HTML comments are not valid CSS. But no one told old IE and Navigator versions this important fact. It's for the best because they didn't really handle CSS all

HTML comments are not valid CSS. But no one told old IE and Navigator versions this important fact. It's for the best because they didn't really handle CSS all that well. If they encountered 2.x properties they'd often lose their shit and mess up the whole layout from spite. Eventually both caught on and interpreted everything in the <style> tag as the declared language and thus ignored the inappropriate HTML comment tags. At the same time their CSS handling also improved so they'd break less badly when actually encountering CSS.