CSS selectors not working

Hello,

I’ve noticed that the selectors .rt-tpg-container .layout1 .rt-holder .rt-detail .read-more and .rt-tpg-container .layout1 .rt-holder .rt-detail .post-meta do not have any effect on the respective page elements when I use them in the theme CSS; i.e. they do not override the default CSS from the plugin. I made sure to include !important. Does anyone know a solution to this?

Thank you! ?? Much appreciated.

Here is a link to the example:
https://www.degroenehuismus.nl/grid/

https://www.ads-software.com/plugins/the-post-grid/