Remove featured image from top of post page

I like Reddle but I’d like to remove the featured image from the top of individual post pages. Which bit of CSS should I take out for that?

The site is https://www.planestrainsplantagenets.com/.

I’d also like to remove the black bars from around featured images on the main page when they’re too small – should I open another thread for that issue?

[Moderator note: Please ensure the website URL is valid]