Is there a way to hide this part of the dividers in CSS?

[contrapasso3]

What I’m trying to do

I want to hide the top part of the dividing lines so that the frame header is clean and solid.

Things I have tried

I’ve looked at and tinkered with the CSS from a couple of themes that manage a feature called Colorful Frame, but I can’t figure out how to get the CSS to work in my theme. I’ve tried changing the divider height as well with no luck. I used pixels; maybe that’s wrong. Not sure.

[woofy31]

This should do the trick:

.workspace-split.mod-left-split > .workspace-leaf-resize-handle, 
.workspace-split.mod-right-split > .workspace-leaf-resize-handle {
	top: var(--header-height);
}

Nice and clean:

Only downside is that you cannot resize the panes at the top where the splitters aren’t visible anymore.