Step 2: Create an External Style Sheet 1. Launch your text editor and create an external style sheet called GPST.css. The file name is case sensitive. 2. Code the stylesheet as follows: a. Global styles for the document (use the body element selector) with a white background (#FFFFFF) and a dark gray text color (#666666) b. Styles for the header element selector that configure the background color to #00B386 and the text color to #FFFFFF. C. Styles for the nav element selector with a background color of #70DBDB. d. Styles for the h2 element selector with a text color of #00664D. e. Styles for the dt element selector that configure the text color as #00664D. f. Styles for a class named barn that will configure the text color as #70DBDB. 3. Save your CSS file in the same folder as the html files for this lab