*{margin:0;padding:0;box-sizing:border-box}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif;background:linear-gradient(135deg,#667eea,#764ba2);height:100vh}.login-container{display:flex;justify-content:center;align-items:center;height:100vh}.login-box{background:#fff;padding:40px;border-radius:20px;box-shadow:0 20px 60px #0000004d;text-align:center;max-width:400px}.login-box h1{color:#333;margin-bottom:10px}.login-box p{color:#666;margin-bottom:30px}.qr-code{margin:30px 0}.scan-button{background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;border:none;padding:15px 40px;border-radius:10px;cursor:pointer;font-size:16px;transition:transform .2s}.scan-button:hover{transform:scale(1.05)}.chat-container{display:flex;flex-direction:column;height:100vh;background:#fff;max-width:800px;margin:0 auto}.chat-header{background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;padding:20px;display:flex;justify-content:space-between;align-items:center}.chat-header h2{font-size:24px}.user-name{background:#fff3;padding:5px 15px;border-radius:20px;font-size:14px}.messages-container{flex:1;overflow-y:auto;padding:20px;background:#f5f5f5}.message{display:flex;margin-bottom:20px;animation:slideIn .3s ease-out}@keyframes slideIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.avatar{width:40px;height:40px;border-radius:50%;margin-right:10px}.message-content{flex:1;background:#fff;padding:12px 16px;border-radius:12px;box-shadow:0 2px 4px #0000001a}.message-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:5px}.username{font-weight:600;color:#333}.timestamp{font-size:12px;color:#999}.message-text{color:#333;word-wrap:break-word}.message-image{max-width:100%;border-radius:8px;margin-top:8px}.input-container{background:#fff;padding:15px;border-top:1px solid #e0e0e0}.image-preview{display:flex;gap:10px;margin-bottom:10px;flex-wrap:wrap}.preview-item{position:relative;display:inline-block}.preview-item img{width:80px;height:80px;object-fit:cover;border-radius:8px}.preview-item button{position:absolute;top:-8px;right:-8px;background:red;color:#fff;border:none;border-radius:50%;width:24px;height:24px;cursor:pointer;font-size:16px}.input-controls{display:flex;gap:10px;align-items:center}.upload-button{cursor:pointer;font-size:24px;display:flex;align-items:center}.message-input{flex:1;border:1px solid #e0e0e0;border-radius:25px;padding:12px 20px;font-size:16px;outline:none}.message-input:focus{border-color:#667eea}.send-button{background:linear-gradient(135deg,#667eea,#764ba2);color:#fff;border:none;padding:12px 30px;border-radius:25px;cursor:pointer;font-size:16px;transition:transform .2s}.send-button:hover{transform:scale(1.05)}@media (max-width: 768px){.chat-container{max-width:100%}.input-controls{flex-wrap:wrap}.message-input{font-size:16px}}