I've defined two Web Part Zones in the page layout, with nothing between them.
<WebPartPages:WebPartZone runat="server" Title="Zone 1" ID="Zone1" Orientation="Horizontal"><ZoneTemplate></ZoneTemplate></WebPartPages:WebPartZone>
<WebPartPages:WebPartZone runat="server" Title="Zone 2" ID="Zone2" Orientation="Horizontal"><ZoneTemplate></ZoneTemplate></WebPartPages:WebPartZone>
I've placed a CEWP in each zone. Once the page is out of edit mode, it renders like this:
How can I reduce the vertical spacing highlighted by the orange arrows?