feat: refactor theme, add tailwind-scrollbar, and improve UI components

- Removed manual theme switching logic and ThemeProvider
- Installed and configured tailwind-scrollbar plugin
- Updated FileConverter and ConversionOptions to use shadcn Input
- Refactored FontSelector to use shadcn Tabs
- Simplified global styles and adjusted glassmorphic effects

app/page.tsx

@@ -1,6 +1,5 @@
 'use client';
 
-import { useEffect } from 'react';
 import AnimatedBackground from '@/components/AnimatedBackground';
 import Hero from '@/components/Hero';
 import Stats from '@/components/Stats';
@@ -9,12 +8,6 @@ import Footer from '@/components/Footer';
 import BackToTop from '@/components/BackToTop';
 
 export default function Home() {
-  useEffect(() => {
-    // Force dark mode on html element for the landing page
-    document.documentElement.classList.remove('light');
-    document.documentElement.classList.add('dark');
-  }, []);
-
   return (
     <main className="relative min-h-screen dark text-foreground">
       <AnimatedBackground />