I found the solution.
in qa-styles.css:
Main area width:
.qa-main {
padding-left: 10px;
float: left;
width: 708px; //Change 708 to 710
margin: 10px 0 24px;
clear: left;
overflow: hidden;
}
Sidebar width:
.qa-sidepanel {
float: right;
width: 240px; //Change 240 to 238
padding: 10px;
min-height: 80px;
}