Christmas Mode is a Gwern.net easter egg theme: when visiting this test page, or for web browsers with an English language locale which visit Gwern.net on Christmas (defined as 24 December after 6PM local time, or on 25 December all day), Christmas mode will be automatically activated in both dark & light mode. (Enable side-wite in browser console: toggleSpecialOccasionTest("christmas", true); & reload.)

Christmas Mode currently consists of randomized Christmas dropcap logos (available selection: dark mode n = 5, light mode n = 6), green outlining on block elements & links, alternating red/green list markers, and rubricated dropcaps.