.btn-circle.btn-xxl {
    width: 70px;
    height: 70px;
    padding: 10px 16px;
    border-radius: 35px;
    font-size: 24px;
    line-height: 1.33;
} 

.btn-circle.btn-xl {
    width: 40px;
    height: 40px;
    padding: 6px 0px;
    border-radius: 50px;
    font-size: 18px;
}

.btn-circle {
    width: 30px;
    height: 30px;
    padding: 6px 0px;
    border-radius: 15px;
    text-align: center;
    font-size: 12px;
    line-height: 1.42857;
}

.btn.estilo span {
    transition: .4s ease-in-out all;
    position: : absolute;
    left: 40%;
}

.btn.estilo .icono {
    display: flex;
    align-items: center;
    position: absolute;
    z-index: 2;
    left: -40px;
    transition: .3s ease-in-out all;
    opacity: 0;
}

.btn.estilo svg{
    color: #fff;
    width: 35px;
    height: 35px;
}

.btn.estilo:hover {
    background: #DC3545;
    color: #FFF;
}

.btn.estilo:hover .icono {
    left: calc(100% - 400px);
    opacity: 1;
}

.btn.estilo:hover span {
    left: 20px;
}