*{
    margin: 0;
    padding: 0;
}

body{
    height: 100vh;
    background-color: #000;
    overflow: hidden;
}

canvas{
    width: 100%;
}

#plane{
    color: #fff;
    font-size: 50px;
    position: absolute;
    display: flex;
    justify-content: center;
    align-items: center;
}

.middle{
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.input{
  width: 60px;
  height: 60px;
  background: none;
  border-radius: 50%;
  border: 4px solid #fff;
  box-sizing: border-box;/*限制元素内元素大小不超过设置的宽高*/
  outline: none;
  transition: width 0.4s ease-in-out,
              border-radius 0.8s ease-in-out,
              padding 0.2s;
  transition-delay: 0.4s;
  color: white;
  font-size: 20px;
}

.inclicked{
  width: 500px;
  border-radius: 0;
  padding: 0 15px;
  padding-right: 40px;
}

.btn{
  position: absolute;
  width: 60px;
  height: 60px;
  top: 0;
  right: 0;
  box-sizing: border-box;
  background: none;
  border: none;
  outline: none;
  cursor: pointer;
}

.btn::before{
  content: "";
  width: 4px;
  height: 25px;
  background: white;
  position: absolute;
  transform: rotate(-45deg);
  bottom: -16px;
  right: -6px;
  transition: 0.3s;
}

.close::before,.close::after{
  content: "";
  width: 4px;
  height: 34px;
  background: white;
  position: absolute;
  bottom: 12px;
  right: 28px;
}

.close::before{
  transform: rotate(-45deg);
}

.close::after{
  transform: rotate(45deg);
}