�保遮罩层至少显示300ms
            function hideLoadingOverlay() {
               const elapsedTime = Date.now() - startTime;
               const remainingTime = Math.max(0, 300 - elapsedTime);
               
               setTimeout(function() {
                  loadingOverlay.style.opacity = '0';
                  setTimeout(function() {
                     loadingOverlay.style.display = 'none';
                  }, 500); // 等待淡出动画完成后隐藏元素
               }, remainingT