How do I log out of the page?

Do you want to log out of the site completely? Most stay logged in so when they return they don't have to re-log in each time.
Your log out option is located to the upper right in the menu bar, by your profile (the little person) icon, it has a little drop down menu next to it.

@Jumper2 , are you leaving us?

I'm not leaving the site, I just want to log out of it on my phone. I can't find the place to log out.

On the phone, on the upper right is a three bar block. Click that and it gives you a drop down menu. Click the little arrow next to the profile 'person' and it gives you another drop down menu which has the log out option.
I had to go look on mine because I never log out on my phone either.