diff --git a/app/build.gradle b/app/build.gradle
index 5ddb7bb7..da228679 100755
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -52,9 +52,6 @@ android {
         }
     }
 
-    lintOptions {
-        abortOnError true
-    }
 
     ndkVersion '26.2.11394342'
 
@@ -87,11 +84,15 @@ android {
     }
 
     namespace "helium314.keyboard.latin"
+    lint {
+        abortOnError true
+    }
 }
 
 dependencies {
     // androidx
     implementation 'androidx.core:core-ktx:1.13.1'
+    implementation 'androidx.appcompat:appcompat:1.7.0'
     implementation 'androidx.preference:preference:1.2.1'
     implementation 'androidx.recyclerview:recyclerview:1.3.2'
     implementation 'androidx.autofill:autofill:1.1.0'
@@ -99,8 +100,6 @@ dependencies {
     // kotlin
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
     implementation "org.jetbrains.kotlinx:kotlinx-serialization-json:1.6.3"
-    // when kotlin-serialization is enabled, Android Studio stops complaining about "Unresolved reference: serializer", but the build fails
-//    implementation "org.jetbrains.kotlin:kotlin-serialization:$kotlin_version"
 
     // color picker for user-defined colors
     implementation 'com.github.martin-stone:hsv-alpha-color-picker-android:3.1.0'
diff --git a/app/src/main/java/helium314/keyboard/latin/settings/AppearanceSettingsFragment.kt b/app/src/main/java/helium314/keyboard/latin/settings/AppearanceSettingsFragment.kt
index d372633e..df1969b2 100644
--- a/app/src/main/java/helium314/keyboard/latin/settings/AppearanceSettingsFragment.kt
+++ b/app/src/main/java/helium314/keyboard/latin/settings/AppearanceSettingsFragment.kt
@@ -156,8 +156,9 @@ class AppearanceSettingsFragment : SubScreenFragment() {
             summary = entries[entryValues.indexOfFirst { it == value }]
         }
         dayNightPref?.onPreferenceChangeListener = Preference.OnPreferenceChangeListener { _, value ->
-            colorsNightPref?.isVisible = value as Boolean
-            userColorsPrefNight?.isVisible = value && colorsNightPref?.value == KeyboardTheme.THEME_USER_NIGHT
+            val yesThisIsBoolean = value as Boolean // apparently kotlin smartcast got less smart with 2.0.0
+            colorsNightPref?.isVisible = yesThisIsBoolean
+            userColorsPrefNight?.isVisible = yesThisIsBoolean && colorsNightPref?.value == KeyboardTheme.THEME_USER_NIGHT
             true
         }
         colorsNightPref?.isVisible = dayNightPref?.isChecked == true
diff --git a/build.gradle b/build.gradle
index 83e31cf3..babb04ad 100755
--- a/build.gradle
+++ b/build.gradle
@@ -1,13 +1,13 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
-    ext.kotlin_version = '1.9.24'
+    ext.kotlin_version = '2.0.0'
     repositories {
         mavenCentral()
         google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:8.1.4' // 8.2 requires newer Android Studio that is even worse than 2022.x in performance
+        classpath 'com.android.tools.build:gradle:8.4.1'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
         classpath "org.jetbrains.kotlin:kotlin-serialization:$kotlin_version"
 
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 7f93135c..d64cd491 100755
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 46671acb..8a1f6b97 100755
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,7 +1,7 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionSha256Sum=3e1af3ae886920c3ac87f7a91f816c0c7c436f276a6eefdb3da152100fef72ae
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
+distributionSha256Sum=a4b4158601f8636cdeeab09bd76afb640030bb5b144aafe261a5e8af027dc612
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.8-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
diff --git a/gradlew b/gradlew
index 0adc8e1a..1aa94a42 100755
--- a/gradlew
+++ b/gradlew
@@ -145,7 +145,7 @@ if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
     case $MAX_FD in #(
       max*)
         # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC3045
+        # shellcheck disable=SC2039,SC3045
         MAX_FD=$( ulimit -H -n ) ||
             warn "Could not query maximum file descriptor limit"
     esac
@@ -153,7 +153,7 @@ if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
       '' | soft) :;; #(
       *)
         # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
-        # shellcheck disable=SC3045
+        # shellcheck disable=SC2039,SC3045
         ulimit -n "$MAX_FD" ||
             warn "Could not set maximum file descriptor limit to $MAX_FD"
     esac
@@ -202,11 +202,11 @@ fi
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
 DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
-# Collect all arguments for the java command;
-#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
-#     shell script including quotes and variable substitutions, so put them in
-#     double quotes to make sure that they get re-expanded; and
-#   * put everything else in single quotes, so that it's not re-expanded.
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
 
 set -- \
         "-Dorg.gradle.appname=$APP_BASE_NAME" \
diff --git a/gradlew.bat b/gradlew.bat
index 6689b85b..7101f8e4 100755
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -43,11 +43,11 @@ set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
 if %ERRORLEVEL% equ 0 goto execute
 
-echo.
-echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
 
 goto fail
 
@@ -57,11 +57,11 @@ set JAVA_EXE=%JAVA_HOME%/bin/java.exe
 
 if exist "%JAVA_EXE%" goto execute
 
-echo.
-echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
 
 goto fail