blockquoteでpタグを囲ってblockquoteのpadding-bottom:0px; にするとpタグのmargin-bottomがはみ出す ref: http://qiita.com/items/866

file0.html

<blockquote>
    <p>
    </p>
</blockquote>

file1.css

blockquote {
    padding: {
        top: 0px;
        right: 0px;
        bottom: 0px;
        left: 0px;
    }
}
p {
    margin-bottom: 1.0em;
}

file1.txt

blockquote {
    padding: {
        top: 0px;
        right: 0px;
        bottom: 0px;
        left: 0px;
    }
}
p {
    margin-bottom: 1.0em;
}

file2.css

blockquote {
    padding: {
        top: 0px;
        right: 0px;
        bottom: 1px;
        left: 0px;
    }
}
p {
    margin-bottom: 1.0em;
}

file2.txt

blockquote {
    padding: {
        top: 0px;
        right: 0px;
        bottom: 1px;
        left: 0px;
    }
}
p {
    margin-bottom: 1.0em;
}