.header {
    padding-top: 80px;
    min-height: 200px;
    background-color: white;
    display: flex;
    flex-direction: column;
    align-items: center;
    background-image: url(/ejercicio4files/html5.png);
    background-repeat: no-repeat;
    background-size: contain;
    background-position: center;
	margin: 15px;
	box-shadow: 2px 7px 10px 0px #888888;
}

footer {
   display: block;
   min-height: 100px;
   background:lightgrey;
   text-align:center;
   padding-top:80px;
   
   }
   
.section1 {
	display: flex;
	display: -webkit-flex;
	flex-direction:column;
	background-color:white;	
	margin:15px;
	padding-top:10px;
	padding-left:30px;
	padding-right:30px;
	text-align:justify;
	box-shadow: 2px 7px 10px 0px #888888;
}

.sectionreturn {
	display: flex;
	display: -webkit-flex;
	flex-direction:row;
	background-color:white;	
	margin:15px;
	padding-left:23px;
	padding-right:30px;
	box-shadow: 2px 7px 10px 0px #888888;
	background-image: url(/ejercicio4files/leftarrow.png);
    background-repeat: no-repeat;
    background-size: contain;
    background-position: left;al
}

.textovolver {
  padding-top: 10px;
  padding-bottom: 10px;
  margin-left:30px;
  font-size: 16px;
  background-color: transparent;
}


body{
  background-color: lightgrey;
  font-family: Verdana;
  font-size:12px;
}

a{
  text-decoration:none;
}


a:hover{
 background-color:blue;  
}