I’m trying to adapt the one page demo to my needs, and in one module I have a fair bit of text. With the window about 960px it is fine; text is ranged left as I want. With a window smaller than 960px, text jumps to centred. I’m having trouble finding where to set this.
Do you mean that the sidebar gets moved when viewport is below 960px? This is a common design pattern for modern sites to achieve usability for mobile devices, as shifting the sidebar to the bottom of the page allows for easier focus on content before navigation. If you do not want this to occur, you can fix it by disabling the relevant CSS media queries in template.css and nucleus.css, specifically into something like this:
You’ll need to find the references and change them (I just commented them out with developer tools and copied the resulting css), or add them into custom.css with overrides.
Website looks good here, no noticable difference between aboven/below 960px except some responsive design changes. You can always just select the main content div in firebug, resize the window and see if any off the CSS properties get overwritten. Sounds like there might be a mediaquery defining text-align: center below 960px. Although for me it all remains aligned left regardless of the viewport size.