<div class="Tooltip__Container">
  <div class="Tooltip__Target">Target</div>
  <div class="Tooltip__Content" tabindex="0">Content</div>
</div>

<style>
.Tooltip__Container {
  display: inline-block;
  position: relative;
}
.Tooltip__Content {
  position: absolute;
  display: none;
  outline: none;
}

.Tooltip__Container:hover .Tooltip__Content,
.Tooltip__Content:focus,
.Tooltip__Content:focus-within {
  display: block;
}
</style>