📜  css代码示例中的图像叠加

📅  最后修改于: 2022-03-11 14:47:57.479000             🧑  作者: Mango

代码示例2
footer#site-footer{  
  position:relative;
}

footer#site-footer:before {     /* use before property (pseudo-element)  */
    position: absolute;
    content: '';
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.3);
}