flexible th
HTML
<table id="table-parent" border="1">
<thead>
<th><div id="div-children"></div></th>
</thead>
<table>CSS
th {
width:300px;
}
#div-children {
height:200px;
width:100px;
border: 1px solid black;
background: blue;
top:50px;
left:50px;
position: absolute;
}