style.css

body {
  height: 100%;
}

body {
  margin: 0;
  top:50%;
  /* background-color: #292929; */
  overflow: hidden;
}

nav {
  position: relative;
  top: 5%;
  right: 0;
  left: 0;
  width: 319px;
  display: table;
  margin: 0 auto;
  transform: translateY(-50%);
}

@media screen and (max-width: 768px) {
  nav {
    top: 5%;
    left: -25%;
    display: flex;
    width: 40%;
    flex-direction: row;
    font-size: 10px;
  }
}

nav a {
  position: relative;
  /* width: 33.333%; */
  width: 20%;
  display: table-cell;
  text-align: center;
  color: #949494;
  text-decoration: none;
  font-family: Verdana, Geneva, Tahoma, sans-serif;
  font-weight: bold;
  padding: 10px 20px;
  transition: 0.2s ease color;
}

nav a:before,
nav a:after {
  content: "";
  position: absolute;
  border-radius: 50%;
  transform: scale(0);
  transition: 0.2s ease transform;
}

nav a:before {
  top: 0;
  left: 10px;
  width: 6px;
  height: 6px;
}

nav a:after {
  top: 5px;
  left: 18px;
  width: 4px;
  height: 4px;
}

nav a:nth-child(1):before {
  background-color: yellow;
}

nav a:nth-child(1):after {
  background-color: red;
}

nav a:nth-child(2):before {
  background-color: #00e2ff;
}

nav a:nth-child(2):after {
  background-color: #89ff00;
}

nav a:nth-child(3):before {
  background-color: purple;
}

nav a:nth-child(3):after {
  background-color: palevioletred;
}

nav a:nth-child(4):before {
  background-color: darkgreen;
}


nav a:nth-child(4):after {
  background-color: lightgreen;
}


nav a:nth-child(5):before {
  background-color: darkblue;
}


nav a:nth-child(5):after {
  background-color: lightblue;
}

#indicator {
  position: absolute;
  left: 5%;
  bottom: 0;
  width: 30px;
  height: 3px;
  /* background-color: #fff; */
  border-radius: 5px;
  transition: 0.2s ease left;
}

nav a:hover {
  /* color: #fff; */
}

nav a:hover:before,
nav a:hover:after {
  transform: scale(1);
}

nav a:nth-child(1):hover ~ #indicator {
  background: linear-gradient(130deg, yellow, red);
}

nav a:nth-child(2):hover ~ #indicator {
  left: 28%;
  background: linear-gradient(130deg, #00e2ff, #89ff00);
}

nav a:nth-child(3):hover ~ #indicator {
  left: 49%;
  background: linear-gradient(130deg, purple, palevioletred);
}

nav a:nth-child(4):hover ~ #indicator {
  left: 70%;
  background: linear-gradient(130deg, green, yellow);
}

nav a:nth-child(5):hover ~ #indicator {
  left: 89%;
  background: linear-gradient(130deg, darkblue, lightblue);
}