can’t see text is a link

HI guys.

I have just built my website with wordpress.

I am having an issue where when I create a link to external website on either a post or page the colour does not change so its difficult to see thats its a link. The colour does change when you hover a mouse over it.

For example see the post
https://nisekochiropractic.com/2018/11/02/the-top-3-niseko-conditioning-exercises-your-not-doing/

There is a link
https://www.johnsonfitness.com/blog/single-leg-romanian-dead-lift-right-way/

Just above the video that does show up as link until you hover over it.

I am using a medicare theme with a child them. Im not sure where the best place to make some the changes are and what code I should put it. The theme does have CSS style sheet override so maybe I need to use that.

I would really value some assistance on
1. what code to use
1. Where to put the code

thanks so much. Sorry in advance for my lack of coding experience I have been way out of my depth with this but learning a lot along the way.

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