I have been beating my brain about this one and just can't figure it out!

I'm trying to hid the for sale and feed columns for horses and dogs.

I have used a skeleton from Riley to figure out a lot of the coding, and it works fine on my main account, https://horsephenomena.com/home.php?id=4407 but it doesn't work on this one. Even copying and pasting the code it doesn't work. 

Any ideas as to why? Especially with it being a literal copy and paste?

I don't know much about coding.

But my first guess would be that each divider has it's own code identifier number, so if you copy and paste from a different account, you would still need to change it so your layout knows which divider you're trying to close/hide.

First thing first, I think having the plain text in the declaration part of the coding can throw things off - you should make sure they're set as notes so the browser doesn't get confused (because computers are stupid lol). You can set notes by using /* note here */
Like when you write down what each child element applies to, it should be th:nth-child(2) { /* Name Column Header */}

Second, any codes you apply to the dividers specifically won't work unless you have Use Dividers: Yes selected on your Edit Profile page ^^ Took me a stupid long time to figure that one out and I still forget it sometimes when I code on a new account :P

Wow! I can't believe it was just saying yes use the dividers. *facepalm* 

here I was thinking I wasn't coding right hahahaha

Thank you Mango!