Update
This answer is outdated. You can do this a lot more simply, as pointed out in another answer below:
ul {
list-style-position: outside;
}
See https://www.w3schools.com/cssref/pr_list-style-position.asp
Original Answer
I’m surprised to see this hasn’t been solved yet. You can make use of the browser’s table layout algorithm (without using tables) like this:
ol {
counter-reset: foo;
display: table;
}
ol > li {
counter-increment: foo;
display: table-row;
}
ol > li::before {
content: counter(foo) ".";
display: table-cell; /* aha! */
text-align: right;
}
Demo: http://jsfiddle.net/4rnNK/1/
To make it work in IE8, use the legacy :before
notation with one colon.