Panel with label in it has unwanted border (?)


I have following problem. My panel shows a weird horizontal line below Persoonlijke informatie. The black vertical line you can ignore, that’s just bad cropping. Does anyone have an idea where this border/shading/? comes from?

I have a panel which is created through following code:
Panel infoPersonalHeader = new Panel();
infoPersonalHeader.setSizeUndefined(); // Shrink to fit content

I have a label which is created through following code:
final Label infoPersoonlijk = new Label(“Persoonlijke informatie”);

The infoHeader css is this:
color: #A9BE09;
margin-left: 15px;
font-family: Trebuchet MS;
font-size: 20px;
padding-left: 15px;
width: 730px;

I add the label to the panel through following code:

and add the panel to my layout:


in Valo (Vaadin 7.3+) all panels include a default border. You can remove it with a ValoTheme Constant.

Panel panel = new Panel();

It did the trick, thanks!