Design: UI-Bausteine rendern die neuen Klassen (Button, Badge, Card, Kopf, Reiter, Stat)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/components/ui/DurationSelect.jsx

@@ -5,7 +5,7 @@ export default function DurationSelect({ id, value, onChange, disabled }) {
   return (
     <select
       id={id}
-      className="form-control"
+      className="select"
       value={value}
       disabled={disabled}
       onChange={(e) => onChange(Number(e.target.value))}