Seblod templates are just a framework to position various elements in the content (the content element of your default site template).
If you wish to apply different formatting to elements, you can define your styles in default template's custom.css and specify your markup classes in view#3 (for Intro and Content)
If you need a more complex display, you can always try position overrides (for example: templates/seb_one/positions/content_type/intro/mainbody.php)