.diapo {
    width: 100%;
    overflow: hidden;
    margin-top: 50px;
}

.diapo ul {
    width: 400%;
    padding: 0;
    margin: 0;
    list-style: none;
}

.diapo li {
    float: left;
    width: 25%;
    text-align: center;
}

.imgDiapoHori {
    width: 100%;
}

.imgDiapoVert {
    height: 100%;
}