live-football-match-timer/src/css/style.css

https://github.com/PradeepJaiswar/live-football-match-timer

.un:after {
  content: '';
  width: 0px;
  height: 1px;
  display: block;
  background: #ffffff;
  transition: 400ms;
}
.un_transition:after {
  width: 100%;
}