1 - fonction de «bionic reading»
const e = document.getElementById("edit"), r = document.getElementById("read");
const u = () => r.innerHTML = e.innerHTML.split(" ").map(w => `<b>${w.split("").slice(0,Math.ceil(w.length/2)).join("")}</b>${w.split("").slice(Math.ceil(w.length / 2),w.length).join("")} `).join(" ");
u();
e.addEventListener("input", u);

/* kodun orjinal halini de bırakayım da belki birinin işine yarar
const editor = document.getElementById("edit");
const reader = document.getElementById("read");

const updateContent = (e) => {
  const words = editor.innerHTML.split(" ");
  const edited = [];
  words.forEach((word, index) => {
    const wordSplit = word.split("");
    const boldTo = Math.ceil(word.length / 2);
    const editedWord = `<b>${wordSplit.slice(0,boldTo).join("")}</b>${wordSplit.slice(boldTo,word.length).join("")} `;
    edited.push(editedWord);
  });
  reader.innerHTML = edited.join("");
}

(() => {
  updateContent(); // init
  editor.addEventListener("input", updateContent);
})()
*/