.tab button {
    background: transparent;
    border: none;
    margin: 10px;
    display: block;
    font-size: 20px;
    outline: none;
    position: relative;
    transition: 0.3s;
    padding: 10px;
  }
.tab button:before {
    content: '';
    position: absolute;
    width: 0%;
    height: 0.105rem;
    left: 0;
    bottom: 0;
    visibility: hidden;
    background-color: black;
    transition: all 0.3s ease-in-out;
    -webkit-transition: all 0.3s ease-in-out;
    -moz-transition: all 0.3s ease-in-out;
    -ms-transition: all 0.3s ease-in-out;
    -o-transition: all 0.3s ease-in-out;
  }
  .tab button:hover:before {
    width: 100%;
    visibility: visible;
  }
  .tab button.active {
    position: relative;
  }

  .tab button.active::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 0.105rem;
    left: 0;
    bottom: 0;
    background-color: black;
    transition: all 0.3s ease-in-out;
    -webkit-transition: all 0.3s ease-in-out;
    -moz-transition: all 0.3s ease-in-out;
    -ms-transition: all 0.3s ease-in-out;
    -o-transition: all 0.3s ease-in-out;
  }

.tabcontent {
  display: none;
}