* {
    padding: 0;
    margin: 0;
    list-style: none;
    outline: none;
    text-decoration: none;
  }
  body {
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: #f7f7f7;
  }
  body .shell {
    width: 100%;
    position: relative;
    height: auto;
    display: flex;
    flex-direction: column;
    align-items: center;
  }
  body .shell-main {
    width: 100%;
    height: auto;
    position: relative;
    transition: .2s;
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: 100px;
  }

  body .shell-main-nav {
  width: 100%;
  height: 55px;
  position: fixed;
  top: 0;
  z-index: 999;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.5);
  margin-bottom: 18vh;
  background: linear-gradient(to right bottom, rgba(255, 255, 255, 0.8), rgba(255, 255, 255, 0.7), rgba(255, 255, 255, 0.6));
  backdrop-filter: blur(13px);
}
body .shell-main-nav .logo {
  width: 220px;
  height: 100%;
  position: absolute;
  left: 5%;
  justify-content: space-between;
  display: flex;
  align-items: center;
}
body .shell-main-nav .logo img {
  width: 45px;
  height: 45px;
  border-radius: 50%;
}
body .shell-main-nav .logo span {
  font: 100 22px 'font';
  letter-spacing: 2px;
}
body .shell-main-nav ul {
  width: 600px;
  height: 100%;
  display: flex;
  justify-content: space-evenly;
  align-items: center;
  position: absolute;
  right: 5%;
}
body .shell-main-nav span {
  margin-left:42px;
}
body .shell-main-nav ul .nav-box {
  position: absolute;
  bottom: 1px;
  left: 0;
  width: 115px;
  height: 5px;
  border-radius: 2px;
  z-index: -999;
  transition: .5s;
}
body .shell-main-nav ul li {
  width: 150px;
  text-align: center;
}
body .shell-main-nav ul li a {
  color: #000;
  display: block;
  width: 100%;
  height: 100%;
  line-height: 60px;
  text-align: center;
}
body .shell-main-nav ul li a:link{
  color: #000;
}
body .shell-main-nav ul li a:visited{
  color: #66ccff;
}
body .shell-main-nav ul li:nth-child(1):hover~.nav-box {
left: -20px;
background-color: #ee0000;
}
body .shell-main-nav ul li:nth-child(2):hover~.nav-box {
  left: 100px;
  background-color: #ffc839;
}
body .shell-main-nav ul li:nth-child(3):hover~.nav-box {
  left: 220px;
  background-color: #00ffcc;
}
body .shell-main-nav ul li:nth-child(4):hover~.nav-box {
  left: 340px;
  background-color: #66ccff;
}
body .shell-main-nav ul li:nth-child(5):hover~.nav-box {
  left: 460px;
  background-color: #9999ff;
}

@media (max-width:768px) {
  body .shell-main-nav ul {
    transform: scale(.7);
    right: -60px;
    top: 2px;
  }
}
@media (max-width:600px) {
  body .shell-main-nav .logo {
    display: none;
  }
  body .shell-main-nav ul {
    transform: scale(.6);
    right: -120px;
  }
}

@keyframes transform {
  0% {
  transform: rotate(30deg);
  }
  50% {
  transform: rotate(210deg);
  }
  100% {
  transform: rotate(30deg);
  }

}