A bottle You're correct, that was the answer

What has a lock but no door?

A dance? Popping and Locking?

What has no box, key, or lid, yet a golden treasure is hidden within?

An egg. No, the answer was a keyboard, but good try

What gets wetter the more it dries?

A towel?

What has 13 hearts but no other organs?

A pack of cards! I think?

What can run but can't walk?

A river.

I'm a one-seeded fruit but your calender is full of me. What am I?

Dates! My sister figured this one out!

What do you call a three legged creature?

Tripedal.

What goes up and down but never left or right?

An Elevator? Tempature?

Here’s the worlds hardest riddle. don’t overthink it.

I turn polar bears white and I will make you cry. I make guys have to pee and girls comb their hair. I make celebrities look stupid and normal people look like celebrities. I turn your pancakes brown, and I make your champagne bubble. If you squeeze me, I’ll pop. If you’ll look at me, you’ll pop. Can you guess the riddle?

No, I can not guess the riddle.

Alright, this is a riddle I made myself. You willn't find the answer on google. Believe me, I tried. Okay, here it is:
A door can have 3 states. One is locked, the other is unlocked. What is the third?
And it's not open or closed. Open is unlocked, a closed door can be unlocked or locked.
All right, the answer is...
Useless. You get this state by taking the door of its doorframe. It is a door alone. It's not locked because... well, what would it lock against? It can't be unlocked because something has to be locked to turn unlocked. It's useless because you can't really use it for anything. (Except hitting annoying sisters.) It's simple logic, people. I think this is competing for the place of hardest riddle ever. I mean, even google didn't know!