How to deal with sub components and pictures in CSS

[Bigerfe]

//t.css

  .img{
          background: url('./img/c.png') left center no-repeat;
          width: 200px;
          height: 50px;
    } 
and
child component 
import  'a.css'
function Child(){

}

import Child from './child.js';
function Main(){
 return <Child />
}

[xblj]

need css-loader