하단 탭바 스크롤 기반 숨김/표시 효과 구현

Facebook 스타일의 스크롤 인터랙션 적용:
- 스크롤 다운 시 탭바 숨김 (translateY + opacity 애니메이션)
- 스크롤 업 시 탭바 표시
- requestAnimationFrame으로 성능 최적화

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/shared/ui/assets/css/style.css

@@ -296,6 +296,11 @@ footer {
     align-items: center;
     z-index: 1000;
     border-top: 0.1px solid var(--color-E5E5E5);
+    transition: transform 0.3s ease-in-out;
+}
+
+.bottom-tabbar.hidden {
+    transform: translateY(100%);
 }
 
 .tab-button {
@@ -308,9 +313,14 @@ footer {
     background: none;
     border: none;
     cursor: pointer;
-    transition: all 0.2s ease;
+    transition: all 0.2s ease, opacity 0.3s ease-in-out;
     padding: 8px 4px;
     box-sizing: border-box;
+    opacity: 1;
+}
+
+.bottom-tabbar.hidden .tab-button {
+    opacity: 0.1;
 }
 
 .tab-button:hover {

src/widgets/navigation/footer.tsx

@@ -15,6 +15,7 @@ export const FooterNavigation = ({
 }: FooterProps) => {
   const { navigate } = useNavigate();
   const [isFooterOn, setIsFooterOn] = useState<boolean>(true);
+  const [isFooterVisible, setIsFooterVisible] = useState<boolean>(true);
 
   const onClickToNavigate = (path?: string) => {
     if(!!path){
@@ -97,39 +98,42 @@ export const FooterNavigation = ({
   };
 
   useEffect(() => {
-    let previousTouch: any;
+    let lastScrollY = 0;
+    let ticking = false;
 
-    const handleTouchStart = (e: TouchEvent) => {
-      const touch: Touch | undefined = e.touches[0];
-      previousTouch = touch;
-    };
-    const handleTouchMove = (e: TouchEvent) => {
-      const touch: Touch | undefined = e.touches[0];
-      let movementY: number | undefined;
-      if(touch && previousTouch){
-        movementY = touch.pageY - previousTouch.pageY;
-        if(movementY > 0){
-          setIsFooterOn(false);
-        }
-        else{
-          setIsFooterOn(true);
-        }
-      };
+    const handleScroll = () => {
+      const currentScrollY = window.scrollY;
+
+      if (!ticking) {
+        window.requestAnimationFrame(() => {
+          // 스크롤 다운 & 일정 거리 이상 스크롤된 경우 -> 숨김
+          if (currentScrollY > lastScrollY && currentScrollY > 50) {
+            setIsFooterVisible(false);
+          }
+          // 스크롤 업 -> 표시
+          else if (currentScrollY < lastScrollY) {
+            setIsFooterVisible(true);
+          }
+
+          lastScrollY = currentScrollY;
+          ticking = false;
+        });
+
+        ticking = true;
+      }
     };
 
-    window.addEventListener('touchstart', handleTouchStart);
-    window.addEventListener('touchmove', handleTouchMove);
+    window.addEventListener('scroll', handleScroll, { passive: true });
 
     return () => {
-      window.removeEventListener('touchstart', handleTouchStart);
-      window.removeEventListener('touchmove', handleTouchMove);
+      window.removeEventListener('scroll', handleScroll);
     };
   }, []);
 
   return (
     <>
       { isFooterOn &&
-        <nav className="bottom-tabbar">
+        <nav className={`bottom-tabbar ${!isFooterVisible ? 'hidden' : ''}`}>
         { getFooterButtonItems() }
         </nav>
       }