.chat-viewport {
    height: calc(100vh - 60px);
    /* Высота под ваш хедер */
}

@media (min-width: 992px) {
    .offcanvas-lg {
        position: static !important;
        visibility: visible !important;
        transform: none !important;
        display: flex !important;
    }
}

.chat-scroll {
    overflow-y: auto;
    min-height: 0;
}

.chat-selected-dialog{
    border-left: 4px solid var(--bs-primary) !important;
}