strapi/docs/1.x.x/en/styles/website.css

li.header{
  color: #101622 !important;
  font-weight: 500;
  letter-spacing: 0.05rem;
}

li.chapter a{
  transition: background-color 0.15s ease;
  -webkit-transition: background-color 0.15s ease;
}

li.chapter:hover a{
  background: #eee !important;
  text-decoration: none !important;
}

.versions-select select{
  height: 36px;
  border: 1px solid #ccc;
}