h1 {color:white; font-size: 72px;}
h2 {color:darkcyan; font-size: 42px;}

body {
    background-color: black;
     background-image: url("bg.jpg");
      background-repeat: no-repeat;
      background-attachment: fixed;
    background-size: 100% auto;
    text-align: center; 
    color:yellow;
    font-family: Arial, Helvetica, sans-serif;
}

.flex-container {
  display: flex;
 justify-content: center;

}

.flex-container > div {
  background-color: black;
  margin: 10px;
  padding: 20px;
}