[html] CSS :: child set to change color on parent hover, but changes also when hovered itself

I have an <a> with a <span> children. I have written some CSS which changes the border-color of the children when the parent is hovered, but it also changes the border-color when I hover the children, which it shouldn't.

a {_x000D_
    padding: 50px;_x000D_
    border: 1px solid black;_x000D_
}_x000D_
_x000D_
a span {_x000D_
    position: absolute;_x000D_
    top: 200px;_x000D_
    padding: 30px;_x000D_
    border: 10px solid green;_x000D_
}_x000D_
_x000D_
a:hover span {_x000D_
    border: 10px solid red;_x000D_
}   

<a>_x000D_
    Parent text_x000D_
    <span>Child text</span>    _x000D_
</a>

If you don't care about supporting old browsers, you can use :not() to exclude that element:

.parent:hover span:not(:hover) {
    border: 10px solid red;
}

Demo: http://jsfiddle.net/vz9A9/1/

If you do want to support them, the I guess you'll have to either use JavaScript or override the CSS properties again:

.parent span:hover {
    border: 10px solid green;
}