minor : fix copy effect

src/app/admin/page.tsx

@@ -25,6 +25,7 @@ function AdminPageContent() {
   const [showDeleteModal, setShowDeleteModal] = useState(false);
   const [selectedCampaign, setSelectedCampaign] = useState<Campaign | null>(null);
   const [searchTerm, setSearchTerm] = useState('');
+  const [copiedCampaignId, setCopiedCampaignId] = useState<string | null>(null);
 
   useEffect(() => {
     loadCampaigns();
@@ -83,6 +84,29 @@ function AdminPageContent() {
     return tiers.split(',').map(tier => `${tier.trim()}€`).join(', ');
   };
 
+  const copyToClipboard = async (text: string, campaignId: string) => {
+    try {
+      await navigator.clipboard.writeText(text);
+      setCopiedCampaignId(campaignId);
+      setTimeout(() => setCopiedCampaignId(null), 2000);
+    } catch (error) {
+      console.error('Erreur lors de la copie:', error);
+      // Fallback pour les navigateurs qui ne supportent pas l'API Clipboard
+      const textArea = document.createElement('textarea');
+      textArea.value = text;
+      document.body.appendChild(textArea);
+      textArea.select();
+      try {
+        document.execCommand('copy');
+        setCopiedCampaignId(campaignId);
+        setTimeout(() => setCopiedCampaignId(null), 2000);
+      } catch (fallbackError) {
+        console.error('Erreur avec la méthode de fallback:', fallbackError);
+      }
+      document.body.removeChild(textArea);
+    }
+  };
+
   const filteredCampaigns = campaigns.filter(campaign =>
     campaign.title.toLowerCase().includes(searchTerm.toLowerCase()) ||
     campaign.description.toLowerCase().includes(searchTerm.toLowerCase())
@@ -304,14 +328,14 @@ function AdminPageContent() {
                           className="flex-1 text-sm bg-white dark:bg-slate-800 border-blue-300 dark:border-blue-600 text-blue-700 dark:text-blue-300 font-mono"
                         />
                         <Button
-                          variant="outline"
+                          variant={copiedCampaignId === campaign.id ? "default" : "outline"}
                           size="sm"
                           onClick={() => {
-                            navigator.clipboard.writeText(`${window.location.origin}/campaigns/${campaign.id}/propose`);
+                            copyToClipboard(`${window.location.origin}/campaigns/${campaign.id}/propose`, campaign.id);
                           }}
                           className="text-xs"
                         >
-                          Copier
+                          {copiedCampaignId === campaign.id ? '✓ Copié !' : 'Copier'}
                         </Button>
                       </div>
                     </div>