.bgabout:after { content: ""; position: absolute; top: 0;
    background: url(https://sgmia.vn/uploads/about/bgvn.jpg?1655821245) no-repeat center center;
    height: 100%; width: 100%; z-index: 1; opacity: 0.2;background-size: cover;}

.bgabout > .panel-body{z-index: 2;position: relative;}