diff --git a/system_files/etc/gamescope-session-plus/sessions.d/steam b/system_files/etc/gamescope-session-plus/sessions.d/steam
index 258bf80..8a6e958 100644
--- a/system_files/etc/gamescope-session-plus/sessions.d/steam
+++ b/system_files/etc/gamescope-session-plus/sessions.d/steam
@@ -14,6 +14,12 @@ if [[ -n "${ARMADA_PANEL_REFRESH_RATES:-}" ]]; then
         unset STEAM_DISPLAY_REFRESH_LIMITS
     fi
 fi
+# Gamescope only lights up the primary panel; silence the secondary
+# touchscreen so fingers on the dark glass don't move Steam's cursor.
+# The desktop session re-enables it (see desktop-bootstrap).
+if [[ -n "${ARMADA_SECONDARY_TOUCHSCREEN:-}" ]]; then
+    /usr/libexec/armada/touchscreen-inhibit "$ARMADA_SECONDARY_TOUCHSCREEN" 1 2>/dev/null || true
+fi
 USE_ROTATION_SHADER="${ARMADA_GAMESCOPE_USE_ROTATION_SHADER:-0}"
 if [[ -n "${ARMADA_GAMESCOPE_FAKE_OUTPUT_MM:-}" ]]; then
     export GAMESCOPE_FAKE_OUTPUT_MM="$ARMADA_GAMESCOPE_FAKE_OUTPUT_MM"
diff --git a/system_files/usr/bin/steamos-polkit-helpers/steamos-priv-write b/system_files/usr/bin/steamos-polkit-helpers/steamos-priv-write
index 412df77..a039f53 100755
--- a/system_files/usr/bin/steamos-polkit-helpers/steamos-priv-write
+++ b/system_files/usr/bin/steamos-polkit-helpers/steamos-priv-write
@@ -72,5 +72,30 @@ if [[ "$WRITE_PATH" == /sys/class/hwmon/hwmon*/power*_cap ]]; then
     exit 1
 fi
 
+if [[ "$WRITE_PATH" == /sys/class/backlight/*/brightness ]]; then
+    [[ "$WRITE_VALUE" =~ ^[0-9]+$ ]] || exit 1
+    # Steam adjusts the first backlight it finds; on dual-screen devices
+    # that can be the secondary panel. Steer writes to the primary
+    # backlight, rescaling between the two devices' brightness ranges.
+    eval "$(/usr/libexec/armada/device-env)"
+    src_dir="$(dirname "$WRITE_PATH")"
+    tgt_dir="$src_dir"
+    if [[ -n "${ARMADA_PRIMARY_BACKLIGHT:-}" ]]; then
+        tgt_dir="/sys/class/backlight/${ARMADA_PRIMARY_BACKLIGHT}"
+    fi
+    [[ -e "$tgt_dir/brightness" ]] || exit 1
+    val="$WRITE_VALUE"
+    if [[ "$tgt_dir" != "$src_dir" && -e "$src_dir/max_brightness" ]]; then
+        src_max="$(cat "$src_dir/max_brightness")"
+        tgt_max="$(cat "$tgt_dir/max_brightness")"
+        if [[ "$src_max" -gt 0 && "$src_max" -ne "$tgt_max" ]]; then
+            val=$(( val * tgt_max / src_max ))
+        fi
+    fi
+    echo "$val" > "$tgt_dir/brightness"
+    log "backlight: $WRITE_VALUE -> $tgt_dir/brightness ($val)"
+    exit 0
+fi
+
 echo "refusing unsupported write: $WRITE_VALUE -> $WRITE_PATH" >&2
 exit 1
diff --git a/system_files/usr/lib/armada/devices/ayn-thor.conf b/system_files/usr/lib/armada/devices/ayn-thor.conf
index b063aab..0a84172 100644
--- a/system_files/usr/lib/armada/devices/ayn-thor.conf
+++ b/system_files/usr/lib/armada/devices/ayn-thor.conf
@@ -2,7 +2,14 @@ ARMADA_DEVICE_ID=ayn-thor
 ARMADA_DEVICE_NAME='AYN Thor'
 ARMADA_SOC_CLASS=SM8550
 
-ARMADA_PRIMARY_CONNECTOR=DSI-1
+# Dual screen: top panel is DSI-2 (mdss_dsi1), bottom panel is DSI-1
+# (mdss_dsi0). Gamescope drives only the top panel; the desktop session
+# uses both (see desktop-bootstrap).
+ARMADA_PRIMARY_CONNECTOR=DSI-2
+ARMADA_PRIMARY_BACKLIGHT=ae96000.dsi.0
+ARMADA_PRIMARY_TOUCHSCREEN=top_touchscreen
+ARMADA_SECONDARY_CONNECTOR=DSI-1
+ARMADA_SECONDARY_TOUCHSCREEN=bottom_touchscreen
 ARMADA_PANEL_ORIENTATION=right
 ARMADA_PANEL_NATIVE_WIDTH=1080
 ARMADA_PANEL_NATIVE_HEIGHT=1920
diff --git a/system_files/usr/lib/armada/devices/defaults.conf b/system_files/usr/lib/armada/devices/defaults.conf
index 1b162c5..9125821 100644
--- a/system_files/usr/lib/armada/devices/defaults.conf
+++ b/system_files/usr/lib/armada/devices/defaults.conf
@@ -3,6 +3,15 @@ ARMADA_DEVICE_NAME=unknown
 ARMADA_SOC_CLASS=
 
 ARMADA_PRIMARY_CONNECTOR=
+# Backlight Steam brightness writes are steered to. Only needed on devices
+# with more than one backlight (Steam grabs the first one it finds).
+ARMADA_PRIMARY_BACKLIGHT=
+# Set on dual-screen devices; the desktop session extends onto this output.
+ARMADA_SECONDARY_CONNECTOR=
+# Input device names used to pin each touchscreen to its own output in the
+# desktop session (only needed when a secondary connector is set).
+ARMADA_PRIMARY_TOUCHSCREEN=
+ARMADA_SECONDARY_TOUCHSCREEN=
 ARMADA_PANEL_TYPE=internal
 ARMADA_PANEL_ORIENTATION=normal
 ARMADA_PANEL_NATIVE_WIDTH=
diff --git a/system_files/usr/lib/udev/rules.d/60-armada-perf-acls.rules b/system_files/usr/lib/udev/rules.d/60-armada-perf-acls.rules
index 306a54e..1c0be0f 100644
--- a/system_files/usr/lib/udev/rules.d/60-armada-perf-acls.rules
+++ b/system_files/usr/lib/udev/rules.d/60-armada-perf-acls.rules
@@ -4,5 +4,7 @@ SUBSYSTEM=="cpu", KERNEL=="cpu[0-9]*", \
 SUBSYSTEM=="devfreq", KERNEL=="*.gpu", \
     RUN+="/bin/sh -c 'chgrp wheel /sys/class/devfreq/%k/governor /sys/class/devfreq/%k/max_freq /sys/class/devfreq/%k/min_freq 2>/dev/null; chmod g+w /sys/class/devfreq/%k/governor /sys/class/devfreq/%k/max_freq /sys/class/devfreq/%k/min_freq 2>/dev/null'"
 
-SUBSYSTEM=="backlight", \
-    RUN+="/bin/sh -c 'chgrp wheel /sys/class/backlight/%k/brightness 2>/dev/null; chmod g+w /sys/class/backlight/%k/brightness 2>/dev/null'"
+SUBSYSTEM=="backlight", RUN+="/usr/libexec/armada/backlight-acl %k"
+
+SUBSYSTEM=="input", KERNEL=="input[0-9]*", \
+    RUN+="/bin/sh -c 'chgrp wheel /sys/class/input/%k/inhibited 2>/dev/null; chmod g+w /sys/class/input/%k/inhibited 2>/dev/null'"
diff --git a/system_files/usr/libexec/armada/backlight-acl b/system_files/usr/libexec/armada/backlight-acl
new file mode 100755
index 0000000..a718874
--- /dev/null
+++ b/system_files/usr/libexec/armada/backlight-acl
@@ -0,0 +1,16 @@
+#!/usr/bin/bash
+# udev helper: grant Steam (wheel) direct write access to a backlight.
+#
+# On devices with more than one panel (ARMADA_PRIMARY_BACKLIGHT set) the
+# grant is withheld from every backlight: Steam writes the first backlight
+# it finds directly whenever it can, which bypasses the steamos-priv-write
+# steering to the primary panel. Without write access Steam falls back to
+# the polkit helper (its standard path on SteamOS), which steers and
+# rescales the write.
+set -euo pipefail
+
+eval "$(/usr/libexec/armada/device-env)"
+[[ -n "${ARMADA_PRIMARY_BACKLIGHT:-}" ]] && exit 0
+
+chgrp wheel "/sys/class/backlight/$1/brightness" 2>/dev/null || true
+chmod g+w "/sys/class/backlight/$1/brightness" 2>/dev/null || true
diff --git a/system_files/usr/libexec/armada/desktop-bootstrap b/system_files/usr/libexec/armada/desktop-bootstrap
index 1bd9420..badbec7 100755
--- a/system_files/usr/libexec/armada/desktop-bootstrap
+++ b/system_files/usr/libexec/armada/desktop-bootstrap
@@ -20,17 +20,24 @@ else
     systemctl --user import-environment "${activation_env[@]}" 2>/dev/null || true
 fi
 
+if command -v /usr/libexec/armada/device-env >/dev/null 2>&1; then
+    eval "$(/usr/libexec/armada/device-env)"
+fi
+
+# The gaming session inhibits the secondary touchscreen (the desktop is the
+# only session that lights up the secondary panel); re-enable it every start.
+if [[ -n "${ARMADA_SECONDARY_TOUCHSCREEN:-}" ]]; then
+    /usr/libexec/armada/touchscreen-inhibit "$ARMADA_SECONDARY_TOUCHSCREEN" 0 2>/dev/null || true
+fi
+
 config_dir="${XDG_CONFIG_HOME:-${HOME}/.config}/armada"
 rotation_done="${config_dir}/desktop-rotation.done"
 scale_done="${config_dir}/desktop-scale.done"
+dual_done="${config_dir}/desktop-dualscreen.done"
 
-[[ ! -e "${rotation_done}" || ! -e "${scale_done}" ]] || exit 0
+[[ ! -e "${rotation_done}" || ! -e "${scale_done}" || ! -e "${dual_done}" ]] || exit 0
 mkdir -p "${config_dir}"
 
-if command -v /usr/libexec/armada/device-env >/dev/null 2>&1; then
-    eval "$(/usr/libexec/armada/device-env)"
-fi
-
 display_connector="${ARMADA_PRIMARY_CONNECTOR:-}"
 panel_orientation="${ARMADA_PANEL_ORIENTATION:-normal}"
 
@@ -57,3 +64,11 @@ fi
 if [[ ! -e "${scale_done}" ]] && kscreen-doctor "output.${display_connector}.scale.1.5" >/dev/null 2>&1; then
     touch "${scale_done}"
 fi
+
+if [[ ! -e "${dual_done}" ]]; then
+    if [[ -z "${ARMADA_SECONDARY_CONNECTOR:-}" ]]; then
+        touch "${dual_done}"
+    elif /usr/libexec/armada/setup-dual-screen; then
+        touch "${dual_done}"
+    fi
+fi
diff --git a/system_files/usr/libexec/armada/device-env b/system_files/usr/libexec/armada/device-env
index faf005f..239d4ee 100755
--- a/system_files/usr/libexec/armada/device-env
+++ b/system_files/usr/libexec/armada/device-env
@@ -36,6 +36,10 @@ vars=(
     ARMADA_DEVICE_NAME
     ARMADA_SOC_CLASS
     ARMADA_PRIMARY_CONNECTOR
+    ARMADA_PRIMARY_BACKLIGHT
+    ARMADA_SECONDARY_CONNECTOR
+    ARMADA_PRIMARY_TOUCHSCREEN
+    ARMADA_SECONDARY_TOUCHSCREEN
     ARMADA_PANEL_TYPE
     ARMADA_PANEL_ORIENTATION
     ARMADA_PANEL_NATIVE_WIDTH
diff --git a/system_files/usr/libexec/armada/setup-dual-screen b/system_files/usr/libexec/armada/setup-dual-screen
new file mode 100755
index 0000000..08afbb3
--- /dev/null
+++ b/system_files/usr/libexec/armada/setup-dual-screen
@@ -0,0 +1,124 @@
+#!/usr/bin/python3
+"""One-time desktop layout for dual-screen devices, run by desktop-bootstrap.
+
+Places the secondary output below the primary (centered), makes the primary
+the priority-1 output, and pins each touchscreen to its own output so taps
+land on the screen being touched.
+"""
+import glob
+import json
+import shlex
+import subprocess
+import sys
+
+
+def device_env():
+    out = subprocess.run(
+        ["/usr/libexec/armada/device-env"],
+        capture_output=True, text=True, check=True,
+    ).stdout
+    env = {}
+    for line in out.splitlines():
+        key, _, value = line.partition("=")
+        env[key] = shlex.split(value)[0] if value else ""
+    return env
+
+
+def logical_size(output):
+    mode = next(
+        (m for m in output.get("modes", [])
+         if str(m.get("id")) == str(output.get("currentModeId"))),
+        None,
+    )
+    if mode is None:
+        return None
+    width = mode["size"]["width"]
+    height = mode["size"]["height"]
+    # KScreen rotation flags: 2 (left) and 8 (right) swap the axes.
+    if output.get("rotation") in (2, 8):
+        width, height = height, width
+    scale = output.get("scale") or 1
+    return round(width / scale), round(height / scale)
+
+
+def input_devices():
+    """Map input device name -> (vendor, product, event node)."""
+    devices = {}
+    for sysdir in glob.glob("/sys/class/input/input*"):
+        try:
+            name = open(f"{sysdir}/name").read().strip()
+            vendor = int(open(f"{sysdir}/id/vendor").read(), 16)
+            product = int(open(f"{sysdir}/id/product").read(), 16)
+            event = next(
+                e.rsplit("/", 1)[-1] for e in glob.glob(f"{sysdir}/event*")
+            )
+        except (OSError, StopIteration, ValueError):
+            continue
+        devices[name] = (vendor, product, event)
+    return devices
+
+
+def pin_touchscreen(name, connector, devices):
+    if name not in devices:
+        return
+    vendor, product, event = devices[name]
+    # Persisted mapping, applied by KWin when the device is added.
+    subprocess.run(
+        ["kwriteconfig6", "--file", "kcminputrc",
+         "--group", "Libinput", "--group", str(vendor),
+         "--group", str(product), "--group", name,
+         "--key", "OutputName", connector],
+        check=False,
+    )
+    # Live mapping for the current session.
+    subprocess.run(
+        ["gdbus", "call", "--session", "--dest", "org.kde.KWin",
+         "--object-path", f"/org/kde/KWin/InputDevice/{event}",
+         "--method", "org.freedesktop.DBus.Properties.Set",
+         "org.kde.KWin.InputDevice", "outputName", f"<'{connector}'>"],
+        check=False, capture_output=True,
+    )
+
+
+def main():
+    env = device_env()
+    primary = env.get("ARMADA_PRIMARY_CONNECTOR")
+    secondary = env.get("ARMADA_SECONDARY_CONNECTOR")
+    if not primary or not secondary:
+        return 0
+
+    # Some kscreen-doctor versions append human-readable text after the
+    # JSON document, so parse only the first document.
+    doc = subprocess.run(
+        ["kscreen-doctor", "-j"],
+        capture_output=True, text=True, check=True,
+    ).stdout
+    outputs = json.JSONDecoder().raw_decode(doc)[0]["outputs"]
+    by_name = {o["name"]: o for o in outputs}
+    if primary not in by_name or secondary not in by_name:
+        print(f"setup-dual-screen: outputs not found: {primary}, {secondary}",
+              file=sys.stderr)
+        return 1
+
+    primary_size = logical_size(by_name[primary])
+    secondary_size = logical_size(by_name[secondary])
+    if primary_size is None or secondary_size is None:
+        return 1
+    x = max(0, round((primary_size[0] - secondary_size[0]) / 2))
+    subprocess.run(
+        ["kscreen-doctor",
+         f"output.{primary}.priority.1",
+         f"output.{secondary}.priority.2",
+         f"output.{primary}.position.0,0",
+         f"output.{secondary}.position.{x},{primary_size[1]}"],
+        check=True,
+    )
+
+    devices = input_devices()
+    pin_touchscreen(env.get("ARMADA_PRIMARY_TOUCHSCREEN"), primary, devices)
+    pin_touchscreen(env.get("ARMADA_SECONDARY_TOUCHSCREEN"), secondary, devices)
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())
diff --git a/system_files/usr/libexec/armada/touchscreen-inhibit b/system_files/usr/libexec/armada/touchscreen-inhibit
new file mode 100755
index 0000000..7ebc8ab
--- /dev/null
+++ b/system_files/usr/libexec/armada/touchscreen-inhibit
@@ -0,0 +1,12 @@
+#!/usr/bin/bash
+# Inhibit (1) or re-enable (0) an input device by name. Used to silence the
+# secondary touchscreen while gamescope owns the only visible screen.
+set -euo pipefail
+
+name="${1:?usage: touchscreen-inhibit <device-name> <1|0>}"
+state="${2:?usage: touchscreen-inhibit <device-name> <1|0>}"
+
+for dev in /sys/class/input/input*/; do
+    [[ "$(cat "${dev}name" 2>/dev/null)" == "${name}" ]] || continue
+    echo "${state}" > "${dev}inhibited"
+done