jitsi-meet/css/_responsive.scss

@media only screen and (max-width: $verySmallScreen) {
    .welcome {
        display: block;

        #enter_room {
            position: relative;
            height: 42px;

            .welcome-page-button {
            font-size: 16px;
            left: 0;
            position: absolute;
            top: 68px;
            text-align: center;
            width: 100%;
            }
        }

        .header {
            background-color: #002637;

            #enter_room {
                .enter-room-input-container {
                    padding-right: 0;
                }

                .warning-without-link,
                .warning-with-link {
                    top: 120px;
                }
            }
        }

        .welcome-tabs {
            display: none;
        }

        .header-text-title {
            text-align: center;
        }

        .welcome-cards-container {
            padding: 0;
        }

        &.without-content {
            .header {
            height: 100%;
            }
        }

        #moderated-meetings {
            display: none;
        }

        .welcome-footer-row-block {
            display: block;
        }
        .welcome-badge {
            margin-right: 16px;
        }

        .welcome-footer {
            display: none;
        }
    }
}

.desktop-browser {
    &.shift-right {

        @media only screen and (max-width: $verySmallScreen + $sidebarWidth) {

            #videoResolutionLabel {
                display: none;
            }
            .vertical-filmstrip .filmstrip {
                display: none;
            }
            .chrome-extension-banner {
                display: none;
            }
        }
    }
}