Bootstrap form-group and form-control

https://github.com/twbs/bootstrap/blob/21f3375f21e9a7a5155d0cd783fd2bc7aeee8485/scss/_forms.scss

https://github.com/twbs/bootstrap/tree/21f3375f21e9a7a5155d0cd783fd2bc7aeee8485/scss/forms

 

form-group定义在https://github.com/twbs/bootstrap/blob/21f3375f21e9a7a5155d0cd783fd2bc7aeee8485/scss/forms/_layout.scss

form-control定义在https://github.com/twbs/bootstrap/blob/21f3375f21e9a7a5155d0cd783fd2bc7aeee8485/scss/forms/_form-control.scss