.square, .circle {
    width: 100px;
    height: 100px;
}
.circle {
    border-radius: 50%;
}
#blockGreen {
    background-color: rgb(104, 238, 104);
}
#blockYellow {
    background-color: rgb(250, 250, 85);
}
  #container {
    background-color:aquamarine; margin:0
  }