.anniu{
    background-color: green;
    color: #fff;
    padding: 10px 20px;
    text-decoration: none;
    display: inline-block;
    text-align: center;
    border-radius: 10px;
    transition-duration: 0.5s;
}
.anniu:hover{
    background-image: linear-gradient(to bottom right, green,greenyellow);
    padding: 15px 25px;
    box-shadow: 0 12px 16px 0 rgba(0,0,0,0.24), 0 17px 50px 0 rgba(0,0,0,0.19);
}