    .#{$prefix}mask {
        z-index: 100;
        position: absolute;
        width: 100%;
        height: 100%;
        zoom: 1;
    }

    // The mask is given position: fixed when called on the body.
    // See Element.mask() and EXTJSIV-10726.
    .#{$prefix}mask-fixed {
        position: fixed;
    }

    @if $include-ie {
        .#{$prefix}mask-shim {
            z-index: 100;
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
        }
    }

    .#{$prefix}mask-msg {
        z-index: 20001;
        position: absolute;
    }