[Material UI_ Grid] ❔ window size 구하기 const [windowSize, setWindowSize] = useState(window.innerWidth); const handleWindowResize = useCallback(() => { setWindowSize(window.innerWidth); }, []); window.addEventListener("resize", handleWindowResize); ❔ 컴포넌트 만들기 const ComponentGrid = () => { let colNum = 4; if (windowSize < 1200) colNum = 3; if (windowSize < 900) colNum = 2; if (windowSize < 600) col..