export function formatDuration(seconds: number): string {
  const h = Math.floor(seconds / 3600);
  const m = Math.floor((seconds % 3600) / 60);
  const s = seconds % 60;
  return `${h > 0 ? h.toString().padStart(2, '0') + ':' : ''}${m.toString().padStart(2, '0')}:${s.toString().padStart(2, '0')}`;
}