Chrome添加标签（＃shadow-root（open））

Question

I have a div with some simple text inside, but whenever i apply the class "sidebar-ad" or "sidebar-advertisement", i get the following output:

I have searched my directory for "sidebar-ad" with Windows Grep, and I am not using this selector in my css, or in any js. Currently i'm just using a different selector ("sidebar-ads"), but what exactly is happening here? I tested using this same class on another project which is on another server and i had the same thing happen. What is this [hidden] tag that's being added? http://prntscr.com/cy5861

Sorry for the stupid question, but this is baffling me.

Thanks.

Edit, i tested with Edge and this isn't happening there. What is Chrome doing?

Edit, it's also happening with "sidebar-ads", so i'm now using "ad" lol

Answer 1

This is the Adblock extension modifying the HTML so your ads doesn't display.

If you disable it on this page, you will not see this css class anymore.