In .events-day-dayname I had to replace padding-bottom: .2em; with padding: 3px 0px;
I think it's awesome you've got everything in ems, but I couldn't get the dayname (letter, i.e. MTWTFSS) to align correctly on the y-axis with ems. For example, I tried padding-bottom: .6em; and it gave me the right font size, but the whole column is off on the y-axis by 1-2px.
This is really noticeable if you are scheduling the entire day. Since I don't like Evolution, I followed this guide to sync the calendar with my google account: [link]
The solution was simply to tone down the .app-well-app.running > .overview-icon background-color.
The default of rgba(255,255,255,0.7); was murder on the poor eyes and gave me a weak initial impression of the theme. I didn't think I was going to like it. Fortunately I was able to see past that and I am -very- glad I am sticking with Sud. Thank you for making this!
I have it set as follows and it solved the only perceivable issue: