i think your version will break a bunch of common uses of `margin-{left,right}`; e.g. indenting like blockquote { margin-left: 15px; /* ... */ } w

i think your version will break a bunch of common uses of `margin-{left,right}`; e.g. indenting like blockquote { margin-left: 15px; /* ... */ } won't work properly (it'll go all the way to the left). i haven't checked, but i think that in the grid version, you'd get an indent as expected. and i think that's the grid version's main advantage – it doesn't "use up" `margin` and `max-width`, so you're free to use them to style stuff that appears in the body. feels a bit more composable, though at the cost of also feeling massively overcomplicated :/