.weidian {
    margin: 0px auto;
    cursor: pointer;
    background: #fff;
    width: 42px;
    height: 42px;
    -webkit-transition: all ease 0.3s;
    -moz-transition: all ease 0.3s;
    -ms-transition: all ease 0.3s;
    -o-transition: all ease 0.3s;
    transition: all ease 0.3s;
    border-radius: 50%;
    padding: 12px 12px;
  box-shadow: 0 0 4px 2px rgb(255 255 255 / 24%);
}
.weidian:after{
content: '';
    position: fixed;
    background-color: #fff;
    border-radius: 100%;
    transition: all ease .5s;
    top: -36%;
    right: -97%;
    width: 0vw;
    height: 0vw;
}
  }
.weidian.showmenu:after{
content: '';
   width: 300vw;
    height: 300vw;
 
  }
.weidian span {
    width: 100%;
    background: #333;
    display: block;
    height: 2px;
    margin: 2px 0;
    float: left;
    -webkit-transition: all ease 0.8s,opacity ease 0.3s;
    -moz-transition: all ease 0.8s,opacity ease 0.3s;
    -ms-transition: all ease 0.8s,opacity ease 0.3s;
    -o-transition: all ease 0.8s,opacity ease 0.3s;
    transition: all ease 0.8s,opacity ease 0.3s;
    opacity: 1;
}
  .weidian.showmenu{
  padding: 8px 12px;
      background: #111;
  }
.weidian.showmenu span{
  margin: 4px 0;
    background: #000;
  }
.weidian span:nth-of-type(1) {
    width: 50%;
    float: left;
}

.weidian span:nth-of-type(1) {
    width: 50%;
    float: left;
}
.weidian span:nth-of-type(3) {
    width: 50%;
    float: right;
}
.weidian.showmenu {
    animation: showmenu 1s 1;
    -webkit-animation: showmenu 1s 1;
    animation-fill-mode: forwards;
    -webkit-animation-fill-mode: forwards;
  background: #000;
}
.weidian.showmenu span {
    background: #fff;
    -webkit-animation: animaspan 0.5s 1;
    animation: animaspan 0.5s 1;
    animation-fill-mode: forwards;
    -webkit-animation-fill-mode: forwards;
}
.weidian.showmenu span:nth-of-type(1) {
    transform: translateY(10px)rotate(720deg);
    width: 100%;
}
.weidian.showmenu span:nth-of-type(2) {
    transform: rotate(720deg);
}
.weidian.showmenu span:nth-of-type(3) {
    transform: translateY(-10px)rotate(720deg);
    width: 100%;
}
.weidian.showmenu span.biahuan:nth-of-type(1) {
    transform: translateY(10px)rotate(670deg);
}
.weidian.showmenu span.biahuan:nth-of-type(2) {
    transform: translateY(0px)rotate(768deg);
}
.weidian.showmenu span.biahuan:nth-of-type(3) {
    width: 0;
    opacity: 0;
}