body {
    background: #EFF3FC;
    margin-top: 150px;
}
header {
    top: 0;
    padding: 20px;
    text-align: center;
    position: fixed;
    width: 100%;
    z-index: 3;
}
header .overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(205, 215, 234, 0.4);
    backdrop-filter: blur(5px);
    z-index: -1;
  }
  .nav {
    background: #FFF;
    padding: 10px;
    border-radius: 50px;
  }
  .nav-pills .nav-link {
    padding: 20px;    
    border-radius: 50px;
  }
  .nav-pills .nav-link {
    color: #B1B1B1;
  }
  .nav-pills .nav-link:hover {
    background-color: #00A3FF;
    color: #FFF;
  }
 .nav-pills .nav-link.active,
  .nav-pills .show > .nav-link {
    background-color: #00A3FF;
  }