body {
  background-color: #10bfeb;

}

.container {
    display: flex;
    flex-wrap: wrap;
  text-align:center;
  width:100%;
  }
  
#child {
    flex: 1 1 900px; 
    border: 0px solid white;

    font-size: 2rem;
    text-align: center;
  }