I am sure the answer to this is trivial but I am stumped.

I am following an exercise in Marc Campbell'a book DW8 Design and Construction.

On page 150 he says how to define styles for specific elements.
I have set a 3-col layout with a floating centre col. and created a tempplate. I want to add some padding. Following Marc's book in the template doc window I click inside the main content area (center) go to the tag selector and select the div tag. In the CSS styles panel I click new rule button. Go to the advanced button and enter div.content (say) I then put some values in, for example, the box section of the CSS rule definition dialogue eg padding = 20px. Click OK, then save file go back to template document and apply the new rule by selecting the name of the rule from the property inspector.

I then update my files - the only problem is that nothing has changed I have tried repeating this a dozen times, anyone got any ideas. Think my brain has evaporated or something! No padding!!!!

I can get it to work by selecting the <p> tag and typing in some changes but for layout elements always the same result.

Many thanks