jitsi-meet/css/filmstrip/_tile_view.scss

/**
 * CSS styles that are specific to the filmstrip that shows the thumbnail tiles.
 */
.tile-view {
    /**
     * Add a border around the active speaker to make the thumbnail easier to
     * see.
     */
    .active-speaker {
        box-shadow: 0 0 5px 3px $videoThumbnailSelected
    }

    #filmstripRemoteVideos {
        align-items: center;
        box-sizing: border-box;
        display: flex;
        flex-direction: column;
        height: 100vh;
        width: 100vw;
    }

    .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%;
    }

    .filmstrip {
        align-items: center;
        display: flex;
        height: 100%;
        justify-content: center;
        left: 0;
        position: fixed;
        top: 0;
        width: 100%;
        z-index: $filmstripVideosZ
    }

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

    #filmstripRemoteVideos {
        box-sizing: border-box;

        /**
         * Allow vertical scrolling of the thumbnails.
         */
        overflow-x: hidden;
        overflow-y: auto;
    }

    /**
     * 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.
     */
    #filmstripRemoteVideosContainer {
        align-content: center;
        align-items: center;
        box-sizing: border-box;
        display: flex;
        flex-wrap: wrap;
        height: 100vh;
        justify-content: center;
        padding: 100px 0;

        .videocontainer {
            border: 0;
            box-sizing: border-box;
            display: block;
            margin: 5px;
        }

        video {
            object-fit: contain;
        }
    }

    .has-overflow#filmstripRemoteVideosContainer {
        align-content: baseline;
    }

    .has-overflow .videocontainer {
        align-self: baseline;
    }

    /**
     * Firefox flex acts a little differently. To make sure the bottom row of
     * thumbnails is not overlapped by the horizontal toolbar, margin is added
     * to the local thumbnail to keep it from the bottom of the screen. It is
     * assumed the local thumbnail will always be on the bottom row.
     */
    .has-overflow #localVideoContainer {
        margin-bottom: 100px !important;
    }
}