This space is the area where the category description text should be placed. As far as I can see, it is not visible in your store because there is some strange setting for the text color.
To have the categories descriptions displayed properly, please Ecwid control panel -> System Settings -> Design -> CSS Themes and click on "Duplicate" button there. Click "Save (Ctrl+S)". As a result you will get a theme that you can customize.
Then you should add the following rule to this new theme:
[code]
div.ecwid-productBrowser-categoryDescription {
color: black;
}
[code]
Click "Save (Ctrl+S)".
However, if you do not want to have the categories descriptions displayed at all, you can get rid of this empty space by adding the following CSS rule to your CSS theme (Ecwid control panel -> System Settings -> Design -> CSS Themes):
Code:
div.ecwid-productBrowser-categoryDescription {
display: none;
}
Click "Save (Ctrl+S)".