Big first commit

authentication-zero and first layout

app/helpers/application_helper.rb

@@ -1,2 +1,36 @@
 module ApplicationHelper
+  def nav_link_class(target_controller)
+    base_classes = "flex items-center gap-3 px-3 py-2.5 text-sm font-medium rounded-lg transition-colors duration-200"
+
+    if controller_name == target_controller
+      "#{base_classes} bg-blue-50 text-blue-600 font-semibold"
+    else
+      "#{base_classes} text-gray-700 hover:bg-gray-50"
+    end
+  end
+
+  def parse_user_agent(user_agent_string)
+    ua = user_agent_string.to_s.downcase
+
+    # Browser-Erkennung via Case-Regex (nutzt === im Hintergrund)
+    browser = case ua
+    when /firefox/ then "Firefox"
+    when /chrome/  then "Chrome"
+    when /safari/  then "Safari"
+    when /edge/    then "Edge"
+    else "Unbekannter Browser"
+    end
+
+    # Betriebssystem-Erkennung via Case-Regex
+    os = case ua
+    when /windows/   then "Windows"
+    when /macintosh|mac os/ then "macOS"
+    when /iphone/    then "iPhone"
+    when /android/   then "Android"
+    when /linux/     then "Linux"
+    else "Betriebssystem"
+    end
+
+    "#{browser} auf #{os}"
+  end
 end