Limits the maximal line-length ("paragraph width") of elements that are supposed to hold text directly in them. For better readability: unlimited paragraph width on large viewports is hell; too wide text columns on tiny viewports causes ugly horizontal scroll. Also, it tries to centre them.

It is said that optimal paragraph width is somewhere around 80 glyphs per line.
I am using "60ex" max-width for elements that mostly uses proportional font, and "80ex" for those commonly 'monospaced'. Tweak it yourself if you like ;)

This should not destroy any layout (it is not using any "!important"), but it does not mean it cannot cause any unwanted change.

Namely affecting these elements:
[p, h2-6, caption, th, lh, td (Yes, disputable. Remove if it makes troubles), li, dt, dd, address, blockquote; pre, xmp]

For more info see the source.

Feedback welcomed!