body{
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    box-sizing: border-box;
    padding: 0px;
    margin: 0px;
}
.container {
    display: flex;
    flex-wrap: wrap;
    width: 860px;
    height: 860px;
    border: 2px solid #333;
    background-color: white;
  }
  
  .square {
    box-sizing: border-box;
    border: 1px solid black;
    flex: 1 0 auto;
  }

.btns {
    margin: 10px;
    padding: 10px;
    font-size: 16px;
    cursor: pointer;
}
button{
  width: 150px;
  height: 90px;
  background-color: blueviolet;
  border-radius: 10px;
  font-size: large;
  color: aliceblue;
  font-weight: 900;
  padding: 10px;
  font-family: 'Courier New', Courier, monospace;
}