When you create a page, you can also work directly with HTML. Simply click the “Source” button at the far right in the top tools row. You can create intricate designs and very advanced pages using HTML. However, and this is very important, you must save a copy of your work locally in a text file or email before you click the Submit button to save.
Once you switch between the regular editor mode and Source mode, or when you save, you will not be able to see all of the CSS and HTML when you return to the Source mode. That is why you need a copy of your own, so that you can easily paste it if you want to update something.