QUOTE (DonH @ Apr 9 2012, 06:37 PM)
Which version do you have and how familiar are you with HTML and CSS? What is it you would like to change more often?
Earlier versions used tables for layout, but then used some CSS for some minor styling. Later versions use CSS for the majority of layout tasks as well as more extensive styling. The latest version has a built in CSS editor that allows you to make CSS edits while in a WYSIWYG view.
It is no problem to add style sheets to your existing store, nor is it a problem to use existing elements in the php pages as selectors or to add additional divs for layout or styling.
Yes this is really very nice Answer but in my point of if you want to change you can change it not a big issue.