Conditional Formatting with Cards to Make a Heatmap

I have a physical seating chart of computers and I am logging the seats that are used the most. I have come up short of standard heatmaps and other map visuals. So, I created the layout with Cards and I applied a conditional format to them on the number of hours they were used. Shown below on the left is the layout with formatting applied and on the right is the table of values also with conditional formatting.

The problem I am having is that when applying conditional formatting to the cards, I am forced to enter a static value for High/Med/Low unlike the table of values. Is there a way to make the cards have a dynamic formatting as the numbers increase?

(Formatting)

Thanks!