style(exam->device): increase horizontal spacing between buttons in device area

src/pages/exam/DeviceArea.tsx

@@ -19,12 +19,13 @@ const DeviceArea = ({ className }: { className?: string }) => {
     (state: RootState) => state.deviceArea.tabletStatus
   );
   const btnStyle = { width: '1.5rem', height: '1.5rem' };
-  //const classValue='m-1';
+  const classValue = 'mr-1';
 
   return (
     <Flex justify="end" align="center" className={`w-full ${className}`}>
       <Button
         style={btnStyle}
+        className={classValue}
         icon={
           <ToolOutlined
             className={
@@ -42,6 +43,7 @@ const DeviceArea = ({ className }: { className?: string }) => {
       />
       <Button
         style={btnStyle}
+        className={classValue}
         icon={
           <CameraOutlined
             className={
@@ -57,6 +59,7 @@ const DeviceArea = ({ className }: { className?: string }) => {
       />
       <Button
         style={btnStyle}
+        className={classValue}
         icon={
           <TabletOutlined
             className={