前端网站收集

bootstrap：

bootstrap中文网

http://getbootstrap.com/docs/4.1/getting-started/introduction/

菜鸟教程

https://www.w3cschool.cn/bootstrap/

1. 表单验证

https://www.cnblogs.com/landeanfen/p/5035608.html

2. 文件上传

https://www.cnblogs.com/landeanfen/p/5007400.html

CSS

css菜鸟教程

https://www.w3cplus.com/css3/how-to-use-css3-calc-function.html

http://www.divcss5.com/html/h121.shtml

Less

http://lesscss.org/#using-less

https://www.cnblogs.com/landeanfen/p/6047031.html

echarts

https://www.w3cschool.cn/echarts_tutorial/echarts_tutorial-mec528xa.html

city-picker

https://github.com/tshi0912/city-picker/blob/master/README.md

SVG

http://www.runoob.com/svg/svg-tutorial.html