fix(css): shared-page layout – center children with page-width

wwwroot/css/chat.css

@@ -902,13 +902,15 @@
 .shared-page {
   display: flex;
   flex-direction: column;
-  min-height: 100dvh;
-  width: 100%;
-  max-width: var(--page-width);
-  margin: 0 auto;
+  align-items: center;
   overflow: auto;
 }
 
+.shared-page > * {
+  width: var(--page-width);
+  max-width: 100%;
+}
+
 .shared-header {
   display: flex;
   align-items: center;