diff --git a/scripts/debian-13-setup.sh b/scripts/debian-13-setup.sh
index 136f852..6532fc2 100755
--- a/scripts/debian-13-setup.sh
+++ b/scripts/debian-13-setup.sh
@@ -294,30 +294,40 @@ if echo "\$KIOSK_URL" | grep -q "localhost"; then
     done
 fi
 
-exec ${CHROMIUM_BIN} \
-    --kiosk \
-    --noerrdialogs \
-    --disable-infobars \
-    --disable-session-crashed-bubble \
-    --disable-features=TranslateUI \
-    --disable-component-update \
-    --check-for-update-interval=31536000 \
-    --autoplay-policy=no-user-gesture-required \
-    --no-first-run \
-    --start-fullscreen \
-    --disable-pinch \
-    --overscroll-history-navigation=0 \
-    --disable-translate \
-    --disable-sync \
-    --disable-background-networking \
-    --disable-default-apps \
-    --disable-extensions \
-    --disable-hang-monitor \
-    --disable-popup-blocking \
-    --disable-prompt-on-repost \
-    --metrics-recording-only \
-    --safebrowsing-disable-auto-update \
-    --ignore-certificate-errors \
+# Detect screen resolution so Chromium fills the display on minimal X11 (no WM)
+SCREEN_RES=\$(xrandr 2>/dev/null | grep ' connected' | grep -oE '[0-9]+x[0-9]+' | head -1)
+SCREEN_W=\${SCREEN_RES%%x*}
+SCREEN_H=\${SCREEN_RES##*x}
+if [ -z "\$SCREEN_W" ] || [ -z "\$SCREEN_H" ]; then
+    SCREEN_W=1920
+    SCREEN_H=1080
+fi
+
+exec ${CHROMIUM_BIN} \\
+    --kiosk \\
+    --window-position=0,0 \\
+    --window-size=\${SCREEN_W},\${SCREEN_H} \\
+    --noerrdialogs \\
+    --disable-infobars \\
+    --disable-session-crashed-bubble \\
+    --disable-features=TranslateUI \\
+    --disable-component-update \\
+    --check-for-update-interval=31536000 \\
+    --autoplay-policy=no-user-gesture-required \\
+    --no-first-run \\
+    --disable-pinch \\
+    --overscroll-history-navigation=0 \\
+    --disable-translate \\
+    --disable-sync \\
+    --disable-background-networking \\
+    --disable-default-apps \\
+    --disable-extensions \\
+    --disable-hang-monitor \\
+    --disable-popup-blocking \\
+    --disable-prompt-on-repost \\
+    --metrics-recording-only \\
+    --safebrowsing-disable-auto-update \\
+    --ignore-certificate-errors \\
     "\$KIOSK_URL"
 KIOSKEOF
 
diff --git a/scripts/raspberry-pi-setup.sh b/scripts/raspberry-pi-setup.sh
index 61a4a08..07fb234 100644
--- a/scripts/raspberry-pi-setup.sh
+++ b/scripts/raspberry-pi-setup.sh
@@ -288,8 +288,19 @@ if echo "\$KIOSK_URL" | grep -q "localhost"; then
     done
 fi
 
+# Detect screen resolution so Chromium fills the display on minimal X11 (no WM)
+SCREEN_RES=\$(xrandr 2>/dev/null | grep ' connected' | grep -oE '[0-9]+x[0-9]+' | head -1)
+SCREEN_W=\${SCREEN_RES%%x*}
+SCREEN_H=\${SCREEN_RES##*x}
+if [ -z "\$SCREEN_W" ] || [ -z "\$SCREEN_H" ]; then
+    SCREEN_W=1920
+    SCREEN_H=1080
+fi
+
 exec ${CHROMIUM_BIN} \\
     --kiosk \\
+    --window-position=0,0 \\
+    --window-size=\${SCREEN_W},\${SCREEN_H} \\
     --noerrdialogs \\
     --disable-infobars \\
     --disable-session-crashed-bubble \\
@@ -298,7 +309,6 @@ exec ${CHROMIUM_BIN} \\
     --check-for-update-interval=31536000 \\
     --autoplay-policy=no-user-gesture-required \\
     --no-first-run \\
-    --start-fullscreen \\
     --disable-pinch \\
     --overscroll-history-navigation=0 \\
     --disable-translate \\