Browser not recognizing max-device-width

Question

I am implementing responsive web design for my site. For that I am using @media queries for displaying different views on different devices. For testing purpose I am using web developer toolbar for firefox and responsive site view add-on for google chrome.

However if I am using :

@media only screen and (max-device-width: 480px)
{
    //CSS
}

Then its working on actual device but not in browser

and

If I am using

@media only screen and (max-width: 480px)
{
    //CSS
}

Then its only working on browser and not in device.

Where I am going wrong? Need Help

Answer 1

@media only screen 
    and (min-device-width : 320px) 
    and (min-width : 320px) {
    /* Styles */
    } 

doesn't work in Firefox OS simulator.

Answer 2

In your case you can use like this

@media only screen 
    and (min-device-width : 320px) 
    and (min-width : 320px) {
    /* Styles */
    }

and this is a slandered media queries code for all devices by Chris Coyier

/* Smartphones (portrait and landscape) ----------- */
@media only screen 
and (min-device-width : 320px) 
and (max-device-width : 480px) {
/* Styles */
}

/* Smartphones (landscape) ----------- */
@media only screen 
and (min-width : 321px) {
/* Styles */
}

/* Smartphones (portrait) ----------- */
@media only screen 
and (max-width : 320px) {
/* Styles */
}

/* iPads (portrait and landscape) ----------- */
@media only screen 
and (min-device-width : 768px) 
and (max-device-width : 1024px) {
/* Styles */
}

/* iPads (landscape) ----------- */
@media only screen 
and (min-device-width : 768px) 
and (max-device-width : 1024px) 
and (orientation : landscape) {
/* Styles */
}

/* iPads (portrait) ----------- */
@media only screen 
and (min-device-width : 768px) 
and (max-device-width : 1024px) 
and (orientation : portrait) {
/* Styles */
}

/* Desktops and laptops ----------- */
@media only screen 
and (min-width : 1224px) {
/* Styles */
}

/* Large screens ----------- */
@media only screen 
and (min-width : 1824px) {
/* Styles */
}

/* iPhone 4 ----------- */
@media
only screen and (-webkit-min-device-pixel-ratio : 1.5),
only screen and (min-device-pixel-ratio : 1.5) {
/* Styles */
}