body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f0f0f0;
    margin: 0;
    padding: 0;
}

.container {
    max-width: 800px;
    margin: 20px auto;
    background-color: #ffffff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

h1 {
    text-align: center;
    color: #007BFF;
}

.calculator {
    background-color: #f8f9fa;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.input-group {
    margin-bottom: 15px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    color: #555555;
}

.input-group input[type="number"] {
    width: calc(100% - 80px);
    padding: 8px;
    border: 1px solid #dddddd;
    border-radius: 4px;
    font-size: 16px;
}

.input-group button {
    padding: 8px 12px;
    margin-top: 20px;
    background-color: #007BFF;
    color: #ffffff;
    border: none;
    cursor: pointer;
    border-radius: 4px;
    font-size: 16px;
    transition: background-color 0.3s ease;
}

.input-group button:hover {
    background-color: #0056b3;
}

.output-group {
    margin-top: 20px;
}

.output-group h2 {
    font-size: 1.5rem;
    color: #333333;
}

.output-group #frequencyOutput {
    font-weight: bold;
    font-size: 1.8rem;
    color: #007BFF;
}