diff --git a/docs/architecture/chrome-service.md b/docs/architecture/chrome-service.md
index ba1a853c..c048894c 100644
--- a/docs/architecture/chrome-service.md
+++ b/docs/architecture/chrome-service.md
@@ -170,7 +170,10 @@ minor, with Python-side bindings pre-installed.
   Authentik-gated. The bare host serves `vnc.html` (image symlinks
   `index.html → vnc.html`); add `?autoconnect=true&resize=scale&path=websockify`
   to skip the Connect button. The view is **black when no browser window is
-  open** (idle) — that is normal, not a failed connection.
+  open** (idle) — that is normal, not a failed connection. Chrome is launched
+  with `--window-size=1280,720 --window-position=0,0` to fill the Xvfb screen
+  (no window manager runs, so without it Chrome opens at its profile-persisted
+  size and the rest of the framebuffer shows as a black cut-off).
 
 ### noVNC fd-sweep gotcha (stuck "Connecting")
 
diff --git a/stacks/chrome-service/main.tf b/stacks/chrome-service/main.tf
index c1dd48a8..7d370fbd 100644
--- a/stacks/chrome-service/main.tf
+++ b/stacks/chrome-service/main.tf
@@ -252,6 +252,8 @@ resource "kubernetes_deployment" "chrome_service" {
               --disable-dev-shm-usage \
               --password-store=basic \
               --use-mock-keychain \
+              --window-position=0,0 \
+              --window-size=1280,720 \
               about:blank
             EOT
           ]