matrix-dimension/web/app/widget_wrappers/generic/generic.component.scss

// component styles are encapsulated and only applied to their components
.control-page {
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  margin: 0;
  padding: 0;
  background-color: #222;
  color: #eee;
}

.loading-badge {
  text-align: center;
  font-size: 20px;
  position: relative;
  top: calc(50% - 10px);
}

.embed-failed {
  text-align: center;
  position: relative;
  height: 300px;
  top: calc(50% - 150px);
}

.embed-failed .ban {
  font-size: 145px;
  color: #bd362f;
}

iframe {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  right: 0;
  width: 100%;
  height: 100%;
}

.toggleFullscreen {
  position: fixed;
  bottom: 10px;
  right: 10px;
}