这是代码。图层的颜色没有变化。那么,我该怎么办?


 < div style =“width:640px; height:480px; position:relative;”>
 < iframe src =“https://drive.google.com/file/d/0BxLbnVHP6GWpV2ZIZEc4SkNTOTQ/preview”width =“640”height =“480”frameborder =“0”scrolling =“no”seamless =“”> < / iframe中>
 < div style =“width:80px; height:80px; position:absolute; opacity:0; right:0px; top:0px; background-color:#FF0000;”> < / DIV>
< / DIV>
 代码>