diff --git a/.gitea/workflows/ci.yml b/.gitea/workflows/ci.yml
index 2922ff5..b97e3d0 100644
--- a/.gitea/workflows/ci.yml
+++ b/.gitea/workflows/ci.yml
@@ -35,39 +35,25 @@ jobs:
       # Flutter on PATH, so: use it if present (PATH / FLUTTER_ROOT / common
       # dirs), otherwise install the pinned SDK from the flutter-io.cn mirror
       # into a persistent dir (C:\flutter-ci) that is reused across runs.
-      - name: Set up Flutter
+      # Pin Flutter 3.44.2 DETERMINISTICALLY. pdfrx needs Windows stylus +
+      # multitouch, which only landed in Flutter 3.44.0 (WM_POINTER migration).
+      # We install into a version-pinned dir and PREPEND it to PATH so this
+      # version shadows any older Flutter already on the runner (a stale
+      # C:\flutter-ci from prior runs must NOT win, or pen input breaks again).
+      - name: Set up Flutter (pinned 3.44.2)
         shell: powershell
         run: |
           $ErrorActionPreference = 'Stop'
           $ProgressPreference = 'SilentlyContinue'
-          if (Get-Command flutter -ErrorAction SilentlyContinue) {
-            Write-Host "flutter already on PATH"; exit 0
-          }
-          $candidates = @()
-          if ($env:FLUTTER_ROOT) { $candidates += (Join-Path $env:FLUTTER_ROOT 'bin') }
-          $candidates += @(
-            'C:\flutter-ci\flutter\bin','C:\flutter\bin','C:\src\flutter\bin',
-            'C:\tools\flutter\bin','C:\dev\flutter\bin',
-            "$env:USERPROFILE\flutter\bin","$env:LOCALAPPDATA\flutter\bin"
-          )
-          foreach ($c in $candidates) {
-            if ($c -and (Test-Path (Join-Path $c 'flutter.bat'))) {
-              Write-Host "Found Flutter at $c"
-              Add-Content -Path $env:GITHUB_PATH -Value $c
-              exit 0
-            }
-          }
-          # Install the pinned SDK from the China mirror into a persistent dir.
-          $root = 'C:\flutter-ci'
+          $ver  = '3.44.2'
+          $root = "C:\flutter-$ver"
           $bin  = Join-Path $root 'flutter\bin'
           if (-not (Test-Path (Join-Path $bin 'flutter.bat'))) {
-            $url = 'https://storage.flutter-io.cn/flutter_infra_release/releases/stable/windows/flutter_windows_3.41.4-stable.zip'
-            $zip = Join-Path $env:TEMP 'flutter_sdk.zip'
+            $url = "https://storage.flutter-io.cn/flutter_infra_release/releases/stable/windows/flutter_windows_$ver-stable.zip"
+            $zip = Join-Path $env:TEMP "flutter_$ver.zip"
             New-Item -ItemType Directory -Force -Path $root | Out-Null
-            Write-Host "Downloading Flutter SDK from $url"
+            Write-Host "Downloading Flutter $ver from $url"
             $ok = $false
-            # curl.exe (bundled on Windows 10+) streams to disk and is far
-            # faster than Invoke-WebRequest for a ~1GB file. Fall back to IWR.
             $curl = "$env:SystemRoot\System32\curl.exe"
             if (Test-Path $curl) {
               & $curl -L --fail --retry 3 --retry-delay 5 -o $zip $url
@@ -80,16 +66,18 @@ jobs:
                 catch { Write-Host "IWR attempt $i failed: $_"; Start-Sleep 5 }
               }
             }
-            if (-not $ok) { Write-Error "Failed to download Flutter SDK"; exit 1 }
-            Write-Host "Extracting to $root (this is slow on first run)"
+            if (-not $ok) { Write-Error "Failed to download Flutter $ver"; exit 1 }
+            Write-Host "Extracting to $root (slow on first run)"
             Expand-Archive -Path $zip -DestinationPath $root -Force
             Remove-Item $zip -Force
           }
           if (-not (Test-Path (Join-Path $bin 'flutter.bat'))) {
-            Write-Error "Flutter install failed"; exit 1
+            Write-Error "Flutter $ver install failed"; exit 1
           }
-          Write-Host "Flutter ready at $bin"
+          # Prepend (first line wins in GITHUB_PATH) so 3.44.2 shadows any
+          # system/cached Flutter on the runner.
           Add-Content -Path $env:GITHUB_PATH -Value $bin
+          Write-Host "Flutter $ver pinned at $bin"
 
       - name: Flutter version
         run: flutter --version
diff --git a/pubspec.lock b/pubspec.lock
index 1df2208..97a93a3 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -125,10 +125,10 @@ packages:
     dependency: transitive
     description:
       name: characters
-      sha256: f71061c654a3380576a52b451dd5532377954cf9dbd272a78fc8479606670803
+      sha256: faf38497bda5ead2a8c7615f4f7939df04333478bf32e4173fcb06d428b5716b
       url: "https://pub.dev"
     source: hosted
-    version: "1.4.0"
+    version: "1.4.1"
   checked_yaml:
     dependency: transitive
     description:
@@ -635,26 +635,26 @@ packages:
     dependency: transitive
     description:
       name: matcher
-      sha256: dc58c723c3c24bf8d3e2d3ad3f2f9d7bd9cf43ec6feaa64181775e60190153f2
+      sha256: dc0b7dc7651697ea4ff3e69ef44b0407ea32c487a39fff6a4004fa585e901861
       url: "https://pub.dev"
     source: hosted
-    version: "0.12.17"
+    version: "0.12.19"
   material_color_utilities:
     dependency: transitive
     description:
       name: material_color_utilities
-      sha256: f7142bb1154231d7ea5f96bc7bde4bda2a0945d2806bb11670e30b850d56bdec
+      sha256: "9c337007e82b1889149c82ed242ed1cb24a66044e30979c44912381e9be4c48b"
       url: "https://pub.dev"
     source: hosted
-    version: "0.11.1"
+    version: "0.13.0"
   meta:
     dependency: transitive
     description:
       name: meta
-      sha256: "23f08335362185a5ea2ad3a4e597f1375e78bce8a040df5c600c8d3552ef2394"
+      sha256: "1741988757a65eb6b36abe716829688cf01910bbf91c34354ff7ec1c3de2b349"
       url: "https://pub.dev"
     source: hosted
-    version: "1.17.0"
+    version: "1.18.0"
   mime:
     dependency: transitive
     description:
@@ -1184,10 +1184,10 @@ packages:
     dependency: transitive
     description:
       name: test_api
-      sha256: ab2726c1a94d3176a45960b6234466ec367179b87dd74f1611adb1f3b5fb9d55
+      sha256: "949a932224383300f01be9221c39180316445ecb8e7547f70a41a35bf421fb9e"
       url: "https://pub.dev"
     source: hosted
-    version: "0.7.7"
+    version: "0.7.11"
   timing:
     dependency: transitive
     description:
@@ -1374,4 +1374,4 @@ packages:
     version: "3.1.3"
 sdks:
   dart: ">=3.10.8 <4.0.0"
-  flutter: ">=3.41.0"
+  flutter: ">=3.44.0"
diff --git a/pubspec.yaml b/pubspec.yaml
index e9e4c82..59b57c7 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -5,6 +5,10 @@ version: 0.1.0+1
 
 environment:
   sdk: ^3.10.8
+  # pdfrx + Surface Pen require Windows stylus/multitouch, which only exists
+  # in Flutter 3.44+ (WM_POINTER migration, PR #165323). Building on older
+  # Flutter silently breaks pen input on Windows.
+  flutter: ">=3.44.0"
 
 dependencies:
   flutter: