body {
  /*position:absolute;*/
  z-index:0; 
  /*border:1px solid black; */
  /*left:5%; */
  /*top:5%; */
  width:100%; 
  height:100%;
  background: black;
}

.game_menu {
  margin: 150px auto 0;
  width: 300px;
  height: 100px;
  position: relative;
}

.game_menu ul {
  list-style: none;
  border: 2px solid yellow;
}

.game_menu ul li {
  border: 3px solid yellow;
  text-align: center;
  margin: 2px;
}

.game_menu ul li a {
  color: yellow;
  font-weight: bold;
  padding: 5px 0;
  display: block;
}

.game_menu ul li:hover {
  border-color: green;
}
.game_menu ul li:hover a {
  color: green;
}

.svg {
  width:100%; 
  height:100%; 
  position:absolute; 
  top:0; 
  left:0; 
  z-index:-1;
}