/*It is NOT necessary if you don't need our style.
You can create your own style*/
button#toTop{
    font-size: 1.6rem;
    color: #fff;
    cursor: pointer;
    height: 7rem;
    width: 7rem;
    background-color: #f09;
    background-image: linear-gradient(45deg, #3023AE 0%, #f09 100%);
    border: none;
    border-radius: 50% 50% 47% 53% / 77% 77% 23% 23%;
    box-shadow: 0 0 1rem 0 rgba(0,0,0,0.4);
    transition: all .5s ease; 
}
button#toTop:hover,
button#toTop:focus{
    border: none;
    outline: none;
    background-image: linear-gradient(45deg, #f09 0%, #3023AE 100%);
    box-shadow:  0 0 1rem 0 rgba(0,0,0,.4);
}