描述一个闪卡学习应用：间隔重复算法、图文音卡片、牌组与标签、学习表现追踪。
使用 HTML5、CSS3 和 JavaScript 开发一套全面的闪卡学习系统。创建直观的卡片创建与复习界面。实现间隔重复算法以优化学习效果。为卡片添加对文本、图像和音频的支持。支持通过牌组（decks）和标签（tags）对卡片进行分类。实现带有学习表现追踪功能的学习会话。添加基于信心等级的自我评估功能。创建统计信息仪表板，展示学习进度。支持以标准格式导入/导出卡片牌组。为高效复习实现键盘快捷键。添加深色模式及可自定义的主题。
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.