Quick fixes and polish for a small React landing page

I have a small landing page that needs a bit of cleanup. Nothing huge — mostly fixing a few layout issues on mobile, making the buttons behave properly, and tidying up some spacing and text styles. The page is built in React with a simple component setup, so I need someone who can jump in quickly, make the changes, and keep it lightweight. If you see a couple of easy improvements for Core Web Vitals, feel free to mention them too. Budget is fixed, so this is really for a small task, not a full redesign.