How to change the design of a site built on Opencart?

Question

css

Hello, I will mention in advance, I am new to this business, which is why I am asking the question here. How can I change (remake) the design of the main block (container or content, I don’t know how to do it right, shorter than the main block where all the information is)? for example, like here zadornov.net - the main block is beautifully designed. I know that you can install a template on the site, in connection with this, I have more questions: will the structure of the site change in this case (structure - in the sense of whether the menu bars will move out? Etc.)? Or just div blocks? do i need to add something to the css? Will the compatibility of modules in Opencarte be lost with the new design?
PS It is more convenient for me to do everything by hand and not to take templates, is it even possible? thanks in advance!!!

Answer 1

The question is easy to google.
here, for example:
asterial.ru/saytostroenie/sozdanie-shablona-dlya-o...
or here:
forum.opencart-russia.ru/threads/rukovodstvo-dizaj...

Answer 2

If you are comfortable with doing everything by hand, then take Firebug (or another debugger) and fix the display of blocks, starting from the general and moving to the specific, changing the CSS in the debugger and copying the rules into style files.

Answer 3

Have you read the documentation?