Modernize UI across all PHP/HTML files with new CSS

[Copilot]

Replaces outdated Bootstrap-based and bare-HTML styling with a consistent, modern dark UI across all PHP/HTML files. No content, functionality, or iframe sizes are touched.

Global additions (all files)

• Google Fonts — Inter (300–800) + JetBrains Mono via preconnect <link> tags
• Ambient background — CSS ::before/::after radial gradient blobs (indigo/purple, no interaction)
• Gradient scrollbars — indigo→purple replacing flat zinc
• -webkit-font-smoothing: antialiased globally

Per-file highlights

• index.php — Glassmorphism header/footer (backdrop-blur-md), gradient logo glow, gradient active nav buttons with glow shadow, archive row hover accent, fade-in on <main>
• modpack.html / modpack2.html — Glass cards with backdrop-blur, glowing progress bar, gradient Upload/Rollout buttons, staggered fadeUp card animations, modernized modal overlay
• debug/index.php — Bootstrap 5 dropped entirely; Tailwind dark theme with terminal-style output panel (macOS-style traffic light dots), categorized gradient action buttons
• maintenance/index.php — Old inline jQuery CSS replaced with Tailwind glass card; status box toggling now uses CSS classes instead of inline background-color
• maintenance/index_new.php — Glass card, logo drop-shadow glow, staggered fade-in animations
• checksum/index.php — Full redesign: Tailwind glass card, gradient submit button, styled result output with emerald/red color coding, JetBrains Mono for hash display

Example: new CSS pattern used throughout

.glass-card {
    background: rgba(24, 24, 27, 0.65);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
}
::-webkit-scrollbar-thumb {
    background: linear-gradient(180deg, #4f46e5, #7c3aed);
    border-radius: 999px;
}

Original prompt

change visuals of each php/html file in this repo, add new css, make it look more modern

however dont touch the content
and iframe size

Created from VS Code.