body {
  font-family: Arial, sans-serif;
  background-color: #66c6e39e;
  margin-left: 15%;
  margin-right: 15%; 
}

h1,
h2 {
  font-family: Georgia, serif;
}
  
h1 {
  text-align: center;
  color: #2d4000;
}

h2 {
  margin-top: 30px;
  color: rgb(116, 34, 194);
}
  

#source {
  font-style:  italic;
}
#cours{
  color:#3a4ab0;
  
}
#p {
  text-align: justify;
} 
 
#présentation{}