#drop,nav{background-color:#f8f8f8}
.overflow_hidden {
    overflow: hidden;
}

#drop>div,nav,nav~ul{display:flex}
*{font-weight:400;margin:0;padding:0;text-transform:none}
#drop,nav{background-color:#f8f8f8}
nav{
    /* width: 90%; */
    /* height: 100px; */
    /* padding: 0 5%; */
    margin: 0px 0 0 75%;
    position: relative;
    /* top: 2%; */
    justify-content: flex-start;
    z-index: 999999999999;
    align-items: center;
}
nav~ul{position:absolute;flex-direction:column;justify-content:center;align-items:center;left:1%;right:1%;opacity:0;visibility:hidden;z-index:2;list-style:none;transition:0s}
nav~ul>li{color:#70f;padding:10px;cursor:pointer;font-size:26px}
nav~ul>li:hover{filter:brightness(200%)}
nav.open~ul{transition:.75s ease-in-out;visibility:visible;opacity:1}
#drop{cursor: pointer;
    position: fixed;
    width: 60px;
    height: 60px;
    top: 5%;
    border-radius: 50% 50% 50%;
    background: rgba(0,0,0,.6);
    transform: rotate(
45deg
);
/* transition:border-radius .5s */
}
nav.open>#drop{transition:.5s ease-in-out;box-shadow:0 0 0 1000px #f8f8f8,inset 0 0 0 20px #f8f8f8;position:relative}
#drop.active{border-radius:50%;animation:drop .3s forwards}#drop>div{transform:rotate(-45deg);height:100%;width:100%;flex-direction:column;justify-content:center;align-items:center}
#drop span{
    display:block;
    background-color:#70f;
    width:30px;
    height:3px;
    margin:5px 0;
    transition:.5s;
    background: #fff;
}
#drop span.open:nth-child(1){transform:rotate(45deg) translate(5px,5px)}
#drop span.open:nth-child(2){transform:rotate(-45deg) translate(5px,-5px)}
#drop span.open:nth-child(3){opacity:0}
@keyframes drop{0%{transform:translateY(0) rotate(45deg)}50%{transform:translateY(30px) rotate(45deg)}100%{transform:translateY(10px) rotate(45deg)}}
nav.open {
    height: 100px;
}

nav.open~ul {
    overflow: hidden;
    left: 0;
    right: 0;
    background:#f8f8f8;
    width: 100%;
    z-index: 99999999999;
    height: 85%;
}
nav.open>#drop>div {
    background: rgba(0,0,0,.6);
    border-radius: 50%;
}
nav.open>#drop {
    background: none;
    margin-top: 30px;
}
nav.open>#drop span.open:nth-child(3) {
    display: none;
}