  <style type='text/css'>
* {box-sizing: border-box;}
body {
margin: 0;
font-family: Arial;
}
.header {
overflow: hidden;
background-color: green;
padding: 20px 10px;
}
.header a {
float: left;
color: black;
text-align: center;
padding: 12px;
text-decoration: none;
font-size: 15px;
line-height: 25px;
border-radius: 5px;
}
.headera.logo {
font-size: 30px;
font-weight: bold;
}
.header a:hover {
background-color: grey;
color: black;
}
.headera.active {
background-color: orange;
color: white;
}
.header-right {
float: right;
}
@media screen and (max-width: 500px) {
.header a {
float: none;
display: block;
text-align: left;
}
.header-right {
float: none;
}
}
content {
  padding: 20px;
  background: #F3F6F7;
  overflow:hidden;
  }
.col {
  background:#eee;
  float:left;
  width:22%;
  margin-right: 4%;
  }
.col-4 {margin-right:0;}

    </style>