* {box-sizing:border-box}
* {font-family: 'Courier New', Courier, monospace;}
* body{
  background-color: #ffff80;
}
.container {
    width: 90%;
    margin: 0 auto;
    display: flex;
    justify-content: space-around;
    align-items: center;
    flex-wrap: wrap;
}
.box {
    background-color: #3498db;
    color: #fff;
    padding: 20px;
    margin: 10px;
    border-radius: 5px;
    flex: 1 0 200px;
}
h1,h2,h3,h4,h5,h6{
    text-align: center;
}