Do you have a link? I can't always answer these questions without knowing what is creating the space. For example, in the default
vertical layout, there is a
<hr> (horizontal rule) which is basically creating the space. The "horizontal rule" can be disabled from your vertical layout settings, but then default margin is added instead, in which case you would need to add the following to
Settings > Custom > Custom CSS:
.layout-vertical .item {
margin-bottom: 5px !important;
}
The above would affect vertical layout on all pages. If you only want to affect the current page, instead add it into page settings > Page > Advanced > Page CSS. Also, keep in mind that margins are normally assigned adjust slightly on across different screen sizes, which will be ignored if you set it as per above.