diff --git a/.phase31-state.json b/.phase31-state.json
index d8f89bf..1933763 100644
--- a/.phase31-state.json
+++ b/.phase31-state.json
@@ -1,8 +1,9 @@
 {
   "completed_features": [],
-  "current_feature": "empty-state-illustrations",
+  "current_feature": "button-loading-states",
   "started_at": "2026-05-23T09:33:26.338003",
   "attempted_features": [
-    "toast-undo-pattern"
+    "toast-undo-pattern",
+    "empty-state-illustrations"
   ]
 }
\ No newline at end of file
diff --git a/GENERATION_LOG.md b/GENERATION_LOG.md
index 7ee6949..f0e0579 100644
--- a/GENERATION_LOG.md
+++ b/GENERATION_LOG.md
@@ -3518,3 +3518,21 @@ src/index.ts(27,25): error TS2769: No overload matches this call.
   Overload 1 of 3, '(plugin: FastifyPluginCallback<{ limits: { fileSize: number; }; }, RawServerDefault, FastifyTypeProvider, FastifyBaseLogger>, opts?: FastifyRegisterOptions<...> | undefined): FastifyInstance<...> & PromiseLike<...>', gave the following error.
     Argument of type 'Promise<FastifyMultipartPlugin>' is not assignable to parameter of type 'FastifyPluginCallback<{ limits: { fileSize: number; }; }, RawServerDefault, FastifyTypeProvider, FastifyBaseLogger>'.
       Type 'Promise<FastifyMultipartPlugin>' provides no match for the signature '(instance: FastifyInstance<RawServerDefault, IncomingMessage, ServerResponse<IncomingMessage>, 
+- `09:33:49` **INFO**   Committed feature empty-state-illustrations
+- `09:33:49` **INFO**   Pushed: rc=0
+
+## Phase-3 Feature: button-loading-states (2026-05-23 09:33:49)
+
+- `09:33:49` **INFO** Description: Button mit loading-prop zeigt Spinner
+- `09:33:49` **INFO**   Generating apps/web/src/components/Button.tsx (Button-Component. Props: variant ('primary'|'secondary'|'danger'), loa…)
+- `09:34:01` **INFO**     wrote 1265 chars in 11.7s (attempt 1)
+- `09:34:01` **INFO** Running tsc --noEmit on api…
+- `09:34:02` **WARN**   tsc errors:
+src/db/schema.ts(37,14): error TS7022: 'customers' implicitly has type 'any' because it does not have a type annotation and is referenced directly or indirectly in its own initializer.
+src/db/schema.ts(45,59): error TS7024: Function implicitly has return type 'any' because it does not have a return type annotation and is referenced directly or indirectly in one of its return expressions.
+src/db/schema.ts(49,14): error TS7022: 'projects' implicitly has type 'any' because it does not have a type annotation and is referenced directly or indirectly in its own initializer.
+src/db/schema.ts(53,56): error TS7024: Function implicitly has return type 'any' because it does not have a return type annotation and is referenced directly or indirectly in one of its return expressions.
+src/index.ts(27,25): error TS2769: No overload matches this call.
+  Overload 1 of 3, '(plugin: FastifyPluginCallback<{ limits: { fileSize: number; }; }, RawServerDefault, FastifyTypeProvider, FastifyBaseLogger>, opts?: FastifyRegisterOptions<...> | undefined): FastifyInstance<...> & PromiseLike<...>', gave the following error.
+    Argument of type 'Promise<FastifyMultipartPlugin>' is not assignable to parameter of type 'FastifyPluginCallback<{ limits: { fileSize: number; }; }, RawServerDefault, FastifyTypeProvider, FastifyBaseLogger>'.
+      Type 'Promise<FastifyMultipartPlugin>' provides no match for the signature '(instance: FastifyInstance<RawServerDefault, IncomingMessage, ServerResponse<IncomingMessage>, 
diff --git a/apps/web/src/components/Button.tsx b/apps/web/src/components/Button.tsx
new file mode 100644
index 0000000..d8375cc
--- /dev/null
+++ b/apps/web/src/components/Button.tsx
@@ -0,0 +1,47 @@
+import React from 'react';
+import { Loader2 } from 'lucide-react';
+
+type ButtonVariant = 'primary' | 'secondary' | 'danger';
+
+interface ButtonProps extends React.ButtonHTMLAttributes<HTMLButtonElement> {
+  variant?: ButtonVariant;
+  loading?: boolean;
+  children: React.ReactNode;
+}
+
+const variantClasses: Record<ButtonVariant, string> = {
+  primary: 'bg-blue-600 text-white hover:bg-blue-700 focus:ring-blue-500',
+  secondary: 'bg-gray-200 text-gray-800 hover:bg-gray-300 focus:ring-gray-400',
+  danger: 'bg-red-600 text-white hover:bg-red-700 focus:ring-red-500',
+};
+
+export default function Button({
+  variant = 'primary',
+  loading = false,
+  disabled,
+  children,
+  className = '',
+  ...props
+}: ButtonProps) {
+  const isDisabled = disabled || loading;
+
+  return (
+    <button
+      disabled={isDisabled}
+      className={`
+        inline-flex items-center justify-center px-4 py-2 rounded-md font-medium transition-colors 
+        focus:outline-none focus:ring-2 focus:ring-offset-2 
+        disabled:opacity-50 disabled:cursor-not-allowed
+        ${variantClasses[variant]} 
+        ${className}
+      `}
+      {...props}
+    >
+      {loading ? (
+        <Loader2 className="w-4 h-4 animate-spin" />
+      ) : (
+        children
+      )}
+    </button>
+  );
+}
\ No newline at end of file