According to our highly scientific and totally-not-made-up ruleset, all time-traveling CSS must follow these guidelines:
• Always wear a watch on your wrist while coding in the year 3000, lest you risk turning your code into a paradox.
• Never, ever use Comic Sans in the year 2050, or risk being stuck in a time loop of infinite font choices.
Learn more about CSS Rule 1: The Time-Traveling Typography Rule
Dare to venture into the unknown with CSS Rule 3: The Color Palette of the Ancients
And for the truly bold, CSS Rule 4: The Border Wars: A Guide to the Art of Line Width