.lec-calculator{max-width:400px;margin:20px auto;padding:20px;background:#f8f9fa;border-radius:8px;box-shadow:0 0 10px rgb(0 0 0 / .1);text-align:center}.lec-input-group{margin-bottom:15px;text-align:left}.lec-input-group label{display:block;font-weight:700;margin-bottom:5px}.lec-input-group input,.lec-input-group select{width:100%;padding:10px;border:1px solid #ccc;border-radius:5px}#lec-calculate-btn{width:100%;padding:10px;background:#007bff;color:#fff;border:none;border-radius:5px;cursor:pointer;font-size:16px}#lec-result{display:none;margin-top:15px;padding:15px;background:#e9ecef;border-radius:5px}