/* This parent can be any width and height */
.block {
  text-align: center;
}

/* The ghost, nudged to maintain perfect centering */
.block:before {
  content: '';
  display: inline-block;
  height: 100%;
  vertical-align: middle;
  margin-right: -0.25em; /* Adjusts for spacing */
}

/* The element to be centered, can
   also be of any width and height */
.centered {
  display: inline-block;
  vertical-align: middle;
  width: 50%;
}

.father{position:fixed;width:100%;height:100%;top;0;left:0;background-color:rgba(0,0,0,.7);}
.son{position: absolute;top:0;left:0;bottom:0;right:0;width:50%;height:50%;margin:auto;background-color:pink;}

.snowfall-flakes:before{
  content: '';
  position: absolute;
  left: 0px;
  top: 0px;
  width: 20px;
  height: 32px;
  background-color: red;
  border-radius: 10px 10px 0 0;
  transform: rotate(-45deg);

}
.snowfall-flakes:after{
  content: '';
  position: absolute;
  left: 8.6px;
  top: 0px;
  width: 20px;
  height: 32px;
  background-color: red;
  border-radius: 10px 10px 0 0;
  transform: rotate(45deg);
}

.heart{width: 50px;height: 50px;position: fixed;background: #f00;transform: rotate(45deg);-webkit-transform: rotate(45deg);-moz-transform: rotate(45deg);}.heart:after,.heart:before{content: '';width: inherit;height: inherit;background: inherit;border-radius: 50%;-webkit-border-radius: 50%;-moz-border-radius: 50%;position: absolute;}.heart:after{top: -25px;}.heart:before{left: -25px;}