header {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 1px;
}

header h1 {
    font-size: 44px;
    font-family: 'Times New Roman', Times, serif;
    margin: 0;
    padding: 0;
}

main {
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
    margin-top: 20px;
}

main section {
    width: 300px;
}

.factorials {
    background-color: #f9f9f9;
    padding: 20px;
    border-radius: 8px;
    margin-left: 70px;
    margin-top: 20px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}
.factorials h2 {
    text-align: center;
    color: #333;
}
.factorials form {
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.factorials label {
    font-weight: bold;
}
.factorials input[type="number"] {
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
}
.factorials button {
    padding: 10px;
    background-color: #333;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}
.factorials button:hover {
    background-color: #1a1919;
}
.factorials #factorialResult {
    margin-top: 20px;
    font-size: 1.8em;
    font-weight: bold;
    text-align: center;
    color: #333;
}

.permutation {
    background-color: #f9f9f9;
    padding: 20px;
    border-radius: 8px;
    margin-top: 20px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

.permutation h2 {
    text-align: center;
    color: #333;
}

.permutation form {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.permutation label {
    font-weight: bold;
}

.permutation input[type="number"] {
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
}

.permutation button {
    padding: 10px;
    background-color: #333;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

.permutation button:hover {
    background-color: #1a1919;
}

.permutation #permutationResult {
    margin-top: 20px;
    font-size: 1.8em;
    font-weight: bold;
    text-align: center;
    color: #333;
}

.combination {
    background-color: #f9f9f9;
    padding: 20px;
    border-radius: 8px;
    margin-top: 20px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

.combination h2 {
    text-align: center;
    color: #333;
}

.combination form {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.combination label {
    font-weight: bold;
}

.combination input[type="number"] {
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
}

.combination button {
    padding: 10px;
    background-color: #333;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

.combination button:hover {
    background-color: #1a1919;
}

.combination #combinationResult {
    margin-top: 20px;
    font-size: 1.8em;
    font-weight: bold;
    text-align: center;
    color: #333;
}