On retina screens CSS pixels don’t match device (physical) pixels. A device pixel ratio of 2 means one CSS pixel equals two device pixels. Here are few ways to draw a one-device-pixel border.
Gzip reduces the file size by compressing repeating sequences of bytes. The longer the sequences are, the better the compression rate. When all the bytes in a file are unique, the compressed file becomes even larger than the original.
When I develop this website locally I use n12v.dev virtual host. n12v.dev/index.html is just ~/Sites/n12v.com/public/index.html on the file system.
You can achieve this by either using Pow or /etc/hosts and Apache.
The easy way: Pow
curl get.pow.cx | sh
ln -s ~/Sites/n12v.com ~/.pow/n12v
Now n12v.dev serves index.html.
To serve a directory with a name different from “public”:
ln -s ~/Sites/usercss/www ~/.pow/usercss/public
None of the browsers handle CSS transition from/to auto values correctly.