I’ve got following media-queries rules:
-
@media only screen and (max-width: 854px), only screen and(for devices <= 854px)
(max-device-width: 854px) -
@media only screen and (min-width: 855px), only screen and(for devices > 854px)
(min-device-width: 855px)
It’s strange but Chrome (and may be other browsers) use this rules at the same time (when width is 800px for example) (check screen). What’s wrong?

They are falling back to the same rule because you are using
device-width, the condition fordevice-widthtargets your device’s physical width so if that condition is satisfied then that’s the only rule that will be applied (regardless if you resize your browser to any width). Remove both thedevice-widthconditions from your media queries, this should solve your issue.To learn more about the difference between
device-widthandwidth, refer to this link: http://www.w3.org/TR/css3-mediaqueries/#media1