Compare these, for instance:
| DOM | style.textDecoration="underline"; |
|---|---|
| CSS | style="text-decoration:underline;" |
| DOM | style.backgroundColor="#ffffcc"; |
| CSS | style="background-color:#ffffcc;" |
| DOM | style.display="none"; |
| CSS | style="display:none;" |
| DOM | style.color="#0000ff"; |
| CSS | style="color:#0000ff;" |
| etc. | |
The same logic is applied whenever we wish to adapt a CSS spec for scripting with DOM.