.full-bg {
    height: 100% !important;
}    

.uc-uchastniky, .uc-sponsor {
    background-color: #34215c !important;
    background-image: url(https://static.tildacdn.com/tild3637-6461-4961-b730-633865373639/hd_fa475cbd9494b3442.jpg) !important;
    background-size: cover !important;
    background-position: center !important;
    background-repeat: no-repeat !important;
    background-attachment: fixed !important; /* ← Параллакс-эффект */
    /* background-blend-mode: luminosity; */
    display: block;
    position: relative;
}