#crt {
    background-image: url('pixel.apng');
    background-size: 2px 1px;
    background-color: #fff;
    background-blend-mode: hard-light;
    mix-blend-mode: multiply;
    pointer-events: none;
    opacity: .4
}

#crt {
    position: fixed;
    width: 100%;
    top: 0;
    bottom: 0;
    right: 0;
    left: 0;
    z-index: 9999
}

@-moz-document url-prefix() {
    #crt {
        opacity: .1
    }
}