Styling Docs.

Any Astro styling methods are available to a Markdown layout component, but different methods will have different styling effects on your page.

You can apply global styles to your Markdown content by adding imported stylesheets to the layout that wraps your page content. It is also possible to style your Markdown with tags in the layout component. Note that any styles added are subject to Astro’s cascading order, and you should check your rendered page carefully to ensure your styles are being applied as intended.

You can also add CSS integrations including Tailwind. If you are using Tailwind, the typography plugin can be useful for styling Markdown.

When Astro builds your site for production deployment, it minifies and combines your CSS into chunks. Each page on your site gets its own chunk, and additionally, CSS that is shared between multiple pages is further split off into their own chunks for reuse.

However, when you have several pages sharing styles, some shared chunks can become really small. If all of them were sent separately, it would lead to many stylesheets requests and affect site performance. Therefore, by default Astro will link only those in your HTML above 4kB in size as tags, while inlining smaller ones into . This approach provides a balance between the number of additional requests and the volume of CSS that can be cached between pages.

You can configure the size at which stylesheets will be linked externally (in bytes) using the assetsInlineLimit vite build option. Note that this option affects script and image inlining as well.

If you would rather all project styles remain external, you can configure the inlineStylesheets build option.

You can also set this option to 'always' which will inline all stylesheets.

Caution

Be careful when bypassing Astro’s built-in CSS bundling! Styles won’t be automatically included in the built output, and it is your responsibility to make sure that the referenced file is properly included in the final page output.

For advanced use cases, CSS can be read directly from disk without being bundled or optimized by Astro. This can be useful when you need complete control over some snippet of CSS, and need to bypass Astro’s automatic CSS handling.

This is not recommended for most users.

See Vite’s docs for full details.

For advanced use cases, you can import a direct URL reference for a CSS file inside of your project src/ directory. This can be useful when you need complete control over how a CSS file is loaded on the page. However, this will prevent the optimization of that CSS file with the rest of your page CSS .

This is not recommended for most users. Instead, place your CSS files inside of public/ to get a consistent URL reference.

Caution

Importing a smaller CSS file with ?url may return the base64 encoded contents of the CSS file as a data URL in your final build. Either write your code to support encoded data URLs (data:text/css;base64,...) or set the vite.build.assetsInlineLimit config option to 0 to disable this feature.

See Vite’s docs for full details.