Question

My css code:

ol {
    list-style-type: decimal;
}

My HTML code:

<ol>
    <li>This is the first.</li>
    <li>This is the second.</li>
</ol>

my Code is here.

Why they don’t display the leading number?

Answer 1

It’s the fiddle site itself causing it. If you use a DOM inspector on the list nodes, you’ll see that a Fiddle css stylesheet (normalize.css) is overriding your own stylesheet.

If you uncheck the “Normalized CSS” box on the left-hand side of the Fiddle window, the list elements will be numbered as expected.