let input = iframeDoc.querySelector('pre.edit[contenteditable="true"]')
      await sleep(300)
      await simulateHumanInputAwait(input, "你好")

async function simulateHumanInput(target, value, interval = 80) {
  target.focus()
  target.innerText = ""

  for (let i = 0; i < value.length; i++) {
    const char = value[i]
    target.innerText += char

    // 生成输入事件
    const inputEvent = new InputEvent("input", {
      bubbles: true,
      data: char,
      inputType: "insertText"
    })
    target.dispatchEvent(inputEvent)

    // 键盘事件
    const keyEventDown = new KeyboardEvent("keydown", {
      key: char,
      bubbles: true
    })
    const keyEventUp = new KeyboardEvent("keyup", { key: char, bubbles: true })
    target.dispatchEvent(keyEventDown)
    target.dispatchEvent(keyEventUp)

    await sleep(interval + Math.random() * 30)
  }

  target.blur()
}

pre {
      white-space: pre-wrap; /* 保留格式并自动换行 */
      word-wrap: break-word; /* IE 浏览器兼容 */
      overflow-wrap: break-word; /* 现代浏览器兼容 */
      border: 1px solid #ccc; /* 添加边框便于观察 */
      padding: 10px;
    }