.important  {
    font-family: Source Sans Pro;
    background: linear-gradient(45deg, #bcd7e1, #c7dbf0);
    color: #333333;
    padding: 50px 30px;
    border-radius: 8px;
}

.preuve  {
    font-family: Source Sans Pro;
    background: linear-gradient(45deg, #bcd7e1, #c7dbf0);
    color: #333333;
    padding: 50px 30px;
    border-radius: 8px;
}

.box {
  float: left;
  width: 150px;
  height: 190px;
  margin-right: 10px;
}