Create _modifier-keys.scss in package

apps/app/src/styles/style-app.scss

@@ -1,5 +1,6 @@
 @import '@growi/core-styles/scss/helpers/flex-expand';
 @import '@growi/core-styles/scss/helpers/rotate';
+@import '@growi/core-styles/scss/helpers/modifier-keys';
 @import 'mixins';
 
 // atoms
@@ -82,30 +83,6 @@
   }
 }
 
-.cmd-key.mac {
-  &::after {
-    content: '⌘';
-  }
-}
-
-.alt-key.mac {
-  &::after {
-    content: '⌥';
-  }
-}
-
-.cmd-key.win {
-  &::after {
-    content: 'Ctrl';
-  }
-}
-
-.alt-key.win {
-  &::after {
-    content: 'Alt';
-  }
-}
-
 .grw-page-control-dropdown-item {
   display: flex !important;
   align-items: center;

packages/core-styles/scss/helpers/_modifier-keys.scss

@@ -0,0 +1,23 @@
+.cmd-key.mac {
+  &::after {
+    content: '⌘';
+  }
+}
+
+.alt-key.mac {
+  &::after {
+    content: '⌥';
+  }
+}
+
+.cmd-key.win {
+  &::after {
+    content: 'Ctrl';
+  }
+}
+
+.alt-key.win {
+  &::after {
+    content: 'Alt';
+  }
+}