Light-mode `secondary` was `blue` (hue ~260, almost identical to the
`indigo` primary at hue ~277). Result: every primary→secondary
gradient in light mode read as a flat solid colour — Pro pricing tier
border, "Most popular" badge, Pro CTA, hero highlight (when not in
forced-dark sections), stats numbers, comparison-table accents all
lost their gradient direction.
Switch light secondary to `teal` (hue ~182). Dark mode already used
teal, so this unifies the brand pairing across modes. Visible gradient
direction restored everywhere primary→secondary is used.
No block changes needed — the fix lives in the theme palette where
similar brand decisions belong, not as workarounds in individual
blocks.