Google 公共库及字体等前端公共库 CDN 服务

css.loli.net 推荐

> https://css.loli.net/
```
https://ajax.loli.net      https://ajax.google.net/
https://fonts.loli.net     https://fonts.google.net
```
中科大

> https://lug.ustc.edu.cn/wiki/start
```
fonts.gstatic.com       fonts-gstatic.proxy.ustclug.org
fonts.googleapis.com    fonts.proxy.ustclug.org
ajax.googleapis.com     ajax.proxy.ustclug.org
```