Improve Trade button visibility on mobile — thicker outline and bolder text

[realproject7]

Summary

The Trade button in the mobile bottom nav is not visually prominent enough. It needs a thicker outline border and bolder button text to stand out as the primary action.

Current behavior

Trade button has a thin outline that blends in with Donate and Rate buttons — all three look equally weighted.

Expected behavior

• Trade button has a thicker border (e.g. border-2 instead of border)
• Trade button text is bolder (e.g. font-bold or font-semibold)
• Trade should visually stand out as the primary CTA among the three buttons

Acceptance Criteria

• Trade button has noticeably thicker outline than Donate/Rate
• Trade button text is bolder
• Visually reads as the primary action on mobile