If anyone is interested in this, I've come up with a workaround by enclosing the list in a div with padding-left.
Code:
ul, ol {
display: block;
margin: 1em 0 1em 0;
padding-left: 9%;
}
div.ol1d { padding-left:1.16em; } /* for 1 digit list */
div.ol2d { padding-left:1.6em; } /* for 2 digits list */
Code:
<div class="ol1d">
<ol>
<li>Item number is aligned with text-indent of p.</li>
<li>Item.</li>
<li>Item.</li>
</ol>
</div>