add max-width for align center

@@ -19,10 +19,11 @@ const Nav = styled.nav`
 
 const HeaderBox = styled.div`
   height: 100%;
+  max-width: 80%;
   display: flex;
   justify-content: space-between;
   align-items: center;
-  margin: 0px 200px;
+  margin: 0 auto;
 `;
 
 const HeaderTitleBox = styled.div`

@@ -13,6 +13,7 @@ const Section = styled.section`
 `;
 
 const SectionBox = styled.div`
+  max-width: 80%;
   display: grid;
   grid-column-gap: 5%;
   grid-template-columns: 40% 50%;