Q:

CMS existing HTML5/CSS3 website

I build HTML5/CSS3 websites that are cross-browser compliant and responsive. My clients want the ability to edit text areas and upload new stories into the news section and images to the photo gallery. What is my best option to continue building (clean, SEO friendly) websites while giving my clients the option to update the website themselves?
I have looked into the likes of a CMS like joomla and drupal and they seem heavily dependent on templates which scares me. Is it just a case of pasting my php-includes and css files into system that builds my unique 'template'? Other CMS options; cushycms and pagelime seem more along the lines of what I'm looking for but appear to edit existing text only?
In a nutshell; I want to keep my existing designs and simply make them editable.

A:

Sorry for the blatant self-promotion, but feel I have to chime in.
I'm the CEO of Webpop, a fully hosted CMS that's made with frontend developers and web designers in mind. 
We built Webpop exactly for solving this problem and have done a lot of work on making sure that you can keep your HTML/CSS and javascript exactly as it appears in your static mockup when building a site with Webpop.
We have two completely separate UIs, one for you, where we've done our best to make it as easy as we can to let you work directly with the HTML, CSS and javascript. And one for your clients, that's just a simple on-site editor where they can update the part of the site that's dynamic content.

