.btn_enviar {
    text-decoration: none;
    color: #fff;
    font-size: 18px;
    font-weight: 400;
    display: inline-block;
    padding: 8px 20px;
    border-radius: 10px;
    margin-right: 20px;
    background: #1e1d4b;
    transition: all linear .5s;
    -webkit-transition: .5s;
    -moz-transition: .5s;
    -o-transition: .5s;
    -ms-transition: .5s;
    width: 100%;
}