header{ position:absolute; z-index:3; left:0; top:0;}
header > a > span{ color:#fff; }
section > div.main1{ width:100%; height:200px; background-position:center center; background-size:auto 100%;}
section > div.main2{ width:90%; display:inline-block; margin-left:5%; margin-top:4em; margin-bottom:4em;}