Center and limit content width for better display on large screens

Introduces a new CSS class `.container` with `max-width: 1200px` and `margin: 0 auto` to center content. This class is applied to main content areas in `FolxStadlPage.tsx`, `VideoPage.tsx`, and `home.tsx` to resolve layout stretching issues on wide monitors.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 890577b1-c154-40a4-a177-a0c6d55320c3
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/8cc42625-c1f5-4e43-99bd-77f2c4dedee2/890577b1-c154-40a4-a177-a0c6d55320c3/SHCPaqp

client/src/pages/FolxStadlPage.tsx

@@ -59,7 +59,7 @@ export default function FolxStadlPage() {
     <div className="min-h-screen bg-bunny-dark text-white has-fixed-header">
       {/* Header */}
       <div className="header-sticky bg-transparent overflow-hidden">
-        <div className="max-w-7xl mx-auto px-4 py-4">
+        <div className="container py-4">
           <div className="flex items-center justify-between">
             {/* Left side - Logo */}
             <div className="flex items-center space-x-4">
@@ -154,7 +154,7 @@ export default function FolxStadlPage() {
       </div>
 
       {/* Main Content */}
-      <div className="max-w-7xl mx-auto px-4 py-8">
+      <div className="container py-8">
 
         {/* Video List with Descriptions */}
         <div className="space-y-6">