border radius on right only

Thanks for the great ticker. Very neat. I have had a ticker working across the foot of the page for a while.

I have just put another ticker at the top, limited to only a third of the page (on a desktop). Because of the theme, I have needed to put a colour backing on this one. However, the custom css doesn’t seem to work (or I am not using it properly), so I put the backing colour onto a span that encompasses the ticker (all in a div to limit it).

This is now showing up that the ticker has rounded edges – but only on the right! It wouldn’t be so bad if it was both ends. Inspecting the generated code, this is what it being put out:
<div class="spt-box" style="background-color: inherit;overflow: hidden;border-top-right-radius: 5px;border-bottom-right-radius: 5px;">...</div>
There seems no good way to change these radius settings.

In the Custom CSS Code, I have tried
.spt-box="border-top-right-radius: 2px;border-bottom-right-radius: 2px;border-top-left-radius: 2px;border-bottom-left-radius: 2px;"
and
"border-top-right-radius: 2px;border-bottom-right-radius: 2px;border-top-left-radius: 2px;border-bottom-left-radius: 2px;"
and
border-top-right-radius: 2px;border-bottom-right-radius: 2px;border-top-left-radius: 2px;border-bottom-left-radius: 2px;
but there’s no change to the generated code.

Any help on getting the Custom CSS Code to work, or on removing the right-hand only radii would be appreciated.

The page I need help with: [log in to see the link]