/* ====================================
   CSS setup – ne rien modifier
   éditer plus bas
 * ==================================== */
body { margin: 0; padding: 0; border: 0; }
section { min-height: 100vh; }
div { background-color: lightgrey; 
        width:100%;
}
div:nth-of-type(5n+1) { background-color: #1abc9c; }
div:nth-of-type(5n+2) { background-color: #3498db; }
div:nth-of-type(5n+3) { background-color: #9b59b6; }
/*div:nth-of-type(5n+4) { background-color: #e67e22; }
*/div:nth-of-type(5n) { background-color: #e74c3c; }
span { background-color: rgba(255, 255, 255, .5); 
        border-radius: 50%; 
        display: block; 
        font-size: 48px; 
        height: auto; 
        line-height: 3em; 
        text-align: center; 
        width: 3em; }

/* ====================================
   éditer à partir d'ici
 * ==================================== */

section{
  display:flex;
/*  EX Flex Color 2 */
  flex-wrap:wrap;
}
section div{
  width:25%;
}

/*  EX Flex Color 3 */

section{
  display:flex;
  flex-wrap:wrap;
  width:95%;
  margin-left:auto;
  margin-right:auto;
  justify-content:space-around;
  align-items:center;
  align-content:center;
  border: 2px solid black;
}

  section div{
  height:500px;
  width:24%;
  margin-bottom:10px;
  margin-top:10px;
  display:flex;
  align-items:center;
  justify-content:center;
}