details {
    padding: 10px;
    margin: 10px 0;
    border: 1px solid #cccccc;
    border-radius: 5px;
}

summary {
    font-weight: bold;
    cursor: pointer;
}

summary:hover {
    color: #0000ff;
}

ol {
    margin-left: 2em;
}

ol li {
    list-style-type: none;
    counter-increment: cnt;
}

ol li::before {
    content: counter(cnt) ") ";
}