<h3>Hover Me</h3>

h3 {
  background: linear-gradient(#1095c1 0 0) var(--p,0) 100%/var(--p,0) .1em no-repeat;
  transition: 0.4s, background-position 0s;
}
h3:hover {
  --p: 100%;
}

body {
  height: 100vh;
  margin: 0;
  display: grid;
  grid-template-columns: auto auto;
  gap: 20px;
  place-content: center;
}
h3 {
  font-family: system-ui, sans-serif;
  font-size: 4rem;
  margin: 0;
  cursor: pointer;
  padding: 0 0 .1em;
}