body { font-family: Arial; background: #f0f2f5; display: flex; justify-content: center; align-items: center; height: 100vh; }
        .container { width: 350px; background: white; padding: 25px; border-radius: 10px; box-shadow: 0 2px 10px rgba(0,0,0,0.1); }
        h2 { text-align: center; color: #333; }
        .form-group { margin-bottom: 15px; }
        label { display: block; margin-bottom: 5px; font-weight: bold; }
        input { width: 100%; padding: 8px; border: 1px solid #ddd; border-radius: 4px; box-sizing: border-box; }
        button { background: #4CAF50; color: white; padding: 10px; border: none; border-radius: 4px; width: 100%; cursor: pointer; }
        .error { background: #f8d7da; color: #721c24; padding: 10px; border-radius: 4px; margin-bottom: 15px; }
        .register-link { text-align: center; margin-top: 15px; }