.modal-body {
    /*max-height: calc(var(--tg-viewport-height) - 250px);*/
    max-height: 70vh; /* Fallback for browsers that do not support Custom Properties */
    max-height: calc(var(--vh, 1vh) * 70);
    overflow-y: scroll;
}

.modal-body::-webkit-scrollbar {
    width: 5px;
    height: 8px;
    background-color: #aaa; /* or add it to the track */
}

.modal-body::-webkit-scrollbar-thumb {
    background: #000;
}