@bondcliff check that your browser window didn't get a bit too narrow. There's a fairly aggressive jump to low-width/mobile view in the current web client when the multi-column layout would get too narrow to work well.
@bondcliff (Personally I'd prefer that it did this more elegantly, stripping down to a two-column format or something as an intermediate step, but we'll see what happens long term with user styles and so on.)
@joshmillard That did it. Thanks, Hero!