Lead the card with the event as a headline, make list rows object-first
(item bold, 'Shared by x' beneath), rename the CTA to 'View shared items'
(full-width on mobile), and repeat the dark palette under data-ogsc/-ogsb
for Outlook's apps. Tighten preheader and body copy, align the plain-text
parts, and drop the unused legacy share_by_username/share_by_email
templates.