import { useEffect, useState } from 'react';/** Whole seconds until `deadline` (epoch ms), ticking once a second. */export function useSecondsLeft(deadline: number): number {const [now, setNow] = useState(Date.now);useEffect(() => {const timer = setInterval(() => setNow(Date.now()), 1000);return () => clearInterval(timer);}, []);return Math.max(0, Math.ceil((deadline - now) / 1000));}