.wrapper{
    position: fixed;
    width: 100%;
}
.ballon-banner{
    position: relative;
    z-index: -1;
}
.ballon-banner img{
    position: absolute;
    width: auto;
    height: 128px;
}
.navbar-expand-lg .navbar-nav .nav-link,
.navbar-expand-lg .navbar-nav li * {
    color: aliceblue;
}