         if (isInitial) {
                showLoadingOverlay();
            }

            const frameId = `slideFrame_${frameIdCounter++}`;
            const iframe = document.createElement('iframe');
            iframe.id = frameId;
            iframe.className = 'slide-frame hidden not-loaded';
            iframe.title = `PPT Slide ${index + 1}`;

            // 设置内容
            if (slidesData[index] && slidesData[index].html_content) {
                iframe.srcdoc = slidesData[index].html_conte