.lec-calculator {
    max-width: 600px;
    margin: 20px auto;
    padding: 20px;
    background: #f9f9f9;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
    font-family: Arial, sans-serif;
}

.lec-calculator h2 {
    text-align: center;
    color: #333;
    margin-bottom: 20px;
}

.lec-form-group {
    margin-bottom: 15px;
}

.lec-form-group label {
    display: block;
    margin-bottom: 5px;
    color: #555;
    font-weight: bold;
}

.lec-form-group input,
.lec-form-group select {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
}

.lec-form-group input[type="number"] {
    max-width: 70%;
    display: inline-block;
}

.lec-form-group select {
    max-width: 28%;
    margin-left: 2%;
}

.lec-button {
    display: block;
    width: 100%;
    padding: 12px;
    background: #28a745;
    color: #fff;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer;
    transition: background 0.3s;
}

.lec-button:hover {
    background: #218838;
}

#lec-results {
    margin-top: 20px;
    padding: 15px;
    background: #fff;
    border: 1px solid #ddd;
    border-radius: 4px;
}

#lec-results h3 {
    margin-top: 0;
    color: #333;
}

#lec-results p {
    margin: 5px 0;
    color: #555;
}

#lec-error {
    margin-top: 20px;
    padding: 10px;
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
    border-radius: 4px;
    text-align: center;
}

/* FontAwesome icon styling */
.lec-calculator i {
    margin-right: 5px;
}