diff --git a/.github/workflows/gradle.yml b/.github/workflows/gradle.yml
index 8f81a54d2e..064c0dc997 100644
--- a/.github/workflows/gradle.yml
+++ b/.github/workflows/gradle.yml
@@ -21,65 +21,95 @@ jobs:
   build:
 
     runs-on: ubuntu-latest
+    timeout-minutes: 90
 
     steps:
     - uses: actions/checkout@v6
+
+    # Same pattern as TDLM ForestryMC/IndustrialCraft2 setup-build: cache the JDK toolchain.
     - name: Set up JDK 17
       uses: actions/setup-java@v6
       with:
         distribution: 'liberica'
         java-version: '17'
         java-package: 'jdk+fx'
+        cache-jdk: true
+
+    # Nest mirrors github.com/gradle/actions as actions/gradle-actions (also as gradle/actions).
+    # v5 rejects cache-provider; v6 supports it. Default on v6 is "enhanced" (commercial) —
+    # on Gitea use external and cache Gradle home with actions/cache below (org IC2/Forestry pattern).
     - name: Setup Gradle
-      # Nest hosts this under actions/gradle-actions (mirror of github.com/gradle/actions).
-      # uses: gradle/actions/... makes act clone git.nest…/gradle/actions which is not seeded.
-      uses: actions/gradle-actions/setup-gradle@v5
+      uses: actions/gradle-actions/setup-gradle@v6
       with:
         cache-cleanup: never
-        # Only main writes the dependency cache; pull requests read it.
-        cache-read-only: ${{ github.ref != 'refs/heads/main' }}
-    # The repository's wrapper downloads Gradle itself, so cache that download too.
-    - name: Cache Gradle distribution
+        cache-provider: ${{ github.server_url == 'https://github.com' && 'basic' || 'external' }}
+
+    # Cache wrapper + dependency/build caches (covers what setup-gradle skips under external).
+    - name: Cache Gradle home
       uses: actions/cache@v4
       with:
         path: |
+          ~/.gradle/caches
           ~/.gradle/wrapper
           .gradle/wrapper-neo
-        key: gradle-dist-${{ hashFiles('gradle/wrapper/gradle-wrapper.properties', 'gradle/wrapper/GradleWrapperNeo.java') }}
-    - name: Install Xvfb
+        key: gradle-home-${{ runner.os }}-${{ hashFiles('gradle/wrapper/gradle-wrapper.properties', 'gradle/wrapper/GradleWrapperNeo.java', '**/libs.versions.toml', '**/*.gradle.kts', '**/*.gradle') }}
+        restore-keys: |
+          gradle-home-${{ runner.os }}-
+
+    # Xvfb alone is not enough: JavaFX Glass needs GTK/X11 libs or Platform.startup fails with
+    # GtkPlatformFactory "Internal Error" and :HMCL:test can hang (looks like a checkstyle stall).
+    - name: Cache apt packages
+      uses: actions/cache@v4
+      with:
+        path: ~/apt-cache
+        key: apt-javafx-xvfb-${{ runner.os }}-${{ runner.arch }}-1
+
+    - name: Install Xvfb and JavaFX GTK deps
       run: |
-        # Installing is the slowest setup step, so skip it when the runner already has xvfb, and
-        # only refresh the package index when a plain install fails.
-        command -v xvfb-run >/dev/null || sudo apt-get install -y --no-install-recommends xvfb \
-          || { sudo apt-get update && sudo apt-get install -y --no-install-recommends xvfb; }
+        pkgs='xvfb libgtk-3-0 libxtst6 libxxf86vm1 libgl1 libxi6 libx11-6 libxext6 libxrender1'
+        sudo mkdir -p /var/cache/apt/archives/partial
+        if [ -d "${HOME}/apt-cache" ] && [ -n "$(ls -A "${HOME}/apt-cache" 2>/dev/null)" ]; then
+          sudo cp -a "${HOME}/apt-cache/." /var/cache/apt/archives/
+        fi
+        # Prefer cached debs; refresh the index only when install cannot resolve packages.
+        sudo apt-get install -y --no-install-recommends $pkgs \
+          || { sudo apt-get update && sudo apt-get install -y --no-install-recommends $pkgs; }
+        mkdir -p "${HOME}/apt-cache"
+        cp -a /var/cache/apt/archives/*.deb "${HOME}/apt-cache/" 2>/dev/null || true
+
     # One Gradle run builds, tests and runs the code and translation checks, so the
     # project is configured and compiled once instead of in two workflows.
     - name: Build and check with Gradle
       run: xvfb-run --auto-servernum ./gradlew build checkstyle checkTranslations --no-daemon --parallel
       env:
-        JAVA_TOOL_OPTIONS: -Djava.awt.headless=true
+        JAVA_TOOL_OPTIONS: -Djava.awt.headless=true -Dprism.order=sw
         MICROSOFT_AUTH_ID: ${{ secrets.MICROSOFT_AUTH_ID }}
         CURSEFORGE_API_KEY: ${{ secrets.CURSEFORGE_API_KEY }}
+
     - name: Get short SHA
       run: echo "SHORT_SHA=${GITHUB_SHA::7}" >> $GITHUB_ENV
+
     - name: Upload JAR
       uses: actions/upload-artifact@v7
       with:
         name: HMCL-${{ env.SHORT_SHA }}-jar
         path: HMCL/build/libs/HMCL-*.jar
         archive: false
+
     - name: Upload EXE
       uses: actions/upload-artifact@v7
       with:
         name: HMCL-${{ env.SHORT_SHA }}-exe
         path: HMCL/build/libs/HMCL-*.exe
         archive: false
+
     - name: Upload SH
       uses: actions/upload-artifact@v7
       with:
         name: HMCL-${{ env.SHORT_SHA }}-sh
         path: HMCL/build/libs/HMCL-*.sh
         archive: false
+
     - name: Upload DEB
       uses: actions/upload-artifact@v7
       with:
diff --git a/HMCL/src/test/java/org/jackhuang/hmcl/JavaFXLauncher.java b/HMCL/src/test/java/org/jackhuang/hmcl/JavaFXLauncher.java
index db0aeb0a3f..74eec7304f 100644
--- a/HMCL/src/test/java/org/jackhuang/hmcl/JavaFXLauncher.java
+++ b/HMCL/src/test/java/org/jackhuang/hmcl/JavaFXLauncher.java
@@ -10,6 +10,9 @@ import org.jetbrains.annotations.NotNullByDefault;
 import org.jetbrains.annotations.Nullable;
 
 import java.lang.reflect.Field;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
 
 /// Owns the shared JavaFX toolkit for the lifetime of the test process.
 @NotNullByDefault
@@ -27,11 +30,36 @@ public final class JavaFXLauncher {
         System.setProperty("hmcl.scroll.speed", "1");
         try {
             initializeAnimationPolicy();
-            Platform.startup(() -> {
-            });
-            started = true;
-        } catch (IllegalStateException e) {
-            started = true;
+            // Platform.startup can hang when GTK/Glass is broken (minimal CI images with only xvfb).
+            // Bound class-init so :HMCL:test cannot stall the whole Gradle build.
+            CountDownLatch done = new CountDownLatch(1);
+            AtomicReference<Throwable> error = new AtomicReference<>();
+            Thread t = new Thread(() -> {
+                try {
+                    Platform.startup(() -> {
+                    });
+                } catch (Throwable e) {
+                    error.set(e);
+                } finally {
+                    done.countDown();
+                }
+            }, "hmcl-javafx-startup");
+            t.setDaemon(true);
+            t.start();
+            if (!done.await(45, TimeUnit.SECONDS)) {
+                System.err.println("JavaFX Platform.startup timed out; JavaFX tests will be skipped");
+            } else {
+                Throwable e = error.get();
+                if (e == null) {
+                    started = true;
+                } else if (e instanceof IllegalStateException) {
+                    started = true;
+                } else {
+                    e.printStackTrace();
+                }
+            }
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
         } catch (Throwable e) {
             e.printStackTrace();
         }
diff --git a/HMCLCore/src/test/java/org/jackhuang/hmcl/JavaFXLauncher.java b/HMCLCore/src/test/java/org/jackhuang/hmcl/JavaFXLauncher.java
index 334fe46d5d..6afcb63125 100644
--- a/HMCLCore/src/test/java/org/jackhuang/hmcl/JavaFXLauncher.java
+++ b/HMCLCore/src/test/java/org/jackhuang/hmcl/JavaFXLauncher.java
@@ -2,6 +2,10 @@
 // SPDX-License-Identifier: GPL-3.0-or-later WITH AdditionRef-HMCL
 package org.jackhuang.hmcl;
 
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicReference;
+
 public final class JavaFXLauncher {
 
     private JavaFXLauncher() {
@@ -10,13 +14,37 @@ public final class JavaFXLauncher {
     private static boolean started = false;
 
     static {
-        // init JavaFX Toolkit
+        // init JavaFX Toolkit — never block class init forever if GTK/Glass hangs under CI.
         try {
-            javafx.application.Platform.startup(() -> {
-            });
-            started = true;
-        } catch (IllegalStateException e) {
-            started = true;
+            CountDownLatch done = new CountDownLatch(1);
+            AtomicReference<Throwable> error = new AtomicReference<>();
+            Thread t = new Thread(() -> {
+                try {
+                    javafx.application.Platform.startup(() -> {
+                    });
+                } catch (Throwable e) {
+                    error.set(e);
+                } finally {
+                    done.countDown();
+                }
+            }, "hmcl-javafx-startup");
+            t.setDaemon(true);
+            t.start();
+            if (!done.await(45, TimeUnit.SECONDS)) {
+                System.err.println("JavaFX Platform.startup timed out; JavaFX tests will be skipped");
+            } else {
+                Throwable e = error.get();
+                if (e == null) {
+                    started = true;
+                } else if (e instanceof IllegalStateException) {
+                    // Toolkit already running in this JVM.
+                    started = true;
+                } else {
+                    e.printStackTrace();
+                }
+            }
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
         } catch (Throwable e) {
             e.printStackTrace();
         }