Issue 5135 - Reduce font size and padding on smaller screens on acceptableads.com

includes/tool-certification/summary.md

Index: includes/tool-certification/summary.md
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--- a/includes/tool-certification/summary.md
+++ b/includes/tool-certification/summary.md
@@ -11,9 +11,10 @@
 {{adblock-plus-getting-users-back[Acceptable Ads Tool paragraph 3] Adblock Plus has been getting these users back with the Acceptable Ads initiative. The secret of the initiative is trust: users don’t have to take part, but because it’s on their own terms, most do. And yet, after over five years of existence, it was still a labor-intensive process for publishers and advertisers to join.}}
 
 {{acceptabl-ads-tool-wins[Acceptable Ads Tool paragraph 4] Not anymore. The Acceptable Ads Certification Tool (AACT) is an open infrastructure that validates Acceptable Ads and facilitates them being served using tools common to the ad tech industry.}}
 
 ## {{easy-implementation[Easy Implementation Heading] Easy implementation optimized for your audience}}
 
 {{see-pre-approved-ads[Easy Implementation paragraph 1] You can use pre-approved ads from various demand channels, or you can use your own and let the AACT check them in real-time against the Acceptable Ads criteria. The implementation is simple, intuitive and includes a unique user feedback mechanism, which lets you optimize your ads for your specific user base.}}
 
-[{{sign-up-label[Sign Up button label] Sign Up}}](https://platform.acceptableads.me/signup){: .btn-primary .m-t-sm .m-b-xl target="blank" }
+[{{sign-up-label[Sign Up button label] Sign Up}}](https://platform.acceptableads.me/signup){: .btn-primary target="blank" }
+{: .btn-container }