Is css necessary?
i mean i been through second chapter and i found that i can do the changes even with HTML5 .. then what's the point?
CSS is for the decoration of the web site
CSS chances the style of your webpage. its up to you to decide if use or not
CSS allows you to make style changes to multiple elements without having to modify each element separately, try creating a more detailed page and compare the value.
using css will help in separating style from actual content... thus making the maintenance of the page simple.
Well, it's not necessary, but without it, your gonna have one horrible website.