body {
  display:flex;
  margin:0 auto;
  justify-content:center;
  background-image:url('background.gif');
}
.header, .nav, .content {
  margin:auto;
  width:850px;
}
a:hover {
  letter-spacing: 5px;
}
a {
  color:red;
}
.center {
  text-align:center;
}
.container{
  background-color:black;
  display:flex;
  flex-direction:column;
  width:850px;
}
.header {
  background-color:green;
  flex-grow:2;
  height:200px;
  font-size:170px;
}
.nav {
  background-color:orange;
  height:100px;
  display:flex;
  flex-direction:row;
}
.navlink {
  background-color:blue;
  flex-grow:1;
  font-size:40px;
  color:red;
  margin:auto;
  border:1px black solid;  
  display:flex;
  justify-content: center;
  align-items: center;
}
.content {
  background-color:pink;
  flex-grow:10;
  display:flex;
  box-sizing:border-box;
  height:1000px;
}
.leftbar {
  order:1;
  background-color:yellow;
  flex-grow:1;
  padding:10px;
}
.main {
  order:2;
  flex-grow:5;
  background-color:red;
  padding:10px;
}
.rightbar {
  order:3;
  background-color:yellow;
  flex-grow:1;
  padding:10px;
}