It looks like you are trying to use css inside your html, but thats not allowed. Only html goes in the html tab, and only css in the css tab. Its best you reset to get everything back to the way it needs to be
Gr8 job. Now add another selector of a div with the width attribute of 300px. A div selector is a type of element not a class name so it does not need to start with a dot.
Ex of type selector: