Internally a lot of editors don't nest inline styles like that. The formatting is more like a style attribute on a <span> tag, listing all style properties. So

Internally a lot of editors don't nest inline styles like that. The formatting is more like a style attribute on a <span> tag, listing all style properties. So you still only have two positions, previous formatting to the left, new formatting to the right. I suspect that is how Bike is doing it.