/*  utilidades  */
div.contenedor {
    max-width: 625px;
    margin: 12px 0;
    text-align: center;
    overflow-x: hidden;
}

/*  canvas  */
#canvas {
    width: 400px;
    height: 150px;
}

canvas.pantalla-juego {
    border: 2px solid white;
}

@media only screen and (min-width: 400px) {
    #canvas {
        width: 500px;
        height: 270px;
    }

    h1 {
        font-size: 1.9em;
    }

}

@media only screen and (min-width: 783px) {
    #canvas {
        width: 700px;
        height: 300px;
    }

    h1 {
        font-size: 2em;
    }
}