* {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
  font-weight: 300;
}
body {

  font-family: "Microsoft YaHei", sans-serif;
}
body.nav-open .lower-screen {
  -webkit-transform: scale(0.8, 0.8);
      -ms-transform: scale(0.8, 0.8);
          transform: scale(0.8, 0.8);
}
body.nav-open .nav {
  -webkit-transform: translateY(0);
  transform: translateY(0);
}
body.nav-open .nav-toggle {
  box-shadow: none;
}
body.nav-open .nav-toggle:before {
  width: 1200px;
  height: 1200px;
  background-color: rgba(65, 65, 65, 0.75);
}
body.nav-open .nav-toggle .icon {
  width: 0;
}
body.nav-open .nav-toggle .icon:before {
  -webkit-transform: translateY(9px) rotate(45deg);
      -ms-transform: translateY(9px) rotate(45deg);
          transform: translateY(9px) rotate(45deg);
}
body.nav-open .nav-toggle .icon:after {
  -webkit-transform: translateY(-9px) rotate(-45deg);
      -ms-transform: translateY(-9px) rotate(-45deg);
          transform: translateY(-9px) rotate(-45deg);
		  z-index:5
}



.nav-toggle {
  width: 60px;
  height: 60px;
  z-index: 2;
  right:0px;

  border-radius: 50%;
  margin:0px 10px;
  position: fixed;
  cursor: pointer;
  -webkit-transition-duration: 0.66s;
          transition-duration: 0.66s;
  -webkit-transition-timing-function: swing;
          transition-timing-function: swing;
}
.nav-toggle:before {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  content: "";
  position: absolute;
	
  left: 50%;
  -webkit-transform: translateX(-50%) translateY(-50%);
      -ms-transform: translateX(-50%) translateY(-50%);
          transform: translateX(-50%) translateY(-50%);
  -webkit-transition-duration: 0.66s;
          transition-duration: 0.66s;
  -webkit-transition-timing-function: swing;
          transition-timing-function: swing;
}
.nav-toggle .icon {
  width: 30px;
  height: 4px;
  background-color: #333;
  border-radius: 2px;
  position: absolute;
  top: 28px;
  left: 15px;
  -webkit-transition-duration: 0.5s;
          transition-duration: 0.5s;
  transiting-timing-function: swing;
}
.nav-toggle .icon:before,
.nav-toggle .icon:after {
  width: 30px;
  height: 4px;
  background-color:#333;
  border-radius: 2px;
  content: "";
  position: absolute;
  left: 0;
  -webkit-transition-duration: 0.5s;
          transition-duration: 0.5s;
  -webkit-transition-timing-function: swing;
  transition-timing-function: swing;
}
.nav-toggle .icon:before {
  top: -9px;
}
.nav-toggle .icon:after {
  top: 9px;
}

.nav {
  position: fixed;
  top: 80px;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 9;
  padding: 0 20px;
  -webkit-transition-duration: 0.66s;
          transition-duration: 0.66s;
  -webkit-transition-timing-function: swing;
          transition-timing-function: swing;
  -webkit-transform: translateY(100%);
          transform: translateY(100%);
}
.nav ul li {
  list-style: none;
}
.nav ul li a {
  display: block;
  padding: 10px 0;
  text-align: center;
  color: white;
  text-decoration: none;
  font-size: 20px;
  -webkit-transition-duration: 0.25s;
          transition-duration: 0.25s;
}
.nav ul:hover li a {
  opacity: 0.5;
}
.nav ul:hover li:hover a {
  opacity: 1;
}