compile .css into .bss file

pom.xml

@@ -298,6 +298,41 @@
 					</compilerArgs>
 				</configuration>
 			</plugin>
+			<plugin>
+				<groupId>org.codehaus.mojo</groupId>
+				<artifactId>exec-maven-plugin</artifactId>
+				<version>3.0.0</version>
+				<executions>
+					<execution>
+						<id>compile-light-theme</id>
+						<phase>compile</phase>
+						<goals>
+							<goal>java</goal>
+						</goals>
+						<configuration>
+							<mainClass>javafx.graphics/com.sun.javafx.css.parser.Css2Bin</mainClass>
+							<arguments>
+								<arg>${project.basedir}/src/main/resources/css/light_theme.css</arg>
+								<arg>${project.build.outputDirectory}/css/light_theme.bss</arg>
+							</arguments>
+						</configuration>
+					</execution>
+					<execution>
+						<id>compile-dark-theme</id>
+						<phase>compile</phase>
+						<goals>
+							<goal>java</goal>
+						</goals>
+						<configuration>
+							<mainClass>javafx.graphics/com.sun.javafx.css.parser.Css2Bin</mainClass>
+							<arguments>
+								<arg>${project.basedir}/src/main/resources/css/dark_theme.css</arg>
+								<arg>${project.build.outputDirectory}/css/dark_theme.bss</arg>
+							</arguments>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-jar-plugin</artifactId>