@media screen and (max-width: 800px) {
    .modalPopup {
        width: 80%; /* The width is 100%, when the viewport is 800px or smaller */
    }
}

.modalBackground {
    background-color: Black;
    filter: alpha(opacity=60);
    opacity: 0.6;
}

.modalPopup {
    background-color: #FFFFFF;
    /*width: 600px;*/
}

    .modalPopup .header {
        background-color: #613813;
        color: White;
        line-height: 30px;
        text-align: center;
        font-weight: bold;
        border-top-left-radius: 6px;
        border-top-right-radius: 6px;
    }

    .modalPopup .body {
        position: relative;
            min-height: 50px;
        line-height: 30px;
        text-align: center;
        font-weight: bold;
    }

    .modalPopup .footer {
        padding: 6px;
    }

    .modalPopup .yes, .modalPopup .no {
        text-align: center;
        font-size: 80%;
    }

    .modalPopup .close-btn {
        top:0px;
        right:0px;
        position:absolute;
    }

    .modalPopup .no {
        background: none !important;
        border: none;
        color: #fff;
        margin-right:6px;
    }