owncast/web/components/ui/Sidebar/Sidebar.module.scss

.root {
  background-color: var(--theme-color-components-chat-background);
  display: none;
  --header-h: 64px;
}

@media (min-width: 768px) {
  .root {
    position: sticky;
    top: var(--header-h);
    display: block;
    height: calc(100vh - var(--header-h));
    max-height: calc(100vh - var(--header-h));
  }
}
/*
First div is .ant-layout-sider-children
Only way to target it apparently
*/
.root > div {
  display: flex;
  flex-flow: column nowrap;
  -moz-box-flex: 1 !important;
  flex-grow: 1 !important;
  height: 100% !important;
}