Why doesn't the bottom work?

Question

https://code.sololearn.com/WVAco6M4It34/?ref=app

Answer 1

Because you have no element under the button.
And because you coded follow:
margin: auto;

Here you can see how works „bottom“:

https://code.sololearn.com/W6UGI71m226n/?ref=app

Answer 2

This is another example:

https://www.w3schools.com/CSSref/tryit.asp?filename=trycss_js_margin-bottom

https://www.w3schools.com/CSSref/tryit.asp?filename=trycss_play_margin-bottom

Answer 3

repeat question, and we've already answered this.

Answer 4

https://www.sololearn.com/Discuss/3032154/?ref=app

Answer 5

What do you mean by bottom? The button is working fine for me.