🐛 Bug Report

I have a simple setup using the classic theme in which I've modified the admonition styling.

In my case, I have only overridden the admonition class and admonition-tip|note|important classes. I didn't touch the alert class which is also used in the admonitions.

• When I build my output with yarn start I get this, which I what I expect:

• When I build my output with yarn build I get this, which is unexpected:

Somehow, the classes are not in the same order, which might be the reason (??).

Have you read the Contributing Guidelines on issues?

Yes

To Reproduce

1. Add some admonition classes to custom.css
2. Build with yarn start
3. Build with yarn build
4. Compare

Expected behavior

I should get the same visual output.

Actual Behavior

I do not get the same visual output.

Your Environment

• Docusaurus version used:

 "dependencies": {
    "@docusaurus/core": "2.0.0-alpha.70",
    "@docusaurus/preset-classic": "2.0.0-alpha.70",
    "@docusaurus/theme-search-algolia": "^2.0.0-alpha.70",
    "@mdx-js/react": "^1.6.21",
    "antd": "^4.9.4",
    "clsx": "^1.1.1",
    "core-js": "^3.8.1",
    "docusaurus-plugin-sass": "^0.1.11",
    "mobx": "^6.0.4",
    "react": "^17.0.1",
    "react-dom": "^17.0.1",
    "redoc": "^2.0.0-rc.45",
    "redocusaurus": "^0.2.2",
    "styled-components": "^5.2.1"
  },

• Environment name and version: Node v15.3.0. FF 85.0.2. Chrome 88.0.4324.150
• Operating system and version:MacOs 10.15.7

Reproducible Demo

See codesandbox but obviously that's not going to help build the packaged app.