Edit in JSFiddle

<details>
<summary>QNimate</summary>
    Narayan Prusty's personal blog.
</details>
details[open] summary
{
    color: red;
    font-size: 20px;
}

details[open]
{
    color: green;
    font-size: 20px;
}

details
{
    -webkit-transition: all 2s; /* For Safari 3.1 to 6.0 */
    transition: all 2s;
}