css文字渐变支持移动端

            > .van-icon::before {
              background: #e56300;
              background-image: linear-gradient(180deg, #ffbd96, #ff7f48);
              background-image: -moz-linear-gradient(180deg, #ffbd96, #ff7f48);
              background-image: -webkit-linear-gradient(180deg, #ffbd96, #ff7f48);
              background-image: -o-linear-gradient(180deg, #ffbd96, #ff7f48);
              background-clip: text;
              color: transparent;
            }