Unable to remove margin on my website

I was wondering if someone could help?

I want to remove the margin from left and right on this page – https://dandelituskertrails.com/

I tried inserting this in Additional CSS , but it doesn’t seem to help

.container[role=main] { margin-top: 0; }

#content, #main-wrapper { padding-bottom: 0; }

section.post-content { margin-bottom: 0; }

Sorry, if its a very basic question as i’m a noob here.