h1 {
    text-align: center;
}

h2 {
    font-weight: normal;
}

h3 {
    font-size: 28px;
    text-align: center;
}

.diagram {
    display: block;
    margin: 0 auto;
}

.solution-container {
    max-width: 1000px;
    margin: 0 auto; 
}