var counter=0;

(function waitForISBN() {
  const interval = setInterval(() => {
    const isbnEl = document.querySelector(".sp__the-isbn13");

    if (!isbnEl){
       
return;
    }  // keep waiting

    const isbn = isbnEl.textContent.trim();
    const link = document.querySelector(".wp-block-image.size-full a");

    if (link) {
      link.href = `https://cdcshoppingcart.uchicago.edu/Cart2/ChicagoBook?ISBN=${isbn}&PRESS=wvp`;
      console.log("Cart link updated:", isbn);
    }

    clearInterval(interval); // stop checking once done
  }, 100); // check every 100ms
})();