如何将类添加到第一个段落并跨越到第一个字母

Example

<p>Lorem ipsum dolor sit amet</p>
<p>Morbi elementum odio vel tortor adipiscing vel tempor risus ullamcorper.</p>

I want add class for first paragraph and add span class to the first letter

<p class="first-paragraph"><span class="first-letter">L</span>orem ipsum dolor sit amet</p>

Let me know how can be with PHP

$text = '<p>Lorem ipsum dolor sit amet</p>
<p>Morbi elementum odio vel tortor adipiscing vel tempor risus ullamcorper.</p>';

$text = substr_replace($text, '</span>', 4, 0);
$text = substr_replace($text, '<span class="first-letter">', 3, 0);
$text = substr_replace($text, ' class="first-paragraph"', 2, 0);

echo htmlspecialchars($text);

:-)

You can make use of pure CSS3:

p:first-of-type {
    color: red; 
}

p:first-of-type::first-letter {
    color: blue;
    font-size: x-large;
}

fiddle here: http://jsfiddle.net/everton/vpcey/