diff --git a/healthcheck-overrides/index.html b/healthcheck-overrides/index.html
index 3feb873..203497d 100644
--- a/healthcheck-overrides/index.html
+++ b/healthcheck-overrides/index.html
@@ -22,10 +22,10 @@
     <meta name="theme-color" content="#080d14">
     <meta name="apple-mobile-web-app-capable" content="yes">
     <link rel="stylesheet" href="/vendor/leaflet/leaflet.css">
-    <link rel="stylesheet" href="/styles.css">
-    <link rel="stylesheet" href="/ukmesh-theme.css">
+    <link rel="stylesheet" href="/styles.css?v=20260413-231700">
+    <link rel="stylesheet" href="/ukmesh-theme.css?v=20260413-231700">
   </head>
-  <body>
+  <body data-map-observer-scope="expected">
     <header class="ukmesh-topbar">
       <a href="https://ukmesh.com" class="ukmesh-topbar__brand">
         <span class="ukmesh-topbar__brand-icon">◈</span>
@@ -154,6 +154,7 @@
           <p class="small-note allowlist-note" id="observer-allowlist-note">
             Default: 0 observers.
           </p>
+          <div class="region-filter hidden" id="region-filter"></div>
           <div class="observer-selector" id="observer-allowlist"></div>
           <div class="panel-divider hidden"></div>
           <div class="panel-header slim hidden">
@@ -233,6 +234,6 @@
     </main>
 
     <script src="/vendor/leaflet/leaflet.js" defer></script>
-    <script type="module" src="/app.js"></script>
+    <script type="module" src="/app.js?v=20260413-231700"></script>
   </body>
 </html>
diff --git a/healthcheck-overrides/ukmesh-theme.css b/healthcheck-overrides/ukmesh-theme.css
index 778045b..ebbe1b0 100644
--- a/healthcheck-overrides/ukmesh-theme.css
+++ b/healthcheck-overrides/ukmesh-theme.css
@@ -195,11 +195,6 @@ body {
   border: 1px solid rgba(0, 196, 255, 0.2);
 }
 
-/* ─── Score ring ─────────────────────────────────────────────────────────── */
-.score-ring__track {
-  stroke: rgba(32, 80, 140, 0.25);
-}
-
 /* ─── Map ────────────────────────────────────────────────────────────────── */
 .observer-map {
   border-radius: 6px;
@@ -256,6 +251,25 @@ body {
   display: none !important;
 }
 
+/* ─── Region filter buttons ──────────────────────────────────────────────── */
+.region-btn {
+  border-color: rgba(32, 80, 140, 0.35);
+  font-family: 'Share Tech Mono', 'Courier New', monospace;
+  letter-spacing: 0.06em;
+}
+
+.region-btn:hover {
+  background: rgba(0, 196, 255, 0.06);
+  border-color: rgba(0, 196, 255, 0.25);
+  color: #d6e8ff;
+}
+
+.region-btn.active {
+  background: rgba(0, 196, 255, 0.1);
+  border-color: rgba(0, 196, 255, 0.45);
+  color: #00c4ff;
+}
+
 /* ─── Scrollbar ──────────────────────────────────────────────────────────── */
 ::-webkit-scrollbar { width: 4px; }
 ::-webkit-scrollbar-track { background: transparent; }
