.BT-all {
    position: fixed;
    z-index: 9950;}
.B11 {
    position: absolute;
    display: block;
    width: 200px; height: 400px;
    opacity: 1;
    top: -1000px; 
    left: -10px;
    z-index: 9950;
}
.B12 {
    position: relative;
    display: block;
    width: 200px; height: 400px;
    opacity: 1;
    top: -1000px; 
    right: -200px;
    transform: scaleX(-1);
    z-index: 9950;
}