I'll answer my own question about floating a vertical format logo in the top-left corner of the page, in case anyone wants to do this. It turned out to be easy. :laugh: Remember, I'm using the Sage template; I've no idea if this would work in other templates.
First, replace the Zen logo with your own, in the usual place: includes/languages/english/header.php (Or in your override folder.)
In the style sheet give logo a style like this (adjust the px to suit)...
#logo {
position: absolute;
top: 10px;
left: 10px;
}
The "position: absolute" takes it out of the flow, so everything else on the page will ignore it.
In the style sheet give a left margin to whatever is in the header other than the logo -- in my case that was tagline and navMainWrapper -- to push them over to the right to avoid your logo.
You may or may not want to set a height on the header. I didn't since there's only text up there now that the logo is out of the flow.
You'll need a top-margin on the top-most element in your left column to push it down below the logo. In my case the cart summary sidebox is active and is first, so I put a large top-margin on its header, like so...
#cartsummaryHeading {
margin-top: 200px;
}
Add chocolate sauce to taste and serve over ice-cream! :P
Rob
Breakfast: the most important donut of the day.