Listener('keydown', (e) => {
          // Start with Enter/Space even if the hidden input has focus
          if (!state.running && (e.key === 'Enter' || e.key === ' ' || e.code === 'Space')) {
            e.preventDefault();
            requestStart();
            return;
          }
          if (e.key === 'Backspace') { e.preventDefault(); handleBackspace(); return; }
          if (e.key === 'Escape') { togglePause(); return; }
          if (e.key.length === 1 && !e.ctrlKey && !e.metaKey && !e.altKey) {
