console.warn("Demo warning: this page intentionally includes diagnosable issues.");

const longTaskButton = document.querySelector("#long-task");
const taskResult = document.querySelector("#task-result");

longTaskButton.addEventListener("click", () => {
  const start = performance.now();
  while (performance.now() - start < 650) {
    Math.sqrt(Math.random() * Number.MAX_SAFE_INTEGER);
  }
  const duration = Math.round(performance.now() - start);
  taskResult.textContent = `已触发约 ${duration}ms 的主线程长任务。`;
  console.error("Demo error: long task was triggered for DevTools MCP inspection.");
});