.botaotopo {
display:scroll;
position:fixed;
bottom:2px;
right:2px;
}

.backtotop, 
.backtotop::after, 
.backtotop::before,
.backtotop .backtotop-morph
{
    transition: all 250ms ease-in-out 0s;
}

.backtotop {
    border: 0px dotted white;
    width: 50px;
    height: 50px;
    right: 25px;
    bottom: 20px;
    position: fixed;

    cursor: pointer;
    transform: rotate(0deg);
    transform-origin: center center 0;
    z-index: 1000;
}
.backtotop::before {
    width: 18px;
    height: 4px;
    left: 6px;
    top: 56%;
    position: absolute;

    background-color: white;
    content: "";
    transform: rotate(-45deg) translateY(-50%);
    transform-origin: center top 0;
}
.backtotop::after {
    width: 25px;
    height: 4px;
    right: 5px;
    top: 50%;
    position: absolute;

    background-color: white;
    content: "";
    transform: rotate(45deg) translateY(-50%);
    transform-origin: center top 0;
}

/*Hover*/
.backtotop .backtotop-morph {
    background-color: white;
    
    width: 15px;
    height: 4px;
    left: 100%;
    top: 45%;
    position: absolute;

    opacity: 0;
    margin-bottom: -20px;
    transform: translate(-50%);
}
.backtotop .backtotop-morph::before {
    width: 0;
    height: 0;
    left: -7px;
    top: -4px;
    position: absolute;

    border-color: transparent white transparent transparent;
    border-style: solid;
    border-width: 6px 10px 6px 0;
    content: "";
}
.backtotop:hover {
    transform: rotate(90deg);
}
.backtotop:hover .backtotop-morph {
    left: 40%;
    opacity: 1;
}
.backtotop:hover::before {
    width: 30px;
    left: 10px;
    top: 30%;

    background-color: white;
    transform: rotate(0deg) translateY(-8px);
}
.backtotop:hover::after {
    width: 30px;
    right: 10px;
    top: 60%;

    background-color: white;
    transform: rotate(0deg) translateY(8px);
}