.calculator{border:1px solid #ccc;padding:20px;margin-bottom:20px;font-family:sans-serif;background-color:#f9f9f9}.calculator h3{margin-top:0;color:#333}.calculator label{display:block;margin-bottom:5px;font-weight:bold}.calculator input[type="number"],.calculator input[type="text"]{width:100%;padding:8px;margin-bottom:10px;box-sizing:border-box;border:1px solid #ccc}.calculator button{background-color:var(--primary-color,#007bff);color:#fff;padding:10px 15px;border:none;cursor:pointer;transition:background-color .3s ease}.calculator button:hover{background-color:#0056b3}.calculator .error{color:red;font-weight:bold;margin-bottom:10px}.calculator-results p{margin:5px 0}.calculator-results strong{display:inline-block;width:150px}