Testing Statement #5 Below of Section 5.5.5 of CSS1 Spec
5. Negative margin values are allowed, but there may be implementation-specific
limits.
PASS CRITERIA:
If statement #5 above is passed, this paragraph should have margins all
around of -2em (negative values).
The rule applied is "p {margin: -2em}".
All other properties of this page should be UA-default.