The following testcase works fine in Mozilla 20030220. It is broken in Phoenix 20030223 (hope it is broken in Mozilla too). What I expect is the second, .., nth lines to be aligned with the first character of the first line thus the margin-left: -1.4ex which represents the width of the :before.
*** Bug 194853 has been marked as a duplicate of this bug. ***
But 'margin' doesn't apply to :first-line according to the spec. See bug 103189.
Verified invalid. Sounds like what you _really_ want is a negative text-indent...