Add glassmorphism to content panels (glossy…

Details

Give the cards a prestigious frosted-glass feel over the animated
background:
- New v2-glass mixin: translucent tinted background + diagonal sheen,
  glass edge highlight (inset top + 1px translucent border), soft drop
  shadow, and backdrop-filter blur+saturate.
- Applied to the hero portrait frame, pillar cards, the section/award/
  publication cards (.v2-prose-paragraphs p), and the theme/weather
  toggle buttons. (The nav was already frosted.)
- Theme-aware glass tokens (dark + light). @supports fallback to the
  opaque card colors where backdrop-filter is unsupported, so panels
  stay readable.

Files changed (1)