#pioche {
  float: left;
  width: 100%;
  height:44vw;
  margin-left: 0px;
  padding: 0px;
  border: 0px solid black;
  background-color: #eeeeee;
}

#case_ex6_1,#case_ex6_5,#case_ex6_9,#case_ex6_13 {
  float: left;
  width: 34%;
  height:35%;
  margin-left:11%;
  margin-top: 0px;
  margin-bottom:0px;
  padding-top:3%;
  padding-bottom:0%;
  background-image: url("../img/f-fd.svg");
  background-repeat: no-repeat;
  background-size: 100%;
}

#case_ex6_2,#case_ex6_6,#case_ex6_10,#case_ex6_14 {
  float: left;
  width: 38%;
  height: 37%;
  margin-top: 0px;
  margin-left: 2%;
  margin-right: 0px;
  padding: 0px;
  background-image: url("../img/g-fd.svg");
  background-repeat: no-repeat;
  background-size: 100%;
}

#case_ex6_3,#case_ex6_7,#case_ex6_11,#case_ex6_15{
  float: left;
 width: 70%;
  height:23%;
  margin-top: 0.5%;
  margin-bottom: 0.5%;
  margin-left: 14%;
  padding: 0px;
  background-image: url("../img/t-fd.svg");
  background-repeat: no-repeat;
  background-size: 100%;
}

#case_ex6_4,#case_ex6_8,#case_ex6_12,#case_ex6_16{
  float: left;
  width: 70%;
  height:23%;
  margin-top: 0.5%;
  margin-bottom: 0.5%;
  margin-left: 14%;
  padding: 0px;
  background-image: url("../img/s-fd.svg");
  background-repeat: no-repeat;
  background-size: 100%;
}

#div1_ex6 {
  float: left;
  width: 49%;
  height: 49%;
  margin-left: 0.3vw;
  margin-right: 0.1vw;
  margin-top: 0.2vw;
  margin-bottom: 0.3vw;
  color:#000000;
  text-align: right;
  background-color: #ffffff;
}

#div2_ex6 {
  float: left;
  width: 49%;
  height: 49%;
  margin-left: 0.2vw;
  margin-right: 0.1vw;
  margin-top: 0.2vw;
  margin-bottom: 0.3vw;
  color:#000000;
  text-align: right;
  background-color: #ffffff;
}

#div3_ex6 {
  float: left;
  width: 49%;
  height: 49%;
  margin-left: 0.3vw;
  margin-right: 0.1vw;
  margin-top: 0vw;
  margin-bottom: 0vw;
  color:#000000;
  text-align: right;
  background-color: #ffffff;
}

#div4_ex6 {
  float: left;
  width: 49%;
  height: 49%;
  margin-left: 0.2vw;
  margin-right: 0.1vw;
  margin-top: 0vw;
  margin-bottom: 0vw;
  color:#000000;
  text-align: right;
  background-color: #ffffff;
}

#nom_fonction1, #nom_fonction2, #nom_fonction3, #nom_fonction4{
 float: left;
 width: 95%;
 padding: 0px;
 margin-bottom: 1%;
 background-color: #FFFFFF;
 color:#FF0000;
 text-align: center;
 font-size:0.8em;
}

#f1,#f2,#f3,#f4{
 float: left;
 width: 45%;
 height:7%;
 padding-top: 0%;
 margin: 0.5%;
 background-color: #FFFFFF;
 text-align: center;
}