.modalblock {
    display:    none;
    position:   fixed;
    z-index:    1000;
    top:        0;
    left:       0;
    height:     100%;
    width:      100%;
    background: rgba( 255, 255, 255, .6 ) url('/National_Library/oe_/https://www.careflash.com/images/views-v-2/lifetime/loading_1.gif') 50% 50% no-repeat;
}

body.loading {
    overflow: hidden;
}

body.loading .modalblock {
    display: block;
}