Weird! Using the Darie/Barnett book, everything good apart from one css rule not rendering. The weird thing is, all the other rules in that particular style definition do render correctly! The instance is on p.456 of the book (3rd edn, 2008) for the .gridheader class. Colour and font-weight are OK, but the text is still centred, not left-aligned. Here’s a copy of the style definition:
.gridheader
{text-align:left; background-color: #ADDE86;font-weight: bold;}