[css-fonts-4] Clarify that the angle must be the same sign as requested, #8914

Author: svgeesus

css-fonts-4/Overview.bs

@@ -1185,7 +1185,9 @@ Font style: the 'font-style!!property' property</h3>
 	both an oblique and an italic,
 	multiple oblique faces at various angles,
 	or various combinations thereof.
-	The font matching routine will select a font to use which is closest to the requested angle.
+	The font matching routine will select a font to use 
+	which is of the correct sign as the requested angle,
+	and (if there are multiple such faces) closest to the requested angle.
 	In general, for a requested angle greater or equal to 11deg,
 	larger angles are preferred;
 	otherwise, smaller angles are preferred.