Styling your application

Without any configuration, you can write CSS files and import them from your components. No magic, no tooling.

The simplest approach would be to import your stylesheet in your layout component. Imagine our templates all render inside BASE_DIR/components/Layout.tsx:

import React from "react";

import "@client/styles.css";

export const Layout = (props: {children: React.ReactNode}) => (
    <div className="layout">{props.children}</div>

And inside BASE_DIR/style.css write our styles:

.layout {
    width: 800px;
    margin: 0 auto;

No magic, no tooling. Just classic CSS.

Zero runtime CSS-in-JS

Classic CSS is fine, but it's not great. But we firmly believe the best approach is CSS-in-JS that statically compiles to a CSS stylesheet.

Vanilla Extract is one of the newer libraries in the space. Reactivated comes with built-in support. No extra tooling or configuration needed.

There is no colocation with Vanilla Extract. Styles need to be in a separate file. Still written in TypeScript though.

Our simple example would have @client/components/Banner.css.ts:

import {style} from "@vanilla-extract/css";

export const banner = style({
    background: "red",
    border: "1px solid black",

export const highlighted = style({
    backgroundColor: "blue",

And our @client/components/Banner.tsx:

import React from "react";

import {classNames} from "@reactivated";

import * as css from "./Banner.css";

export const Banner = (props: {
    children: React.React.Node;
    isHighlighted?: boolean;
}) => (
            props.isHighlighted === true && css.highlighted,

You can see Vanilla Extract encourages type safety and pure TypeScript usage. It has a powerful API.

Next steps

Be sure to read our request for comments to provide feedback.

Other tools

You can likely use JS-only CSS-in-JS libraries like emotion and styled-components.

So long as you stick their runtime-only, no-tooling offerings.