.nav {
  display: -webkit-inline-box;
  display: inline-flex;
  position: relative;  
  overflow: hidden;
  max-width: 100%;
  background-color: #fff;
  padding: 0 20px;
  border-bottom: 6px solid lightgray;
  width: 100%;
  <!-- box-shadow: 0 10px 40px rgba(159, 162, 177, 0.8); -->

}

.nav-item {
  color: #83818c;
  padding: 10px;
  text-decoration: none;
  <!-- -webkit-transition: .8s; -->
  <!-- transition: .3s; -->
  margin: 0 6px;
  font-family: 'DM Sans', sans-serif;
  font-size: 20px; 
  font-weight: 600;
  position: relative;
  width: 50%;
  text-align: center;

}
.nav-item:before {
  content: "";
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 100%;
  height: 5px;
  background-color: #dfe2ea;
  border-radius: 0px 0px 0 0;
  <!-- border-radius: 8px 8px 0 0; - rounded selector -->
  opacity: 0;
 <!--  -webkit-transition: .3s; -->
  <!-- transition: .3s; -->

}

.nav-item:not(.is-active):hover:before {
  opacity: 1;
  bottom: 0;
}

.nav-item:not(.is-active):hover {
  color: #333;
}

.nav-indicator {
  position: absolute;
  left: 0;
  bottom: 0;
  height: 4px;
  -webkit-transition: .4s;
  <!--  transition: .4s; -->
  height: 5px;
  border-radius: 0px 0px 0 0;
  <!-- border-radius: 8px 8px 0 0; - rounded selector -->
}