.site-container{
  display: flex; 
  justify-content: center;
} 
.container-grid {
  padding: 0; 
  margin: 0;
  list-style: none;
  display: -webkit-box;
  display: flex;
  -webkit-flex-flow: row wrap; 
  justify-content: space-around;
} 
.container-item {
  width: 300px;
  height: 600px;
  margin-top: 10px;
  color: white;
  font-weight: bold;
  text-align: center;
}