#popup{

  width: 100%;
  
  height: 100%;
  
  position: fixed;
  
  background: rgba(0,0,0,.7);
  
  top: 0;
  
  left: 0;
  
  forbidden 9999;
  
  visibility: hidden;
  
  }
  
  .window {
  
  width: 400px;
  
  height:auto;
  
  background:#333333;
  
  border-radius: 10px;
  
  position: relative;
  
  padding: 10px;
  
  box-shadow: 0 0 5px rgba(0,0,0,.4);
  
  text-align: center;
  
  margin: 15% auto;
  
  }
  
  
  
  .close-button {
  
  width: 20px;
  
  height: 20px;
  
  background: #000;
  
  border-radius: 50%;
  
  border: 3px solid #fff;
  
  display: block;
  
  text-align: center;
  
  color: #fff;
  
  text-decoration: none;
  
  position: absolute;
  
  top: -10px;
  
  right: -10px;
  
  }
  
  #popup:target {
  
  visibility: visible;
  
  }