In ASP.NET Gridviews generate a table which generates a parent div container. This can break CSS layouts since there is no way to attach styles to the generated div. Is ther
If you're stuck with an unstyled wrapper (which it appears that you are) but want to enforce a style, give it another wrapper, and apply your style to the combination. If a plain div has some padding you want to get rid of (for example), this in the aspx:
and this for CSS:
div#crushGvDiv, div#crushGvDiv div { padding: 0; margin: 0; }