body {
    font-family: 'poppins', sans-serif;
    margin: 0;
    padding: 0;
}

#content {
    max-width: 800px;
    margin: 20px auto;
    background-color: #fff;
    border-radius: 10px;
    padding: 20px;
    font-size: 16px;
}

.calculator-manual,
.calculator-content {
    margin-bottom: 20px;
}

.calculator-title {
    font-size: 24px;
    font-weight: bold;
    color: #333;
    margin-bottom: 10px;
}

.calculator-content span {
    display: block;
    margin-bottom: 10px;
    color: #007bff;
    font-weight: 600;
}

.calculator-content .content-bold {
    font-weight: bold;
    color: #333;
}

.future-option {
    display: block;
    margin-bottom: 20px;
}

.future-option a {
    color: #007bff;
    text-decoration: none;
    font-weight: bold;
}

.future-option a:hover {
    text-decoration: underline;
}