Can't change font size

I am using this widget on https://amy-and-duncan-are-getting-married.co.uk/rsvp/
I have changed the format to display in days and I have managed to change the font size of the title, however I want to change the font size of the countdown time as it’s small and not as clear to read, I’ve read up and I can’t seem to find whereabouts the css file is, I can right click and click on inspect element (Google Chrome) and add these 2 lines
padding-top: 10px;
font-size: 25px;

and can see the changes but I can’t find anywhere the css property
#shailan-countdown-2, .shailan-countdown-2.hasCountdown {

Any help would be grateful
Thanks Craig

https://www.ads-software.com/plugins/wordpress-countdown-widget/