.conteneur{
  width: 80%;
  border: 1px solid black;
  background-color: #0AF;
  margin: 50px auto;
  box-sizing: border-box;
  position: relative;
}
.conteneur::after{
  display: table;
  content: "";
  clear: both;
}

#p1{
  display: none;
  position: absolute;
  left: 100px;
  float: left; 
}

#p2{
  display: inline-block;
  position: absolute;
  right: 50px;
  float: left; 
}
#p3{
  display: inline-block;
  position: relative;
  right: 50px;
  float: left; 
}
#p4{
  display: inline-block;
  position: relative;
  right: 50px;
}