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  • Rachel Krupnick thinks this is interesting:

This is the most basic font declaration you can have:

font: <font-size> <font-family>;

Of course, you'd replace those bracketed terms with actual values, like so:

font: 100% sans-serif;

The point is that you must include both values, and they must be in that order—size, then family. Reverse them, or leave one out, and any modern browser will just ignore the declaration outright.