ialog
      function openPdf() {
        localStorage.setItem('product-engineer-manifesto-pdf-downloaded', 'true');
        document.querySelector('dialog').showModal();
      }

      // open dialog if the pdf was downloaded before
      if (localStorage.getItem('product-engineer-manifesto-pdf-downloaded') === 'true') {
        localStorage.removeItem('product-engineer-manifesto-pdf-downloaded');
        document.querySelector('dialog').showModal();
      }

      // close the dialog when clicking outside
