How to fix Responsive Issue in IE10 on Windows Phone 8

Here’s what you need to do:
Use @-ms-viewport in your CSS

@-ms-viewport{
width: device-width;
}

Use the meta viewport tag

<meta name="viewport" content="width=device-width, initial-scale=1" />

And finally, in the head section, add the following JavaScript

(function() {
if ("-ms-user-select" in document.documentElement.style && navigator.userAgent.match(/IEMobile\/10\.0/)) {
var msViewportStyle = document.createElement("style");
msViewportStyle.appendChild(
document.createTextNode("@-ms-viewport{width:auto!important}")
);
document.getElementsByTagName("head")[0].appendChild(msViewportStyle);
}
})();

This code specifically targets version IE Mobile 10.0 – also added an extra condition to ensure it only happens in IE – so future, fixed versions will be untouched. It’s worth noting that JavaScript cannot be disabled on Windows Phone 8, so this code will always run.