.btn_top_cont{
    position: fixed;
    bottom: 1rem;
    right: 1rem;
    width: 3rem;
    height: 3rem;
    z-index: -1;
    transition: transform .3s;
    &:hover {
        transform: translateY(-5px);
    }
}
.btn_top{
    width: 0rem;
    height: 0rem;
    /*-- color de boton subir --*/
    background-color: #2071b2;
    border-radius: 50%;
    cursor: pointer;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: -1;
    &:hover{
        background-color: rgba(32, 113, 178, .9);
    }
}
.btn_top i{
    position: absolute;
    font-size: 1.7rem;
    top: 48%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0);
    color: #fff;
    transition: .3s;
    margin: auto
}
.show{
    z-index: 100;
}
.show .btn_top{
    animation: uping .3s ease-in;
    width: 4rem;
    height: 4rem;
    z-index: 1000;
    
    
}
.show i{
    transform: translate(-50%, -50%) scale(1);
}

@keyframes uping {
    0%{
        width: 0;
        height: 0;
    }
    50%{
        width: 5rem;
        height: 5rem;
    }
    100%{
        width: 4rem;
        height: 4rem;
    }
}