They will only show if the area to show them in has enough room per say. Basically what Dave said

.
https://developer.mozilla.org/en-US/..._media_queries
http://cssmediaqueries.com/
https://css-tricks.com/snippets/css/...ndard-devices/
Still going huh? Check this question then the replies that followed:
http://stackoverflow.com/questions/4...px-mean-in-css
Make sure you know what you're "looking for" otherwise these may not be the droids you're looking for...

*Translation* make sure you're fixing the style correctly and not adjusting to best fit how you want to view the site... using @media definitions will change how the site looks based on screen size of the device. What you want to avoid is designing the site around YOU and you alone - if its a desktop/pc style then so be it you want what you want but when it comes to mobile/responsive for example, if you style the site to make it look perfect on your ipad mini it might not look perfect on a larger ipad 2 or other tablet. Code for all devices don't conform to one.