<div style="color: rgb(82, 82, 82);" id="index">index</div>

<script>
  document.addEventListener("DOMContentLoaded", function () {
    var titles = document.querySelectorAll("h1,h2,h3");
    var index = document.getElementById("index");

    for (var i = 0; i < titles.length; i++) {
      if (
        !titles[i].classList.contains("archive__item-title") &&
        !titles[i].classList.contains("author__name") &&
        !titles[i].classList.contains("screen-reader-text")
      ) {
        var tagName = titles[i].tagName;
        titles[i].id = i + "-title";

        if (tagName === "H1") {
          index.innerHTML +=
            "<br> &emsp; -" +
            '<a href="#' +
            i +
            '-title">' +
            titles[i].textContent +
            "</a>";
        } else if (tagName === "H2") {
          index.innerHTML +=
            "<br> &emsp;&emsp; -" +
            '<a href="#' +
            i +
            '-title">' +
            titles[i].textContent +
            "</a>";
        } else if (tagName === "H3") {
          index.innerHTML +=
            "<br> &emsp;&emsp;&emsp; -" +
            '<a href="#' +
            i +
            '-title">' +
            titles[i].textContent +
            "</a>";
        }
      }
    }
  });
</script>