.row {
    text-align: center;
}
.action {
    cursor: pointer;
}
.action span {
    display: block;
    margin: auto;
    margin-bottom: 10px;
    width: 250px;
    font-size: 2em;
    border: 1px solid #ddd;
    border-radius: 5px;
    padding: 10px;
}
.action span:hover {
    background-color: #ddd;
}
#entree span:before {
    content: url('../img/entrance.png');
    display: block;
}
#sortie span:before {
    content: url('../img/exit.png');
    display: block;
}
#goback {
    cursor: pointer;
    font-weight: bold;
}