By Ian Haynes

We can cover a range of device sizes with CSS3 media queries and typically do so using % or ems (or rems) for font sizing and test for the device width in pixels. This can give issues with browser zoom modes however, and a solution is to use ems for the media queries too, rather than pixels, as this blog post by Lyza Gardner explains:

Ian Haynes
Microsoft MVP for Expression Web

Ian is a front end/back end developer currently focusing on HTML5/CSS3 and mobile responsive design. He's a regular poster on the Expression Forums and Gallery.