给图片加上某种颜色的蒙版

.welcome-hero{ display: flex; align-items: center; justify-content: center; position:relative; background:url(../images/about/welcome-banner.jpg)no-repeat;#图片 background-size:cover; background-position: center; height:890px; } .welcome-hero:before{ position:absolute; content: " "; top:0; left:0; background:rgba(31,44,108,.65);#添加上去的颜色 width:100%; height:100%; }