Wouldn't CSS be more efficient if it used python syntax (IE no {} but tabs instead)? [on hold]

I was wondering if CSS would be more efficient if it used Python-like formatting (no {} but instead just tabs) and what really goes against converting to that?

Example: The browser could check if the first class it sees in the css is that kind of formatting:

.exampleClass
    color: red;
    background-color: gray;

Otherwise it'd use the default / "legacy" formatting. It could of course also be an even more converted version like

.exampleClass2:
    color = red
    background-color = gray

Or maybe a mixture in between? I'm not sure what would be best/most optimal but I'm quite curious if something like this has been tried and if not, why not?