fix: add responsive padding to Footer for mobile screens

[SG170]

Summary

Fixes #[replace this with your issue number]

Problem

The Footer component was using hardcoded px-16 padding on all screen sizes.
On mobile screens (375px), this caused 64px of side padding which significantly
squeezed the footer content and made it look cramped.

Fix

Updated the padding class in src/components/Footer.jsx from:
px-16
to:
px-5 sm:px-8 lg:px-16
This matches the responsive padding pattern already used by every other section
on the site (Hero, Pillars, Mentors, SummerOfAI, etc.)

Tested On

• Mobile 375px ✅
• Tablet 768px ✅
• Desktop 1280px ✅

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[SG170]

Hey @escher-m I have made the required changes in this pr please review it.
Thank you!!