One thing that makes style sheets as external documents acceptable (or more
nearly OK) in SoftQuad Panorama is that we have (in SGML) the concept of
`classes of document', all sharing the same DTD... and so a potentially
large number of documents can share a single style sheet.
The additional flexibilty, and the extra control that the author/publisher
gets over the appearance of the document seems well worth a small amount of
extra complexity in the browser.
It's interesting that style sheets can take attribute values into account,
for example to say
when the attribute LARGE is set on an Emphasis element,
double the text size
which allows the semantics of attributes to be somewhat decoupled from
the implementation in the browser, without any loss of specification.
Lee