新增: - backend/venv/ - Python 虚拟环境 - backend/start.sh - 启动脚本(使用虚拟环境) - backend/requirements.txt - 依赖列表 - .gitignore - 忽略虚拟环境和缓存文件 说明: - 每个项目使用独立虚拟环境 - 避免依赖冲突 - 启动脚本自动创建和激活虚拟环境
PostCSS Browser Comments 
PostCSS Browser Comments lets you keep only the CSS you need based on comments and your browserslist.
/**
* Prevent adjustments of font size after orientation changes in IE and iOS.
*/
html {
-ms-text-size-adjust: 100%;
-webkit-text-size-adjust: 100%;
}
The comment and rule above would be removed with the following browserslist:
last 2 chrome versions
The rule below would be more carefully altered:
/**
* 1. Add the correct box sizing in Firefox.
* 2. Show the overflow in Edge and IE.
*/
hr {
box-sizing: content-box; /* 1 */
height: 0; /* 1 */
overflow: visible; /* 2 */
}
/* with a `last 2 firefox versions` browserslist becomes */
/**
* 1. Add the correct box sizing in Firefox.
* 2. Show the overflow in Edge and IE.
*/
hr {
box-sizing: content-box; /* 1 */
height: 0; /* 1 */
}
PostCSS Browser Comments can remove rules based upon the comment above them, or it can remove declarations using numbered comments that reference the rule above them. In the later case, when all of the numbered comments are removed, then the entire rule and comment are also removed.
Usage
Add PostCSS Browser Comments to your project:
npm install postcss postcss-browser-comments --save-dev
Use PostCSS Browser Comments to process your CSS:
const postcssBrowserComments = require('postcss-browser-comments');
postcssBrowserComments.process(YOUR_CSS /*, processOptions, pluginOptions */);
Or use it as a PostCSS plugin:
const postcss = require('postcss');
const postcssBrowserComments = require('postcss-browser-comments');
postcss([
postcssBrowserComments(/* pluginOptions */)
]).process(YOUR_CSS /*, processOptions */);
PostCSS Browser Comments runs in all Node environments, with special instructions for:
| Node | PostCSS CLI | Webpack | Create React App | Gulp | Grunt |
|---|
Options
browsers
The browsers option overrides of the project’s browserslist.
postcssBrowserComments({
browsers: 'last 2 versions'
});