Responsive Styles doesn`t working

[toy-crane]

I use Responsive Styles props like that.

import React from "react";
import { ThemeProvider } from "emotion-theming";
import { Button } from "rebass";

const theme = {
	breakpoints: ["100px", "200px", "300px", "400px"],
};

function App() {
	return (
		<>
			<ThemeProvider theme={theme}>
				<Button variant="primary" sx={{ margin: [0, 1, 2, 3] }}>
					Beep
				</Button>
			</ThemeProvider>
		</>
	);
}

export default App;

but last element 400px doesn`t work.
is this bug?? or Am I using it wrong?

package version info

{
  "name": "responsive-rebass",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@testing-library/jest-dom": "^4.2.4",
    "@testing-library/react": "^9.3.2",
    "@testing-library/user-event": "^7.1.2",
    "emotion-theming": "^10.0.27",
    "react": "^16.13.1",
    "react-dom": "^16.13.1",
    "react-scripts": "3.4.1",
    "rebass": "^4.0.7"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  }
}