h2 {text-align: center;}

header{height: 50px;width: 100%;}
header img{height: 40px;float: left;}
header div{float: right;}

nav{width: 100%}
nav>div {border-left: 1px solid grey ;min-width: 150px;}
nav div{float: left;width: calc(25% - 1px);}
nav .big{width: calc(50% - 1px);}
nav h2{font-size: 25px;min-height: 50px;}
nav img{width: 40px;float: left;max-width: 100%;padding-right: 10px;}
nav a{color: black;} nav a:hover{font-weight: bold;}
nav li{list-style-type: none;margin: 0 2px 30px -38px}
nav h3{clear: both;}