// Problema section background — Q clock with rotating hand, sonar rings, ticks function ProblemaBg() { const ref = React.useRef(null); const [visible, setVisible] = React.useState(false); React.useEffect(() => { const observer = new IntersectionObserver( ([entry]) => { if (entry.isIntersecting) { setVisible(true); observer.disconnect(); } }, { threshold: 0.15 } ); if (ref.current) observer.observe(ref.current); return () => observer.disconnect(); }, []); return (

{visible && }

); } window.ProblemaBg = ProblemaBg;