[Affected versions]: Firefox 57.0a1 (2017-08-07) Firefox 56.0b1 (20170808030909) Firefox 55.0 (20170803103124) [Affected platforms]: Windows 10 64-bit Ubuntu 16.04 32-bit [Steps to reproduce]: 1.Launch Firefox with a clean profile. 2.Navigate to about:config and toggle the value of extensions.webextensions.remote to true. 3.Restart the browser. 4.Install https://addons.mozilla.org/ro/firefox/addon/adblock-for-firefox/ 5.Maximize the window. 5.Go to about:addons -> Extensions and open the AdBlock for Firefox details tab. [Expected Results]: There are no layout issues displayed while using AdBlock for Firefox webextension. [Actual Results]: - Twitter, Google+ and Facebook icons overlap the webextension preferences menu. - This issue is not reproducible with extensions.webextensions.remote set to false because the webextensions preferences are not displayed in add-on details tab. - See attached screenshot.