.body
{
    width:100%;
    height:100%;
}

#tarjetaboot
{
    display: flex;
    justify-content: center;
    width: 70%;
    height: 50%;
    margin: 0 auto;
    margin-top:30px;
}
.card-body
{
    width: 50%;
    height: 50%;
}
.col-12
{
    margin-top:30px;
    margin-bottom:30px;
}
#signup
{
    width: 200px;
}

 @media screen and (max-width: 600px) {
     #tarjetaboot
{
    display: flex;
    justify-content: center;
    width: 90%;
    height: 50%;
    margin: 0 auto;
    margin-top:30px;
}
          }