How to make all landscape images full width by default

Currently none of the images in posts and pages display full width. I wish to display all landscape oriented images full-width by default when a new post is published. I still want to control image size for portrait oriented images.

Hello there,

I hope you are doing well today.

If you are referring to the parallax images they should be full width by default.
Could you please provide a link to your website so that I can inspect it?

Best Regards,

Sorry, I mean the post images. url:

I want the post images to expand full-width of browser.