[hobnail]

For the sake of showing another way of styling blockquote, I use a width percentage:

blockquote, div.block {
    margin-left: auto;
    margin-right: auto;
    margin-top: 1em;
    width: 85%;
}

blockquote p, div.block p {
    margin-top: 0.25em;
    text-indent: 0em;
}

blockquote + p, div.block + p {
    margin-top: 1em;
}