I was looking at the Webflow demo kit just to remind myself on how to do something.
When I look at the page LAYOUT > CENTERING (X AND Y)
The div block (class xy-container) is shown as 100& with a pink fill.
This occupies the whole of the screen real estate.
DEMO KIT SITE
When I copy the settings on my site, the Div Block is 1px high even at 100%.
Have I got a weird preference set on my site or something?