I’m just getting to grips with CSS and minimal HTML markup, instead of
the cheap and dirty tables-as-layout method. Aside from an obsession
with standards and best practice (nothing wrong in that), using CSS as
the only means of controlling layout is now generally accepted as the
only way to go (look here)

In the early days of HTML sites tended to look pretty crude, and
didn’t use HTML for layout at all (except perhaps the hr tag and using
background images to make the text really hard to read). In fact, when
I started my own site in the pioneering days of 1995 it looked exactly
like a modern CSS site would look if you stripped away the CSS. ie.
pretty crap. But it did the job.

However, migrating to CSS might be lovely when you’re building simple
sites like this. But they can be a nightmare when you’re used to
building ‘stretchy’ ecommerce sites. I’ve tried doing exactly this
with a test site for a client, and it’s taken me a couple of days more
than it used to to cut up the designs and build the site. But once
it’s done, it’s done.

Why the hassle? Basically it’s good old cross-browser incompatibility.
Some of the neat CSS2-compliant tricks (min-width is a very good
example) you can use in Firefox just won’t work in IE. Even if
Microsoft were to sort out some of this, the legacy will continue to
bug developers for years to come until 90% of people in the world use
browsers that actually match the standards (by which time we’ll all be
using CSS3…)