Retina屏幕下的两倍图

原文地址

• css方案

  #element { background-image: url('hires.png'); }
  
  @media only screen and (min-device-pixel-ratio: 2) {
      #element { background-image: url('hires@2x.png'); }
  }
  
  @media only screen and (min-device-pixel-ratio: 3) {
      #element { background-image: url('hires@3x.png'); }
  }

• js

  retina.js