Here's a pen: http://codepen.io/JFrankParnell/pen/zxbZZR
<style>
span{ color:red; }
</style>
<span>cant change me</span>
<div>you can change me</div>
If I inspect the <span> with firebug, using the target button, I can see that my
style is color: red, obviously. Normally, I could change color, in
firebug to blue or whatever. Normally, I could click the disable thingy,
in front of the style, to grey it out and it should go back to default
color- no effect. I cant add any other styles to it either, by double clicking and
adding a style. I can change or disable the other element, in
firebug, no prob.