border-image: -webkit-linear-gradient(to right,#d9762e, #eba254) 20 20;
border-image: -moz-linear-gradient(to right,#d9762e, #eba254) 20 20;
border-image: -o-linear-gradient(to right,#d9762e, #eba254) 20 20;
border-image: linear-gradient(to right,#d9762e, #eba254) 20 20;
原文：https://www.cnblogs.com/heartY/p/15137886.html