body {
    font-size: 14px;
    background: lightgrey;
}

.cadre {
    max-width: 30em;
    margin: auto;
    padding: 5px;
    border: 2px solid grey;
    border-radius: 10px;
    background: white;
}

@media (max-device-width: 600px) {
    .cadre {
	max-width: 100%;
    }
}

img.coin {
    float: right;
    margin: 3px;
    width: 7em;
}