pma/themes/metro/scss/_list-group.scss

#maincontainer {
  .list-group {
    margin: 1rem 0 0;
    padding-bottom: 10px;
  }

  .list-group-item {
    border: none;
    display: list-item;
    padding: 0;
  }
}

#li_select_server,
#li_change_password,
#li_select_mysql_collation,
#li_user_preferences,
#li_select_lang,
#li_select_theme {
  &.list-group-item {
    display: block;
    padding-top: 10px;
    padding-bottom: 10px;
    padding-right: 10px;
    padding-left: 20px;

    &:hover {
      background: #f6f6f6;
    }
  }
}

#li_select_theme::after {
  content: "Scheme: #{$color-scheme}";
  margin-left: 10px;
}