feat: recruitCard 스켈레톤 이미지 추가

src/pages/recruit/RecruitCard.tsx

@@ -63,7 +63,7 @@ export default function RecruitCard({
 
   return (
     <RecruitContainer>
-      <CompanyImg alt="companyImg" src={imageUrl} />
+      {imageUrl ? <CompanyImg alt="companyImg" src={imageUrl} /> : <SkeletonImg />}
       <Info_Div>
         <Info_p>
           <p>{koreanTitle}</p>
@@ -125,7 +125,7 @@ const CompanyImg = styled.img<React.ImgHTMLAttributes<HTMLImageElement>>`
 
   border-radius: 20px;
   object-fit: cover;
-
+  display: ${(props) => (props.src ? 'block' : 'none')};
   @media (max-width: 768px) {
     height: 300px;
   }
@@ -189,3 +189,28 @@ const CustomBtn = styled(Button)<{ background?: string; color?: string; width?:
     width: ${(props) => props.width || '160px'};
   }
 `;
+
+const SkeletonImg = styled.div`
+  width: 100%;
+  height: 380px;
+  border-radius: 20px;
+  background: linear-gradient(90deg, #e0e0e0 25%, #f5f5f5 50%, #e0e0e0 75%);
+  background-size: 300% 100%;
+  animation: shimmer 5s infinite linear;
+
+  @media (max-width: 768px) {
+    height: 300px;
+  }
+  @media (max-width: 480px) {
+    height: 220px;
+  }
+
+  @keyframes shimmer {
+    0% {
+      background-position: -300% 0;
+    }
+    100% {
+      background-position: 300% 0;
+    }
+  }
+`;