Markdown pipe-tables and hand-written html_fragment <table> markup already
rendered - the only existing rule was 'max-width: 100%', so they came out
as bare, unbordered browser-default tables. Adds borders, header
background, cell padding, and zebra striping, plus a display:block +
overflow-x:auto pattern so wide tables scroll horizontally instead of
squeezing columns or breaking page layout.
Lives in base.css, which report.css and tasks.css both @import, so it
applies to every existing and future markdown/html_fragment artifact
immediately - no agent-side change needed, since this is rendered live
from CSS rather than baked into stored HTML.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>