How to ajust left or right module

I thought that it would be possible to ajust the left or right module width within the template settings but i cannot find the settings anywhere. I want to size the mp_right module to about 200 px and the content part to 760 px. How is that possible ? (s. screenshot)
Thanks and br
Kiesel

You can roughly set width in layout designer in template options but unit is 1/12 of total template width. You can add explicit definition in bottom of layout.css:

.mp_right{
width:200px;
}