refactor: css 따로 빼기

Author: 이정원

src/pages/PostPages/WriteLayout/navigator.tsx

@@ -16,9 +16,11 @@ const Navigator = ({ goNext, goPrev, isFirst, isLast }: NavigatorProps) => {
     <footer>
       <div className={s.stepBtn}>
         {!isFirst && (
-          <Btn onClick={goPrev} style={{ flex: '1 1 0' }}>
-            이전
-          </Btn>
+          <div className={s.halfFlex}>
+            <Btn onClick={goPrev}>
+              이전
+            </Btn>
+          </div>
         )}
         <Btn onClick={goNext} color="main" style={isFirst ? { width: '100%' } : { flex: '1 1 0' }}>
           {label}

src/pages/PostPages/WriteLayout/style.css.ts

@@ -42,3 +42,7 @@ export const headerText = css({
   fontSize: '1.25rem',
   fontWeight: '600',
 });
+
+export const halfFlex = css ({
+  flex: '1 1 0'
+})