.container {
position:relative; 
width:520px; 
height:360px; 
background:#CCFFCC; 
color:#000; 
margin:40px auto;
}

#atleft, #atright, #abright, #ableft{
position:absolute; 
width:20px; 
height:20px; 
color:#000;
background:#fff;
}

#atleft{
top:0; 
left:0;
}
#atright{
top:0; 
right:0;
}
#abright{
top:340px;
right:0;
}
#ableft{
top:340px;
left:0;
}

#qtleft, #qtright, #qbright,#qbleft{
position:absolute; 
font-size:150px; 
font-family: Arial; 
color:#CCFFCC; 
line-height:40px;
}

#qtleft{left:-8px;}
#qtright{left:-25px;}
#qbright{left:-25px; top:-17px;}
#qbleft{left:-8px; top:-17px;}