*{
box-sizing: border-box;
padding: 0;
margin: 0;
}
header{
    width: 100%;
    padding: 10px;
    font-family: Arial, Helvetica, sans-serif;
    background-color: black;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
header ol{
    display: flex;
    justify-content: space-between;
    align-items:center;
    list-style: none;
}
header ol a,header a{
    cursor: pointer;
    color: white;
    text-decoration: none;
}
.logo{
    font-size:28px;
    padding: -6px -22px;
    border-radius: 10px  0px 10px 0px;
     margin: 4px 5px;
    transition:  .3s all ease-in;
}
header ol a li{
    font-size:17px;
    padding: 10px 20px;
    border-radius: 10px  0px 10px 0px;
     margin: 0 5px;
    transition:  .3s all ease-in;
}
header ol a li:hover{
    background-color: white;
    color: black;
}
.checkBtn{
    display: none;
}
        @media only screen and (max-width: 665px) {
    .checkBtn{
      display: block;
     width: 25px;
     height: 25px;
     cursor: pointer;
     position: relative;
     appearance: none;
     -webkit-appearance:  none;
}
.checkBtn::before{
content: '\f0c9';
font-family: 'Font Awesome 5 Free';
font-weight: 700;
font-size: 1.5em;
color: white;
}
.checkBtn:checked::before{
    content: '\f00d';
}

      header ol{
position: absolute;
    width: 100%;
    top: 60px;
    left: 0;
    z-index: 100;
    padding: 1.2em;
    background-color: black;
    flex-direction: column;
    clip-path: polygon(0 0, 100% 0, 100% 0, 0 0);
    transition: .4s clip-path;
}
.checkBtn:checked ~ ol{
    clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
}
 header ol a li{
    margin: 5px 0;
 }
 header ol::before{
    content: '';
    position: absolute;
    width: 100%;
    z-index: 100;
    height: 5px;
    background-color: grey;
    top: 98%;
    left: 0;
 }
}
.logo img{
    height: 32px;
    float: left;
    margin-right: 10px;
  }