Make landing page responsive for mobile

[singularitycurse26-svg]

Fixes #3

Changes

Made the landing page fully responsive for mobile devices:

1. Reduced padding on small screens: Changed all px-6 to px-4 sm:px-6 across nav, hero, tools, how-it-works, CTA, and footer sections
2. Responsive ambient glow sizes: Reduced glow div sizes from w-[900px] to w-[600px] sm:w-[900px] and w-[500px] to w-[300px] sm:w-[500px] to prevent overflow on mobile
3. Adjusted vertical padding: Hero section uses pt-16 pb-20 sm:pt-20 sm:pb-24 md:pt-32 md:pb-36 for better mobile spacing
4. Tools grid: Changed from grid-cols-2 sm:grid-cols-4 to grid-cols-2 sm:grid-cols-3 md:grid-cols-4 for better tablet layout
5. Reduced gap: Hero grid gap from gap-12 to gap-8 md:gap-12 for mobile

/claim #3