Since you're using the ES6 import syntax you may use the same syntax to import your stylesheet

import './App.css'

Also, you can wrap your class with :global to switch to the global scope (this mean CSS Module won't modulify it, eg: adding a random id next to it)

:global(.myclass) {
  background-color: red;
}
Answer from felixyadomi on Stack Overflow
🌐
Docureacten
docureacten.github.io › managing global styles and themes
Managing Global Styles and Themes | React.js: Learn Easily with Examples
In this section, we'll explore how to handle global styles and themes efficiently using different techniques available in the React ecosystem. Global styles are CSS rules that apply to the entire application, affecting all components unless specifically overridden.
Discussions

Is it ok to style a react app with a global CSS/SCSS file which lives outside of the whole app?
Yes. I do this and it's fine. People might say it's the wrong approach but customers don't care. More on reddit.com
🌐 r/reactjs
6
4
September 3, 2022
Global styles sheet for CSS modules?
If we have certain styles that are reused (buttons, card/container styling, h1/h2/h3... etc.), would we create a global style sheet with all of those stylings and include it in the App.js? I define main font sizes, font families and colors in a global CSS file but I create separate files for each component. What about if we have multiple variants of these: for example, a small button, a large button, etc? Would we have multiple classes for each of those variants in the global style sheet as well, or would we maybe have a separate style sheet called like buttons.module.css that we could include in our different components and import styles from? I would create a default Button component and define its style using a class like .Button in a file called Button.module.css. I would then create additional classes like .Large or .Small within the same file that can be dynamically added to the Button component based on some prop. My website's CSS needs some refactoring but here's what it looks like at the moment: https://github.com/jnsjknn/website/tree/master/styles More on reddit.com
🌐 r/reactjs
4
1
June 28, 2022
How to Create global styles with Styled components in react and next js and is it better to use combination of css files and styled component?
I started using Styled Components for my Next.js app. Exploring best practices for global styles using Styled Components. First part of the question is how to create global styles with Styled Compo... More on stackoverflow.com
🌐 stackoverflow.com
Where to store global css variables?
I use SASS with CSSModules. Then i keep global variables in different files I import in respective component. Oh, I see that you don’t want to do this. But I don’t think you can. Unless whichever SASS interpreter had a way to import a file together with every other file, which imho sounds incredibly wasteful. More on reddit.com
🌐 r/reactjs
10
11
June 17, 2018
🌐
Bobby Hadz
bobbyhadz.com › blog › react-set-global-css
Applying global CSS styles in a React app | bobbyhadz
April 7, 2024 - Global CSS should be imported in index.js to make sure it's loaded on all pages of your React app. Here is an example of an index.css file that declares 2 globally available classes.
🌐
Medium
medium.com › @toshvelaga › using-global-css-variables-in-react-js-216f03fcdc56
Using Global CSS variables in React JS | by Tosh Velaga | Medium
March 7, 2022 - Wanting to write DRY CSS I decided that I should create some global CSS variables and use them across the app instead of copying and pasting everywhere. This gives us the advantage such that if we need to tweak one of the colors, all we have to do is change the value in one file. First let me provide some background. There are a bunch of different ways to apply styling in a React app.
🌐
Reddit
reddit.com › r/reactjs › is it ok to style a react app with a global css/scss file which lives outside of the whole app?
r/reactjs on Reddit: Is it ok to style a react app with a global CSS/SCSS file which lives outside of the whole app?
September 3, 2022 -

Hi,

TLDR: Code at the end to see how I want to style my app. Doable approach?

I am very new to react and now I need styling. I have seen a lot of ways how people style their react app for instance:

  • css modules

  • styled components

  • tailwind ulitiy first

  • and so on...

The thing is that I dont like all of these solutions (except tailwind but I would use that on top of my styles). I dont see a reason why I should bloat my JS components with styling at all.

So my approach would be like this:

My react components just set class names like class="MyComp__wrap". Then I would style that selector "MyComp__wrap" in an external css/scss file. In my index.html I would just include that css file very early, even before the app is loaded. Just like this: "<link rel="stylesheet" href="/css/index.css">" Almost the same approach would be if I include this css file in the first react app js file (right before "ReactDOM.createRoot") like this "import './css/.index.css';" - But I dont see the reason why I should load the CSS from the react app if I can just do it in the index.html

I think its a super easy approach which does not reinvent the wheel. The components are not bloatet with styles only classNames. Furthermore it reduces complexity because the app does not even know that styling is applied. Classes wouldnt clash because of the nameing schema BEM.

I like this version a lot but of course I dont want to go down a road which is completely against all standards. What do you think?


index.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1" />
    <link rel="stylesheet" href="/css/index.css">
    <title>React App</title>
  </head>
  <body>
    <div id="root"></div>
    <script src="/js/react-app-build.js"></script>
  </body>
</html>

index.js

or I would import the /css/index.css here (but I dont see a reason to do that at the moment therefore I would just stick to the index.html solution):

import './css/index.css'
import React from 'react';
import ReactDOM from 'react-dom/client';
import App from './App';
const root = ReactDOM.createRoot(document.getElementById('root'));

root.render(
    <App />
);

SomeReactComp.js

const SomeReactComp = (props) => {
    return (
        <div className='SomeReactComp__wrap'></div>
    );
}

export default SomeReactComp;

css/index.css

.SomeReactComp__wrap {
    backrgound: grey;
}
🌐
Medium
johannblake.medium.com › global-css-in-react-apps-25f846e7b79e
Global CSS with Material-UI Done Correctly in React Apps | by Johann Blake | Medium
March 7, 2020 - The following code, which is launched in your index.js file, loads the css file and parses the css data: ... This is necessary to help React identify the $ character that is reserved for jQuery. The final step is to use the globalCss variable in a React component that will be applied to the entire app.
Find elsewhere
🌐
LearnVern
learnvern.com › react js for web development › global css in react
What is Global CSS in React? - Learn with Experts
Import the main React entry file's global LESS / CSS stylesheet.
Published   October 30, 2021
🌐
Scalablecss
scalablecss.com › styled-components-global-styles
How to Create Global Styles with Styled Components - Scalable CSS
June 2, 2020 - This is just an example, and you might structure the top of your React tree differently, like this: ... The important thing to remember is to place the GlobalStyle component as a sibling component to your main application component(s). And that’s it! Global styling is now all set up with Styled Components. Levelling up your React and CSS ...
🌐
Reddit
reddit.com › r/reactjs › global styles sheet for css modules?
r/reactjs on Reddit: Global styles sheet for CSS modules?
June 28, 2022 -

Relatively new react dev here. I am using css modules in one of my projects. I am familiar basically with how it works, but I have a few questions when it comes to reusable code. If we have certain styles that are reused (buttons, card/container styling, h1/h2/h3... etc.), would we create a global style sheet with all of those stylings and include it in the App.js? What about if we have multiple variants of these: for example, a small button, a large button, etc? Would we have multiple classes for each of those variants in the global style sheet as well, or would we maybe have a separate style sheet called like buttons.module.css that we could include in our different components and import styles from? I guess in general I'm just confused about how to organize the styling of an entire app with css modules. If anyone has a link to a well architected, large code base that uses CSS modules that would be very helpful also, thanks!

🌐
DEV Community
dev.to › codeprototype › configuring-both-css-modules-and-global-css-for-reactjs-in-webpack-4ci7
Configuring both CSS Modules and global CSS for ReactJS in Webpack - DEV Community
April 7, 2020 - I prefer to keep all common CSS style rules in a global CSS style, called app.css for example. For style rules that only pertain to a particular component, then I'd like to keep in a separate CSS module. However, I want to be able to use the same className everywhere.
🌐
DEV Community
dev.to › diballesteros › how-to-use-global-mixins-and-variables-with-css-modules-in-react-with-sass-37ie
How to use global mixins and variables with CSS Modules in React with SASS - DEV Community
March 21, 2022 - Starting an app with Create-React-App or next a fairly common option is to use CSS Modules which guarantees that the styles per component will not have any conflicts, however, it does mean it’s slightly different to access these global variables.
🌐
Next.js
nextjs.org › learn › pages-router › assets-metadata-css-global-styles
Pages Router: Global Styles | Next.js
To load global CSS to your application, create a file called pages/_app.js with the following content: export default function App({ Component, pageProps }) { return <Component {...pageProps} />; } The default export of _app.js is a top-level ...
🌐
GeeksforGeeks
geeksforgeeks.org › reactjs › global-styling-with-styled-components-in-react
Global Styling with styled-components in React - GeeksforGeeks
July 23, 2025 - Usage: Import and render GlobalStyle in the main component for global styles. Utilize CustomButton different props for styling variations. ... "dependencies": { "@testing-library/jest-dom": "^5.17.0", "@testing-library/react": "^13.4.0", "@testing-library/user-event": "^13.5.0", "react": "^18.3.1", "react-dom": "^18.3.1", "react-scripts": "5.0.1", "styled-components": "^6.1.9", "web-vitals": "^2.1.4" } Example: Below example shows implementation of global styling using styled-components module
🌐
Max Rozen
maxrozen.com › guide-to-styling-react-app
Methods for styling your React app - Max Rozen
When I say styling, I mean writing your CSS styles more-or-less from scratch. If you're looking for pre-built components, I wrote a guide to commonly used React component libraries. Global CSS is likely the way you're used to styling webpages. You have a giant styles.css file, and try to write BEM or SMACSS names for all of your classes.
🌐
Syncfusion
syncfusion.com › blogs › react › top 7 ways to write css in your react or next.js app
Top 7 Ways to Write CSS in Your React or Next.js App
November 18, 2024 - This blog lists the top 7 ways to write CSS (cascading style sheets) in your React or NEXT.js applications in detail.
🌐
Josh W. Comeau
joshwcomeau.com › css › css-variables-for-react-devs
How to use CSS variables with React • Josh W. Comeau
April 13, 2020 - Instead of imperatively specifying ... that for us? ... const GlobalStyles = createGlobalStyle` html { --min-tap-target-height: 32px; @media (pointer: coarse) { --min-tap-target-height: 48px; } } `;...
🌐
Next.js
nextjs.org › learn-pages-router › basics › assets-metadata-css › global-styles
Global Styles - Assets, Metadata, and CSS
To load global CSS to your application, create a file called pages/_app.js with the following content: export default function App({ Component, pageProps }) { return <Component {...pageProps} />; } The default export of _app.js is a top-level ...
🌐
Reddit
reddit.com › r/reactjs › where to store global css variables?
r/reactjs on Reddit: Where to store global css variables?
June 17, 2018 -

Hey,

I set up my react project to support sass following this article, which worked out fine (I configured the webpack part slightly different though).

Since I will use a set of different colors throughout my application, I would like to store these into variables, which I can access from my components for example. Since I don't want to import my global.scss file everytime into every components .scss, I would like to somehow set the variables global, making them accessible without imports.

How could I achieve this?