diff --git a/src/background/ws-client.ts b/src/background/ws-client.ts
index 5443108..988ec71 100644
--- a/src/background/ws-client.ts
+++ b/src/background/ws-client.ts
@@ -32,7 +32,22 @@ interface WireError {
   message: string;
 }
 
-type WireMessage = WireLockState | WireAck | WireError;
+interface WirePong {
+  type: 'pong';
+}
+
+type WireMessage = WireLockState | WireAck | WireError | WirePong;
+
+// JSON-level ping, per the protocol's "ping (optional fallback)" section —
+// used here specifically (not relying on the browser's native WS ping/pong
+// alone) because this client runs in a MV3 background service worker, which
+// Chromium can idle-kill after ~30s with no activity reaching its own
+// onMessage-style handlers; a plain protocol-level ping/pong frame isn't
+// guaranteed to count as that activity, but a JSON message our own
+// 'message' listener below processes is. Sending well under that 30s
+// budget (not waiting until the deadline) keeps the socket (and the
+// worker) alive continuously rather than trying to time a wakeup.
+const PING_INTERVAL_MS = 20_000;
 
 const WIRE_TO_INTERNAL_SCOPE: Record<WireScope, LockScope> = {
   buy_only: 'buy-only',
@@ -95,10 +110,14 @@ export function connectWsClient(options: WsClientOptions): WsClientController {
     const socket = new WebSocket(`${BACKEND_WS_URL}?token=${encodeURIComponent(token)}`);
     currentSocket = socket;
     let authFailure = false;
+    let pingTimer: ReturnType<typeof setInterval> | undefined;
 
     socket.addEventListener('open', () => {
       reconnectAttempt = 0;
       options.onStatusChange('connected');
+      pingTimer = setInterval(() => {
+        if (socket.readyState === WebSocket.OPEN) socket.send(JSON.stringify({ type: 'ping' }));
+      }, PING_INTERVAL_MS);
     });
 
     socket.addEventListener('message', (event) => {
@@ -129,9 +148,12 @@ export function connectWsClient(options: WsClientOptions): WsClientController {
       // 'ack' has nothing to react to yet — the client doesn't send
       // unlock_request/escalate_request until lock-decision logic exists
       // server-side (see backend/CLAUDE.md non-goals for this milestone).
+      // 'pong' likewise needs no handling — sending the ping is the whole
+      // point (see PING_INTERVAL_MS above), receiving a reply isn't acted on.
     });
 
     socket.addEventListener('close', (event) => {
+      if (pingTimer) clearInterval(pingTimer);
       if (currentSocket === socket) currentSocket = undefined;
 
       if (manuallyDisconnected) {
diff --git a/src/content-scripts/interventions/blur-disable.ts b/src/content-scripts/interventions/blur-disable.ts
index 208f038..aa80a90 100644
--- a/src/content-scripts/interventions/blur-disable.ts
+++ b/src/content-scripts/interventions/blur-disable.ts
@@ -20,19 +20,38 @@ const INTERCEPTED_EVENT_TYPES = ['pointerdown', 'mousedown', 'mouseup', 'click']
 const LOCK_ICON_SVG =
   '<svg viewBox="0 0 24 24" width="16" height="16" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"><rect x="4" y="10" width="16" height="10" rx="2"></rect><path d="M8 10V7a4 4 0 0 1 8 0v3"></path></svg>';
 
+// `backdrop-filter` (not `filter`) is deliberate: `filter` on the container
+// would recomposite the container's entire subtree — including the lock
+// icon overlay appended below as its child — as one filtered unit, blurring
+// the icon along with the button (filter/opacity are compositing
+// properties, so a child's own `filter:none` can't opt back out once an
+// ancestor sets one). `backdrop-filter` on the overlay instead only blurs
+// what's painted *behind* the overlay; the overlay's own children (the
+// icon) paint on top of that blurred backdrop unaffected, no DOM
+// restructuring of the site's own (React-owned) nodes required.
 const OVERLAY_STYLE = [
   'position:absolute',
-  'inset:0',
+  // 4px on every side instead of a flush `inset:0`, so the overlay reads as
+  // slightly larger than the pill it's covering rather than exactly
+  // clipped to it.
+  'top:-4px',
+  'bottom:-4px',
+  'left:-4px',
+  'right:-4px',
   'display:flex',
   'align-items:center',
   'justify-content:center',
   'pointer-events:auto',
   'cursor:not-allowed',
   'z-index:2147483000',
-  'filter:none',
-  'opacity:1',
+  // A light blur (vs. the earlier 3px) avoids the pixelated look on small
+  // pill-sized targets; darkening + desaturating the backdrop is what
+  // actually communicates "disabled" here, the blur alone was carrying too
+  // much of that job.
+  'backdrop-filter:blur(1px) grayscale(0.6) brightness(0.55)',
+  '-webkit-backdrop-filter:blur(1px) grayscale(0.6) brightness(0.55)',
+  'background:rgba(0,0,0,0.25)',
   'color:#fff',
-  'background:transparent',
 ].join(';');
 
 /**
@@ -50,8 +69,6 @@ export const blurDisable: Intervention = {
     const originalStyleAttr = container.getAttribute('style');
     const computedPosition = getComputedStyle(container).position;
 
-    container.style.filter = 'blur(3px)';
-    container.style.opacity = '0.5';
     container.style.cursor = 'not-allowed';
     container.style.pointerEvents = 'none';
     if (computedPosition === 'static') {