Gamelast,
<!DOCTYPE html>
<html>
<head>
<title>Untitled</title>
<meta charset="utf-8">
<style type="text/css">
.dk_adpt_inner{
display:flex;
width:100%;
}
.dk_adpt_inner>div{
background:#FFD700;
height:200px;
border:2px solid #006400;
}
.dk_adpt_inner>.a_left,.dk_adpt_inner>.a_right{
flex:1;
}
.dk_adpt_inner>.a_center{
width:100px;
background:#32CD32;
}
</style>
</head>
<body>
<div class="dk_adpt_inner">
<div class="a_left"></div>
<div class="a_center"></div>
<div class="a_right"></div>
</div>
</body>
</html>