body {
    background-color: #f8f9fa;
    font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
}

.manual-container {
    max-width: 800px;
    margin: 0 auto;
    background-color: #fff;
    padding: 2rem;
    border-radius: 0.5rem;
    box-shadow: 0 0.125rem 0.25rem rgba(0, 0, 0, 0.075);
}

.manual-header {
    margin-bottom: 2rem;
    border-bottom: 1px solid #dee2e6;
    padding-bottom: 1rem;
}

.manual-section {
    margin-bottom: 3rem;
}

.img-placeholder {
    background-color: #e9ecef;
    color: #6c757d;
    display: flex;
    align-items: center;
    justify-content: center;
    height: 200px;
    border: 2px dashed #dee2e6;
    border-radius: 0.25rem;
    margin-bottom: 1rem;
}