[Fix]모달창 위치 조정

회원가입, 로그인 모달창의 z-index를 4000으로 설정
다른 모든 모달 창보다 앞에 위치하도록 변경
Issues #15

client/src/components/Logins/EmailLogin.tsx

@@ -99,6 +99,7 @@ const ModalBackground = styled.div`
 `;
 
 const ModalContainer = styled.div`
+  z-index:4000;
   position: relative;
   background-color: white;
   padding: 20px;

client/src/components/Logins/LoginConfirmatationModal.tsx

@@ -37,6 +37,7 @@ const ModalBackground = styled.div`
 `;
 
 const ModalContainer = styled.div`
+  z-index:4000;
   position: relative;
   background-color: white;
   padding: 20px;

client/src/components/Logins/OAuthLogin.tsx

@@ -64,6 +64,7 @@ const ModalBackground = styled.div`
 `;
 
 const ModalContainer = styled.div`
+    z-index:4000;
     position: relative;
     background-color: white;
     padding: 20px;

client/src/components/Signups/EmailCertify.tsx

@@ -122,7 +122,8 @@ const ModalBackground = styled.div`
 
 // 모달의 컨테이너 스타일
 const ModalContainer = styled.div`
-position: relative;
+  z-index:4000;
+  position: relative;
   background-color: white;
   padding: 20px;
   width: 400px;

client/src/components/Signups/EmailSignup.tsx

@@ -108,6 +108,7 @@ const ModalBackground = styled.div`
 
 //모달 컨테이너
 const ModalContainer = styled.div`
+  z-index:4000;
   position: relative;
   background-color: white;
   padding: 20px;

client/src/components/Signups/Password.tsx

@@ -147,6 +147,7 @@ const ModalBackground = styled.div`
 
 // 모달 컨테이너 스타일
 const ModalContainer = styled.div`
+  z-index:4000;
   position: relative;
   background-color: white;
   padding: 20px;

client/src/components/Signups/Welcome.tsx

@@ -58,6 +58,7 @@ const ModalBackground = styled.div`
 `;
 
 const ModalContainer = styled.div`
+  z-index:4000;
   position: relative;
   background-color: white;
   padding: 20px;