#conteneur{
	width:800px;
	margin:auto;
	padding:40px;
	background-color:white; 
	opacity : 0.8;
	}
#compte_a_rebours{ 
	font-size:30px; 
	text-decoration:underline;
	text-align:center;
	}	
#convertisseur{
	text-decoration:underline;
	font-size:15px;
	}
#rafa{
	text-decoration:underline;
	font-size:25px;
	}
	body {
  background: url("https://media.giphy.com/media/4H3Ii5eLChYul9p7NL/giphy.gif") no-repeat center fixed; 
  background-size: cover;
 }

#leafar{
	text-decoration:;
	font-size:25px;
	}
#coucou{
	text-decoration:underline;
	font-size:25px;
	text-align:center;
	}
#koala{
	text-decoration:underline;
	font-size:25px;
	text-align:center;
	color:red;
	}