.wp-bing-search-tab {
  display: inline-block;
  margin-bottom: 10px;
}

a.active-wp-bing-search-tab,
a.wp-bing-search-tab:focus,
a.wp-bing-search-tab:hover,
a.wp-bing-search-tab:active {
  border-bottom: 2px solid;
  text-decoration: none;
  outline: none;
}