Make Alcatel-Lucent's Rainbow web app use the full width and dark colors.

web.openrainbow.com.user.css

/* ==UserStyle==
@name           Alcatel-Lucent Rainbow, wide and dark
@namespace      github.com/openstyles/stylus
@version        0.1.5
@description    Make Alcatel-Lucent's Rainbow web app use the full width and dark colors.
@author         vctls
==/UserStyle== */
@-moz-document domain("web.openrainbow.com") {
    /* Make the main container use the window full width. */
    .mainArea {
        max-width: unset !important;
    }

    /* Darken everything, remove noise. */
    a:hover,
    .noChannelInfoComponent,
    .mainBackground,
    .mainArea,
    #container,
    #searchArea,
    #resultsArea,
    #stageArea,
    #topArea,
    .topArea,
    #favoriteArea,
    .favoriteZone,
    .userArea,
    #menuArea,
    .navigationChildView,
    .header__card,
    .item--chat,
    .topActionButton,
    .roomInfoContent,
    #conversationTitle,
    #inviteContacts,
    #footer,
    .header,
    .container,
    #emojisContainer,
    .emojiSelect,
    .convAreaComponent,
    .conv-panel,
    .chatControls,
    .tabContent,
    .tabs5,
    .tabsHeader,
    .tab,
    .channelDiscoverMain,
    .convAreaContent__rightView--title,
    .userListCell,
    .home__aside,
    .ui__card,
    .documentDetails__actions,
    .documents-details__footer,
    .document-cell__wrapper,
    .document-cell__preview,
    .document-cell__label,
    .divider,
    .windowContent,
    .windowHeader,
    .windowFooter,
    .windowEndUserComponentFooter,
    .slider {
        background: #111 !important;
        box-shadow: unset !important;
        border: unset !important;
        border-radius: unset !important;
    }

    /* Remove that useless bottom space. */
    .mainArea {
        height: 100% !important;
    }

    .textarea-container,
    #chattextarea,
    #bubble,
    .searchContainer,
    .searchInput,
    .channel__search-filter,
    .tabSel,
    .tabPanel,
    .groupsMng,
    .topAreaStatusList,
    .value,
    .dropdown-menu,
    .detailsSection,
    .documents__header,
    .documents__thumbnails,
    .topActionButtonSel,
    .noCalllog,
    .calllogs__content,
    .smallerUserArea,
    .usersAreaNoContent,
    .user-details__avatar,
    #telContainer,
    .tags {
        background-color: #373737 !important;
        color: #ddd !important;
        border: unset !important;
    }
    
    .input {
        background-color: unset !important;
        color: #ddd !important;
    }

    /* Squeeze conference header */
    .item--call-audio,
    .conversation-info__name {
        flex: unset !important;
        height: 56px !important;
        max-height: unset !important;
        min-height: unset !important;
        margin: 0 !important;
    }

    .channelSlideMask,
    .ui__diagonal::before,
    .dropdown-topUser::after,
    .audio-container__avatar,
    .noChannelInfoComponent > img:nth-child(5) {
        display: none;
    }

    /* Dim colorful content a bit. */
    .userAvatar,
    .roomAvatar,
    .chatModuleAvatar,
    .bubble,
    .topActionIcon {
        filter: brightness(90%);
    }

    /* Use the more legible fallback font as default. */
    body {
        font-family: Helvetica Neue, Helvetica, Arial, sans-serif !important;
    }
}