diff --git a/.idea/misc.xml b/.idea/misc.xml
index 8e00155..e9b66ee 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="ExternalStorageConfigurationManager" enabled="true" />
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_16" default="true" project-jdk-name="16" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_12" project-jdk-name="16" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>
\ No newline at end of file
diff --git a/build.gradle b/build.gradle
index 67d3e6d..0fff3fa 100644
--- a/build.gradle
+++ b/build.gradle
@@ -18,4 +18,9 @@
 }
 test {
     useJUnitPlatform()
-}
\ No newline at end of file
+}
+java {
+    toolchain {
+        languageVersion = JavaLanguageVersion.of(12)
+    }
+}
diff --git a/src/main/java/views/CardButton.java b/src/main/java/views/CardButton.java
index 3f96a32..3aacc4e 100644
--- a/src/main/java/views/CardButton.java
+++ b/src/main/java/views/CardButton.java
@@ -28,19 +28,19 @@
     }
     public void setStatus(Status status){
         switch (status){
-            case OPEN -> {
+            case OPEN :
                 this.setBackground(OPEN_COLOR);
                 this.setForeground(CLOSED_COLOR);
-            }
-            case CLOSED -> {
+            break;
+            case CLOSED :
                 this.setBackground(CLOSED_COLOR);
                 this.setForeground(OPEN_COLOR);
-            }
-            case MY_CLOSED -> {
+            break;
+            case MY_CLOSED :
                 this.setContentAreaFilled(false);
                 this.setFocusPainted(false); // used for demonstration
                 this.setForeground(OPEN_COLOR);
-            }
+            break;
         }
     }
     @Override