body {width: 100vw;height: 100vh;
   
  margin: 0 auto;
}
* {
  font-family: "verdana";
  padding:0px ;
  margin:0px ;
}
header {width: 100%;
  height: 20%;
  position: relative;
  background-color:#66FF99
}

nav {
  width: 30%;
  height: 70%;
  float: left;
  position: relative;
  background-image:url(im3.jpg);
}

section { width:60%;
  height:70%;
  float:left;
  
}


footer { width: 100%;
  height: 10%;
  float: left;
  position: relative;
  background-color:#66FF99
}
aside{width: 10%;
  height: 70%;
  float:right;
}
iframe {
  width: 100%;height: 100%;

}
header h1 {
  float: left;
  font-size: 3rem;
  font-weight: bold;
  font-style: italic;
  width: 100%;
  text-align: center;
  color: goldenrod;
  text-transform: uppercase;
  text-shadow: 5px 5px silver;
  position: absolute;
  top: 50%;
  transform:translateY(-50%);
}

footer p{
  position:center;
  position: relative;
  top: 50%;
  text-align: center;
  transform:translateY(-50%);
  text-decoration: underline green; 
  background:linear-gradient(pink, yellow );
   
}
.fond{
  background-color:greenyellow;
}
a:link {
  color: red;
}
a:visited {
  color: green;
}