Custom CSS not applying changes to Price Table.

Hi there,
The only thing i am having problems with is modifying the headings and content for the SiteOrigin price table. I have inspected the element and copied the css over to custom css and nothing changes.
I have used the following to change the color for the buttons text and still nothing. .

.so-widget-sow-price-table-atom-845f1fb8d6f5 .ow-pt-columns-atom .ow-pt-column .ow-pt-button a.ow-pt-link{
color: #000 !important;

}