Why does the layer increase in width when I designate header tag?

[carlnelson]

Is this a CSS Style thing...or something simpler. When I designate text with a header tag in a narrow layer with colored background, save it and upload, the colored layer width has increased. How can I keep the width of the layer the same but designate the text as a header?

The width of the layer does not change in Dreamweaver - only after I upload to the server.

I'm a search engine specialist - not a web designer!

Carl Nelson