divs created via Oxygen‘s Column element will have 20px padding by default on all the 4 sides.
Interestingly, these values appear as 0 at Advanced > Size & Spacing. But to actually set them to 0, you would need to enter 0 in the padding control fields.
This will work only with the ID selected but not a class (if there’s one set) because the class-attached CSS generates a less specific selector than what Oxygen includes out of the box – .ct-new-columns > .ct-div-block
.
If you want to set them to 0 globally, add the following in your CSS (Manage > Stylesheets):
.ct-new-columns > .ct-div-block {
padding: 0;
}
A better approach would be to selectively add a class of say, no-padding
to only those column elements that should not have padding (for the child divs) via the following CSS:
.ct-new-columns.no-padding > .ct-div-block {
padding: 0;
}