export function relativeTime(input: string): string {
  const timestamp = Date.parse(input);
  if (Number.isNaN(timestamp)) {
    return "now";
  }

  const deltaSeconds = Math.max(0, Math.floor((Date.now() - timestamp) / 1000));
  if (deltaSeconds < 10) return "now";
  if (deltaSeconds < 60) return `${deltaSeconds}s`;

  const deltaMinutes = Math.floor(deltaSeconds / 60);
  if (deltaMinutes < 60) return `${deltaMinutes}m`;

  const deltaHours = Math.floor(deltaMinutes / 60);
  if (deltaHours < 24) return `${deltaHours}h`;

  const deltaDays = Math.floor(deltaHours / 24);
  return `${deltaDays}d`;
}