Why does bootstrap add an extra horizontal line?

Why does bootstrap add an extra horizontal line?
0

#1

http://codepen.io/juanmndz/full/ygdzMg/ Whenever, I switched to mobile I get this line near the bottommy horizontal element that I did. It looks like every .container-fluid a horizontal line is added but don’t know why. So it would show as two lines picture here:


Any help explaining why this is happening and how to fix this to just show one white horizontal line would greatly appreciated.
Note: The problem seems to be showing just for mobile.


#2

because, at the bottom of every paragraph you have this <hr/> tag.

https://www.w3schools.com/tags/tag_hr.asp


#3

It’s actually very strange that you can’t see it on your non-mobile device. I can see it on my desktop. The <hr> tag adds a line. That’s what it does.