.featured-text{
  position: relative;
  display: inline-block;
  padding-bottom: .45em;   /* miejsce na falę */
}

.featured-text .wavey-underline{
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: .6em;            /* wysokość fali */
  display: block;          /* usuwa baseline-inline problem */
  pointer-events: none;
  user-select: none;
}