Custom CSS that I use in RCS

RCS-CustomCSS.css

/* Customized RCS CSS by Dazzuh, xBytez and Origin */

/* Background & Color */
.room-background {
    background: url(https://i.xbytez.io/d/ff58a5.png) no-repeat center center fixed !important;
    background-size: cover!important;
    width: 100% !important;
    height: 100% !important;
    top: 0px!important;
    left: 0px!important;
}
#footer,
.app-header,
#history-button,
#rs-skip-button,
#app-menu {
    background: rgba(51, 39, 68, 1)!important
}
#app .app-right, .friends {
    background: transparent!important
}
#chat .cm:nth-child(2n+1),
#chat-input,
#waitlist .list .user {
    background: rgba(51, 39, 65, 1)!important
}
#chat .mention.is-dj:nth-child(2n+1),
#chat .mention.is-staff:nth-child(2n+1),
#chat .mention.is-dj, #chat .mention.is-staff, 
#chat .mention.is-subscriber.silver {
    background: linear-gradient(135deg,#F3508F 0,rgba(51,39,65,1) 13%,rgba(51,39,65,1) 100%)!important
}
#chat .mention.is-ambassador {
    background: linear-gradient(135deg,#89be6c 0,rgba(51,39,65,1) 13%,rgba(51,39,65,1) 100%)
}
#chat .mention.is-admin {
    background: linear-gradient(135deg,#42a5dc 0,rgba(51,39,65,1) 13%,rgba(51,39,65,1) 100%)
}
#audience,
#dj-booth {
    display: none;
}

#chat-button,
#users-button,
#waitlist-button,
#friends-button {
    border-right: transparent
}
.header-panel-button.selected {
    background: linear-gradient(to bottom,rgba(255, 255, 255, 0.25) ,rgba(255, 255, 255, 0.06));
}

#playlist-panel,
#playlist-menu,
#user-view,
#user-menu {
    background: rgba(0,0,0,0.7);
}
.user-content .grid .cell,
.user-content .grid .cell .top,
.user-content .grid .cell:hover>.top {
    background: transparent;
}
.top,
.user-content .grid .cell:hover>.top {
    background: transparent;
}

#rcs-progress-container {
    background-color: rgba(51, 39, 54, 1) !important;
}

#rs-toggle-sidebar {
    background-color: rgba(51, 39, 68, 1) !important;
}

/* Big video */

#playback .background {
    display:none;
}
#playback-controls {
    top: calc(50% - 28px);
    left: calc(50% - 251px) !important;
}
#playback {
    position: fixed !important;
    top: 54px !important;
    bottom: 54px !important;
    left: 0 !important;
    text-align: center;
    white-space: nowrap;
    right: 345px !important;
    display: block !important;
    width: initial !important;
    height: initial !important;
}
#playback:before {
    margin-right: -.25em;
    height: 100%;
    vertical-align: middle;
    display: inline-block;
    content: '';
    box-sizing: border-box;
}

#playback-container, #playback-buffering {
    height: initial !important;
    position: relative !important;
    width: 90% !important;
    vertical-align: middle;
    display: inline-block;
    max-height: 540px;
    max-width: 960px;
}
#playback-container:before, #playback-buffering:before {
    content: "";
    display: block !important;
    padding-top: 56.25% !important;
}
#playback-container #yt-frame, #playback-container #sc-frame, #playback-container #sync-frame {
    position: absolute !important;
    top: 0 !important;
    left: 0 !important;
    bottom: 0 !important;
    right: 0 !important;
    width: 100% !important;
    height: 100% !important;
}

/* Center buttons */

#vote {
    left: initial !important;
    right: calc(20% + 345px);
}

#dj-button {
    left: 20% !important;
}

/* Tiny lists */

#playlist-menu .menu .row {
  height: 24px;
}

#playlist-menu .menu .row .name, #playlist-menu .menu .row .count {
  top: 3px;
  font-size: 12px;
}

#playlist-menu .menu .row .activate-button {
  top: -4px;
}

#waitlist .list .user {
  height: 31px;
}

#waitlist .list .user .meta {
  height: 30px;
}

#waitlist .list .user .name, #waitlist .list .user .position {
  top: 4px;
}

.afkTime {
  top: 6px !important;
}

#waitlist .list .user .icon-drag-handle {
  top: 0px;
}

#waitlist .list .user .image {
  display: none;
}

#user-lists .list .user {
  height: 26px;
}

#user-lists .list .user .name {
  top: 3px;
}

#user-lists .list.room .user i {
  top: 5px;
}

#user-lists .list.room .user i.icon-chat-dj {
  top: 6px;
}

#user-lists .list.room .user .icon-woot {
  top: -3px;
}

.app-right .friends .list .row .image {
  display: none;
}

.app-right .friends .list .row {
  height: 28px;
}

.app-right .friends .list .row .meta {
  top: 3px;
  height: 22px;
}

.app-right .friends .list .row .name {
  margin-left: 5px;
}

.app-right .friends .list .row .meta {
  width: 330px;
}

.app-right .friends .list .row .room {
  width: 160px;
}

/* Chat Fade */

#chat .emote, #chat .mention, #chat .message, #chat .moderation, #chat .skip, #chat .system, #chat .update, #chat .welcome {
  -webkit-animation: fadein 0.35s;
  -moz-animation: fadein 0.35s;
  -ms-animation: fadein 0.35s;
  -o-animation: fadein 0.35s;
  animation: fadein 0.35s;
}

@keyframes fadein {
  from {opacity: 0;};
  to {opacity: 1;};
}

@-moz-keyframes fadein {
  from {opacity: 0;};
  to {opacity: 1;};
}

@-webkit-keyframes fadein {
  from {opacity: 0;};
  to {opacity: 1;};
}

@-ms-keyframes fadein {
  from {opacity: 0;};
  to {opacity: 1;};
}

@-o-keyframes fadein {
  from {opacity: 0;};
  to {opacity: 1;};
}

#user-lists .list {
  -webkit-animation: fadein 0.3s;
  -moz-animation: fadein 0.3s;
  -ms-animation: fadein 0.3s;
  -o-animation: fadein 0.3s;
  animation: fadein 0.3s;
}

#waitlist .list {
  -webkit-animation: fadein 0.3s;
  -moz-animation: fadein 0.3s;
  -ms-animation: fadein 0.3s;
  -o-animation: fadein 0.3s;
  animation: fadein 0.3s;
}