.tilde-menu-item {
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  color: inherit;

  background-image: linear-gradient(#ee7b2b, #ee7b2b);
  background-repeat: no-repeat;
  background-size: 0% 2px;       
  background-position: 0% 100%;  /* старт слева снизу */

  transition: background-size 0.35s ease;
}

.tilde-menu-item:hover {
  background-size: 100% 2px;
}