Ask HN: April 21 Google Mobile Update?

How many of you are modifying your websites so that they pass Google's mobile friendly test? Yes, I know that ideally all websites should be responsive prior to this, but I also know there are many apps / websites that are not and have inner pages that are not responsive.

I also noticed that HN fails this test and has a poor mobile experience in general. Are there any plans to modify the CSS so that it has a better experience on smaller devices?

Edit: references

Announcement: https://plus.google.com/+GoogleWebmasters/posts/BASN3qVNMKV

Mobile testing tool: https://www.google.com/webmasters/tools/mobile-friendly/