.app{max-width:800px;margin:0 auto;padding:20px}header{text-align:center;margin-bottom:30px}header h1{font-size:2rem;color:#333}header p{color:#666;margin-top:5px}.tabs{display:flex;gap:10px;margin-bottom:20px;border-bottom:2px solid #ddd;padding-bottom:10px}.tabs button{flex:1;padding:12px;border:none;background:#f0f0f0;border-radius:8px 8px 0 0;cursor:pointer;font-size:1rem;transition:all .2s}.tabs button:hover{background:#e0e0e0}.tabs button.active{background:#4a90d9;color:#fff}.content{background:#fff;border-radius:12px;padding:20px;box-shadow:0 2px 10px #0000001a}.upload-section{text-align:center}.upload-box{border:3px dashed #ccc;border-radius:12px;padding:40px;margin-bottom:20px}.upload-box input{display:none}.upload-box label{display:block;cursor:pointer;font-size:1.1rem;color:#666}.upload-box label:hover{color:#4a90d9}.files-list{text-align:left;margin-top:20px}.files-list h3{margin-bottom:10px;color:#333}.files-list ul{list-style:none}.files-list li{padding:10px;background:#f9f9f9;border-radius:6px;margin-bottom:5px}.chat-section{display:flex;flex-direction:column;height:400px}.chat-messages{flex:1;overflow-y:auto;padding:10px;border:1px solid #eee;border-radius:8px;margin-bottom:10px}.message{margin-bottom:15px;padding:10px;border-radius:8px}.message.user{background:#e3f2fd;margin-left:20%}.message.assistant{background:#f5f5f5;margin-right:20%}.message strong{display:block;margin-bottom:5px}.empty{text-align:center;color:#999;padding:40px}.loading{text-align:center;color:#4a90d9}.chat-input{display:flex;gap:10px}.chat-input input{flex:1;padding:12px;border:1px solid #ddd;border-radius:8px;font-size:1rem}.chat-input button{padding:12px 24px;background:#4a90d9;color:#fff;border:none;border-radius:8px;cursor:pointer;font-size:1rem}.chat-input button:hover{background:#357abd}.chat-input button:disabled{background:#ccc;cursor:not-allowed}.exam-section{text-align:center}.exam-input{display:flex;gap:10px;margin-bottom:20px}.exam-input input{flex:1;padding:12px;border:1px solid #ddd;border-radius:8px;font-size:1rem}.exam-input button{padding:12px 24px;background:#4caf50;color:#fff;border:none;border-radius:8px;cursor:pointer;font-size:1rem}.exam-input button:hover{background:#43a047}.exam-input button:disabled{background:#ccc;cursor:not-allowed}.exam-result{text-align:left;margin-top:20px}.exam-result h3{margin-bottom:10px}.exam-result pre{background:#f9f9f9;padding:15px;border-radius:8px;white-space:pre-wrap;font-family:inherit}