Add responsive CSS for mobile-friendly layout

[Copilot]

The Twitter archive layout was not optimized for mobile devices, causing usability issues with fixed font sizes, inadequate touch targets, and horizontal overflow.

Changes

Responsive Typography

• Fluid font scaling with clamp(): tweets 18px→26px, primary count 2em→4em
• Responsive headings (h1-h4) for mobile hierarchy

Layout & Navigation

• Sidebar: sticky 20rem on desktop, full-width top section on mobile (<768px)
• Navigation: stacked full-width items on mobile with 44px touch targets
• Main content: reduced padding from 2rem to 1rem on mobile
• Flex layouts (.lo, .lo-cols): stack to 100% width on mobile

Overflow Prevention

• overflow-x: hidden on html/body
• Word-breaking for code blocks, URLs, and long text
• Tweet media: flex-wrap enabled, full-width on mobile

Touch Optimization

• Minimum 44px height for buttons, inputs, links
• Pagination: full-width stacked buttons on mobile
• Header avatar: scales 40px (mobile) to 52px (desktop)

Breakpoint Strategy

Single breakpoint at 48em (768px) using mobile-first approach. Base styles target 320px+ devices.

/* Example: Responsive tweet font sizing */
.tweet {
  font-size: clamp(1.125em, 2vw, 1.625em); /* 18px mobile to 26px desktop */
}

@media (max-width: 48em) {
  .sidebar {
    width: 100%;
    position: static;
    height: auto;
  }
}

Screenshots

Desktop (1280x768)

Mobile (375x667)

Tablet (768x1024)

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• https://api.github.com/repos/CloudCannon/pagefind/releases/tags/v0.10.7
  • Triggering command: /usr/local/bin/node node ./lib/postinstall.js (http block)
• pbs.twimg.com
  • Triggering command: /usr/local/bin/node node /home/REDACTED/work/tweetback/tweetback/node_modules/.bin/eleventy --quiet (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

Enhance the application’s layout and components for a responsive and mobile-friendly interface. Tasks included auditing pages, updating CSS for responsiveness, testing on various devices, fixing overflows/scaling issues, and documenting responsive development.

This pull request was created from Copilot chat.

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