fix: 주문 완료 컨테이너 수정

Author: choihooo

src/pages/cart/CartPage.tsx

@@ -14,6 +14,7 @@ const CartPageContainer = styled.div`
   flex-direction: column;
   width: 100%;
   color: #111827;
+  box-sizing: border-box;
 `;
 
 const Section = styled.div`

src/pages/cart/OrderConfirmPage.tsx

@@ -17,6 +17,7 @@ const OrderConfirmPageContainer = styled.div`
   max-width: 500px;
   margin: 0 auto;
   color: #111827;
+  box-sizing: border-box;
 `;
 
 const Section = styled.div`

src/pages/cart/OrderSuccessPage.tsx

@@ -11,6 +11,7 @@ const OrderSuccessPageContainer = styled.div`
   margin: 0 auto;
   color: #111827;
   padding: 24px 16px;
+  box-sizing: border-box;
 `;
 
 const PrimaryBtn = styled.button`