#ButtonSociete {
width:                 100px;
margin-right: 50px;
}

#ButtonContact{
width:                 100px;

}

#ButtonProject{
width:                 100px;
margin-right: 50px;
}

#ButtonDocuments{
width:                 100px;
margin-right: 50px;
}

.VideoLinks a
{
float: left;
width:33%;
text-align:center;
margin-bottom : 40px;
margin-top : 20px;
}