git init

app/Http/Middleware/HandleAppearance.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace App\Http\Middleware;
+
+use Closure;
+use Illuminate\Http\Request;
+use Illuminate\Support\Facades\View;
+use Symfony\Component\HttpFoundation\Response;
+
+class HandleAppearance
+{
+    /**
+     * Handle an incoming request.
+     *
+     * @param  Closure(Request): (Response)  $next
+     */
+    public function handle(Request $request, Closure $next): Response
+    {
+        View::share('appearance', $request->cookie('appearance') ?? 'system');
+
+        return $next($request);
+    }
+}