abbr {
  color: var(--muted);
  text-decoration: underline dotted;
}

abbr[title],
abbr[data-title] {
  position: relative;
  color: var(--accent);
  cursor: help;
}

abbr[data-title]::after {
  position: absolute;
  top: -125%;
  left: 50%;
  display: none;
  padding: 0.5em;
  border: 1px solid var(--bd-muted);
  border-radius: var(--bd-radius);
  background: var(--bg-muted);
  box-shadow: var(--shadow);
  color: var(--default);
  content: attr(data-title);
  font-size: 0.75em;
  opacity: 0;
  pointer-events: none;
  transform: translateX(-50%);
  transition: opacity var(--tr-duration);
  white-space: nowrap;
}

abbr[data-title]:hover::after {
  display: block;
  opacity: 1;
}