📅  最后修改于: 2022-03-11 14:47:26.102000             🧑  作者: Mango
.bordertest {
height:300px;
width:300px;
border-top:30px solid #c4268c;
background:#000;
position:relative;
margin:1em;
}
.bordertest:first-child:before {
content:'';
position:absolute;
width:100%;
height:30px;
background:linear-gradient(to left, #c4268c, #9a0b72);
top:-30px;
left:0;
}