style(exam->ContentLargePage): set exam page width to 100%, make right operation area align left and eliminate right margin on large screens

src/pages/exam/ContentAreaLarge.tsx

@@ -79,7 +79,7 @@ const ContentAreaLarge = () => {
   positionRef.current = selectedBodyPosition;
 
   return (
-    <Row>
+    <Row className="w-full p-1">
       <Col span={20}>
         <Row gutter={16} className="h-full">
           <Col span={4} className="flex flex-col">