CSS/Selectors/pseudo-classes/:first-of-type
From W3C Wiki
Pseudo-class :first-of-type
The :first-of-type pseudo-class represents an element that is the first sibling of its type in the list of children of its parent element. Same as :nth-of-type(1).
Syntax
selector:first-of-type{ properties }
Example
It is a valid description for the first two dt elements in the following example but not for the third one:
[style.css]
dl dt:first-of-type{ color: red; }
[index.html]
<body> <dl> <dt>gigogne</dt> <dd> <dl> <dt>fusée</dt> <dd>multistage rocket</dd> <dt>table</dt> <dd>nest of tables</dd> </dl> </dd> </dl> </body>
CSS defines the :first-of-type pseudo-class selector in 6.6.5.8. :first-of-type pseudo-class.