.center {
        display: block;
        margin-left: auto;
        margin-right: auto;
        width: 50%;
      }
    .absolute{
        margin-left: 300px;
    }
    @media(max-width:900px){
    .absolute{
    margin-left: 50px;
    }
    }
    .tarjeta{
    margin-left: 300px; 
    }

    @media(max-width:900px){
    .tarjeta{
    margin-left: 0px;
    }
    }
    .picture{
      height: 400px;
    }