function loadTracks() {
  return new Promise((resolve) => {
    setTimeout(() => {
      resolve(["模板字符串", "模块化", "async/await"]);
    }, 700);
  });
}

// 任务：
// 1. 调用 loadTracks()
// 2. 成功时更新状态和输出内容
// 3. 失败时更新状态
async function load() {
  const status = document.getElementById("status")
  status.textContent = "加载中"
  try {
    const a = await loadTracks()
    status.textContent = "加载成功"
    const output = document.getElementById("output")
    output.textContent = a
  } catch (error) {
    status.textContent = "加载失败"
  }

}
load()