Margin, border, and padding as you see in the picture, are all situated around the content. You can designate the size and style of these in your style sheet.
The following is an example of how you can do this.
padding: 100px; or 10px 20px; or all four sides
border-style: solid; of border-bottom-style: solid
or border: solid black 10px;(for all encompassing)
outline: 1px solid red; (around border)