Ah … tricky … by changing the value of min-width you may inadvertently break other aspects of the media queries and menu system on your or other browsers. I believe that the reason the max-width and min-width are set to adjacent numbers rather than the same number is because the comparison used by CSS is “less than or equal” and “more than or equal” respectively. So, depending on the order in which the media queries are, will depend on which CSS is accepted seeing as when you change the min-width value to 481, both min-width and max-width media queries are true. Bearing in mind these CSS statements determine when and how the nav and other elements of the theme are shown, this could almost certainly have detrimental side effects.
I believe what is happening in your version of Chrome is that rather than returning an integer, a decimal value of the width (larger than 481 but less than 482) is being compared (for whatever reason) which is why neither condition is being met.
Anyway, it’s an old issue that is only located when a specific browser on a specific operating system is specifically forced to 481px wide for which there is already a ticket on trac. I really don’t think this is something to worry or bother about. I certainly wouldn’t make changes to the CSS which may make things worse for all browsers on all operating systems ??
