构建间隔重复闪卡学习系统

使用 HTML5、CSS3 和 JavaScript 开发一个全面的闪卡学习系统。创建直观的卡片创建和复习界面。实现间隔重复算法，以优化学习效果。支持卡片中的文本、图像和音频。通过卡组和标签对卡片进行分类。实现带有表现跟踪功能的学习会话。添加带有信心等级的自我评估。创建显示学习进度的统计信息面板。支持以标准格式导入和导出卡组。实现键盘快捷键，以便高效复习。添加深色模式和可自定义主题。

Develop a comprehensive flashcard study system using HTML5, CSS3, and JavaScript. Create an intuitive interface for card creation and review. Implement spaced repetition algorithm for optimized learning. Add support for text, images, and audio on cards. Include card categorization with decks and tags. Implement study sessions with performance tracking. Add self-assessment with confidence levels. Create statistics dashboard showing learning progress. Support import/export of card decks in standard formats. Implement keyboard shortcuts for efficient review. Add dark mode and customizable themes.