jitsi-meet/css/filmstrip/_tile_view.scss

/**
 * CSS styles that are specific to the filmstrip that shows the thumbnail tiles.
 */
.tile-view {

    .remote-videos {
        align-items: center;
        box-sizing: border-box;
        display: flex;
        flex-direction: column;
        overscroll-behavior: contain;
    }

    .filmstrip__videos .videocontainer {
        &:not(.active-speaker),
        &:hover:not(.active-speaker) {
            border: none;
            box-shadow: none;
        }
    }

    #remoteVideos {
        /**
         * Height is modified with an inline style in horizontal filmstrip mode
         * so !important is used to override that.
         */
        height: 100% !important;
        width: 100%;
        display: flex;
        justify-content: center;
        align-items: center;
        transition: margin-bottom .3s ease-in;
    }

    .filmstrip {
        align-items: center;
        display: flex;
        height: 100%;
        justify-content: center;
        left: 0;
        position: absolute;
        top: 0;
        width: 100%;

        @media (min-width: 581px) {
            &.shift-right {
                margin-left: $sidebarWidth;
                width: calc(100% - #{$sidebarWidth});

                .remote-videos {
                    width: calc(100vw - #{$sidebarWidth});
                }
            }
        }

        &.collapse {
            #remoteVideos {
                height: calc(100% - #{$newToolbarSizeMobile}) !important;
                margin-bottom: $newToolbarSizeMobile;
            }

            .remote-videos {
                // !important is needed here as overflow is set via element.style in a FixedSizeGrid.
                overflow: hidden auto !important;
            }
        }
    }

    /**
     * Regardless of the user setting, do not let the filmstrip be in a hidden
     * state.
     */
    .filmstrip__videos.hidden {
        display: block;
    }

    .remote-videos {
        box-sizing: border-box;


        /**
        * The size of the thumbnails should be set with javascript, based on
        * desired column count and window width. The rows are created using flex
        * and allowing the thumbnails to wrap.
        */
        & > div {
            align-content: center;
            align-items: center;
            box-sizing: border-box;
            display: flex;
            margin-top: auto;
            margin-bottom: auto;
            justify-content: center;
            position: absolute;

            .videocontainer {
                border: 0;
                box-sizing: border-box;
                display: block;
                margin: 2px;
            }

            video {
                object-fit: contain;
            }

            /**
            * Max-width corresponding to the ASPECT_RATIO_BREAKPOINT from features/filmstrip/constants.
            */
            @media only screen and (max-width: 500px) {
                video {
                    object-fit: cover;
                }
            }
        }
    }
}

.shift-right .remote-videos > div {
    /**
     * Max-width corresponding to the ASPECT_RATIO_BREAKPOINT from features/filmstrip/constants,
     * from which we subtract the chat size.
     */
    @media only screen and (max-width: calc(500px + #{$sidebarWidth})) {
        video {
            object-fit: cover;
        }
    }
}