*{
 margin: 0px;
 padding: 0px;
 box-sizing: border-box;
}

body{
 background-color: #000;
 color: yellow;
}

main{
 height: 100vh;
 display: flex;
 flex-direction: column;
 justify-content: center;
 align-items: center;
 font-family: arial;
}