Anki RTK Kanji<->Keyword on Hover Script

example.js

let mapping = {
  福: "blessing"
};

let element = document.querySelector("pre");
let chars = [...element.innerText];
element.innerHTML = "";

chars.map((char) => {
  if ((/[\u4E00-\u9FAF\uFF66-\uFF9D]/).test(char)) {
    let node = document.createElement("span")
    node.textContent = char
    node.addEventListener("mouseenter", () => {
      node.textContent = mapping[char] || char
    })
    node.addEventListener("mouseleave", () => {
      node.textContent = char
    })
    return node
  } else {
    return document.createTextNode(char)
  }
}).forEach((node) => element.appendChild(node));