.water{
    position: absolute;
    left: 50%;
    transform: translate(-50%);
    width: 100vw;
    height: calc(100vw / 2000 * 200);
    /* calc() */
}
.waterwrap{
  transition: all 1s;
  position: absolute;
  /* bottom: calc( 70 / 1920 * 100vw); */
  bottom: calc( 5 / 1920 * 100vw);
  z-index:4;
}
/* .mymove{
    animation: mymove 2s infinite;
    animation-direction:alternate;
    -webkit-animation: mymove 2s infinite;
	-moz-animation: mymove 2s infinite;
	-o-animation: mymove 2s infinite;
	-ms-animation: mymove 2s infinite;
} */
/* @keyframes mymove{
    0%   { transform: rotateZ(0deg);}
    25%  {transform: rotateZ(5deg);}
    50%  {transform: rotateZ(0deg);}
    75%  {transform: rotateZ(-5deg);}
    100% {transform: rotateZ(0deg);}
    100%{ transform: rotateZ(0deg);}
} */