Seems i dont see the forest while watching so many trees:
I have two divs like:
<div class="show-for-medium"></div>
and
<div class="hide-for-medium"></div>
medium is 600px.
Everything is fine till 599 and from 601, but with 600px i can see both divs.
I tried it with another "display:none" in a media query like
@media only all and (min-width:600px) {
but funny, funny i have the same problem. Seems that min-width:600 means more than 600 and not more or equal 600px.
I am confused and i hope someone can help, please.
What happens if you use
and