style: update grid layout for SignersList with improved column sizes and centering

Author: ThorstenSuckow

src/components/SignersList.module.css

@@ -17,21 +17,25 @@
     padding: 0;
     margin: 0;
     display: grid;
-    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
+    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
     gap: 12px;
+    max-width: 760px;
+    margin-left: auto;
+    margin-right: auto;
 }
 
 /* Full variant for signatories page - more columns, fixed width */
 .gridFull {
     grid-template-columns: repeat(auto-fill, minmax(200px, 200px));
     gap: 16px;
     justify-content: start;
+    max-width: none;
 }
 
 /* Responsive grid adjustments */
 @media (min-width: 1200px) {
     .grid {
-        grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
+        grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
         gap: 14px;
     }