#rule-of-72-form{max-width:400px;margin:0 auto;padding:20px;border:1px solid #ccc;border-radius:8px;background-color:#f9f9f9;box-shadow:0 0 10px rgb(0 0 0 / .1)}#rule-of-72-form label{display:block;margin-bottom:8px}#rule-of-72-form input[type=number]{width:100%;padding:10px;font-size:16px;border:1px solid #ccc;border-radius:4px;box-sizing:border-box;margin-bottom:10px}#rule-of-72-form button{width:100%;padding:10px;font-size:16px;color:#fff;background-color:#007bff;border:none;border-radius:4px;cursor:pointer;box-sizing:border-box;margin-top:10px;transition:background-color .3s ease}#rule-of-72-form button:hover{background-color:#0056b3}.result-box{padding:20px;margin-top:20px;border:1px solid #007bff;border-radius:8px;background-color:#e9f5ff;text-align:center;box-shadow:0 0 10px rgb(0 0 0 / .1)}.result{font-size:24px;font-weight:700;margin:0;color:#007bff}.explanation{font-size:14px;color:#555;margin:10px 0 0}@media (max-width:600px){#rule-of-72-form{padding:15px}#rule-of-72-form button{font-size:14px;padding:8px}#rule-of-72-form input[type=number]{font-size:14px;padding:6px}.result{font-size:20px}}