2
You can:
1) embed the style definitions as well as the id/style tags in the block html (block info below).
2) use existing, or create new styles in the *style sheet for your theme*, link to it, and code the tags in the block html.
3) create a new style sheet and link it to and code the tags in the block html.
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these are the 2 files that control the html output.
xhld0_block_rss.html - xhld/templates
xhld0_block.html - xhld/templates
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this file controls the output from the 2 files above
xhld0_block_mixed.html - xhld/templates/blocks
GL