* {
     box-sizing: border-box;
 }
 
 body {
     margin: 0;
     padding: 0;
 }
 
 h2 {
     color: blue;
     width: 100%;
     text-align: center;
     margin: 2em;
 }
 
 #container {
     width: 100vw;
     height: 100vh;
     border: thin solid black;
 }
 
 #line {
     height: 3em;
 }