ant-design/docs/react/compatible-style.en-US.md

order	title
6.5	CSS Compatible

Ant Design supports the last 2 versions of modern browsers. If you need to be compatible with legacy browsers, please perform downgrade processing according to actual needs:

Compatible adjustment

Ant Design default using CSS-in-JS with :where Selector to reduce priority to avoid user additional adjust style cost when updating. If you want to support old browser (or some other CSS framework selector priority conflict like TailwindCSS), you can use @ant-design/cssinjs to adjust this behavior (Please note keep version align with antd):

import { StyleProvider } from '@ant-design/cssinjs';

// Config `hashPriority` to `high` instead of default `low`
// Which will remove `:where` wrapper
export default () => (
  <StyleProvider hashPriority="high">
    <MyApp />
  </StyleProvider>
);

It will turn :where to class selector:

--  :where(.css-bAMboO).ant-btn {
++  .css-bAMboO.ant-btn {
      color: #fff;
    }

Note: After turning off the :where downgrade, you may need to manually adjust the priority of some styles. Or you can use PostCSS plugin to raise application css selector priority. PostCSS provides many plugins can help on this. e.g:

• postcss-scopify
• postcss-increase-specificity
• postcss-add-root-selector

Raise priority through plugin:

--  .my-btn {
++  #root .my-btn {
      background: red;
    }

CSS Logical Properties

To unify LTR and RTL styles, Ant Design uses CSS logical properties. For example, the original margin-left is replaced by margin-inline-start, so that it is the starting position spacing under both LTR and RTL. If you need to be compatible with older browsers, you can configure transformers through the StyleProvider of @ant-design/cssinjs:

import { StyleProvider, legacyLogicalPropertiesTransformer } from '@ant-design/cssinjs';

// `transformers` provides a way to transform CSS properties
export default () => (
  <StyleProvider transformers={[legacyLogicalPropertiesTransformer]}>
    <MyApp />
  </StyleProvider>
);

When toggled, styles will downgrade CSS logical properties:

.ant-modal-root {
-- inset: 0;
++ top: 0;
++ right: 0;
++ bottom: 0;
++ left: 0;
}

Rem Adaptation

In responsive web development, there is a need for a convenient and flexible way to achieve page adaptation and responsive design. The px2remTransformer transformer can quickly and accurately convert pixel units in style sheets to rem units relative to the root element (HTML tag), enabling the implementation of adaptive and responsive layouts.

import { StyleProvider, px2remTransformer } from '@ant-design/cssinjs';

const px2rem = px2remTransformer({
  rootValue: 32, // 32px = 1rem; @default 16
});

export default () => (
  <StyleProvider transformers={[px2rem]}>
    <MyApp />
  </StyleProvider>
);

The resulting transformed styles:

 .px2rem-box {
-  width: 400px;
+  width: 12.5rem;
   background-color: green;
-  font-size: 32px;
+  font-size: 1rem;
   border: 10PX solid #f0f;
 }

 @media only screen and (max-width: 600px) {
   .px2rem-box {
     background-color: red;
-    margin: 10px;
+    margin: 0.3125rem;
   }
 }

Options

Parameter	Description	Type	Default
rootValue	Font size of the root element	number	16
precision	Decimal places for the converted value	number	5
mediaQuery	Whether to convert px in media queries	boolean	false

For more details, please refer to: px2rem.ts#Options