.nav-menu{
    position: absolute;
    width: 100%;
    top: 0;
    z-index: 15;
    top:0;
    box-shadow: rgba(50, 50, 93, 0.25) 0px 13px 27px -5px, rgba(0, 0, 0, 0.3) 0px 8px 16px -8px;
}
.topnav {
    overflow: hidden;
  }
  
  .topnav a {
    float: left;
    display: block;
    color: #ffffff;
    text-align: center;
    padding: 10px 16px;
    text-decoration: none;
    font-size: 17px;
  }
  
  .activeParent {
    background-color: #372aaf;
  }
  .activeChild {
    background-color: #372aaf;
  }
  
  .topnav .icon {
    display: none;
  }
  
  .dropdown {
    float: left;
    overflow: hidden;
  }
  
  .dropdown .dropbtn {
    font-size: 17px;    
    border: none;
    outline: none;
    color: #ffffff;
    padding: 10px 16px;
    background-color: inherit;
    font-family: inherit;
    margin: 0;
  }
  
  .dropdown-content {
    display: none;
    position: fixed;
    background-color: #4267b2f5;
    min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    z-index: 1;
  }
  
  .dropdown-content a {
    float: none;
    color: white;
    padding: 15px 16px;
    text-decoration: none;
    display: block;
    text-align: left;
  }
  .topnav a:hover, .dropdown:hover .dropbtn {
    background-color: #382aaf;
  }
  
  .dropdown-content a:hover {
    background-color: #382aaf;
  }
  
  .dropdown:hover .dropdown-content {
    display: block;
  }
  /* ---------------------------------------------------screen 800px --------- */
  @media screen and (max-width: 800px) {
    .nav-menu{
      position: fixed;
      background-color: #4267b2;
    }
    .topnav a:not(:first-child), .dropdown .dropbtn {
      display: none;
    }
    .topnav a.icon {
      float: right;
      display: block;
    }
    .topnav.responsive {position: relative;}
    .topnav.responsive .icon {
      position: absolute;
      right: 0;
      top: 0;
    }
    .topnav.responsive a {
      float: none;
      display: block;
      text-align: left;
    }
    .topnav.responsive .dropdown {float: none;}
    .topnav.responsive .dropdown-content {position: relative;}
    .topnav.responsive .dropdown .dropbtn {
      display: block;
      width: 100%;
      text-align: left;
    }
  }