渐变色样式

只是样式：

.rainbow {
        width: 200px;
        height: 50px;
        background-image: linear-gradient(to right, #ff9569 0%, #e92758 100%);
    }
.azure {
        width: 200px;
        height: 50px;
        background-image: linear-gradient(-90deg, #29bdd9 0%, #276ace 100%);
    }