[SOLVED] Dumb Mistake: Layout wrong, menu not in banner row

I was putzing around with CSS and header.php and did something I couldn't trace back and now I've got my menu floating somewhere down the right-hand side of the page. It appears as if it's not in the banner div, even though it's nested under that in the generated code.

<div id="banner" class="row">
<div id="logo-area" class="col8">...</div>
<nav id="menu1-wrapper" class="menu-wrapper col4">...</nav>

Obviously, I'm giving 8 cols to the logo and 4 to the menu; I've tried 7 and 5 and so on, but still not getting anywhere. But it always adds up to 12 I know that.

In header.php, I thought I had restored everything back to the way it was meant to be. If I try to wrap the nav array in div tags then it disappears entirely...just not sure what I did that rendered this f'd up.

BTW, after this boneheaded mistake, I am installing MAMP and setting up a proper dev environment. Somebody could get hurt doing this stuff!

Thanks in advance...