.header {
   
   	font-family:'Barlow GX';
	src: url('https://s3-us-west-2.amazonaws.com/s.cdpn.io/209981/BarlowGX.ttf') format('woff-variations');
  
    height:75px; 
    width: 350px; 
    background-color:whitesmoke; 
   color: darkslategray;
    float: center; 
    padding:10px; 
    margin:20px;
    text-align:centre; 
    font-size:24px;
  }

  .app {
    height:750px;
    width: 350px; 
    background-color:whitesmoke;
    color: darkslategray;
    float: center; 
    padding:10px; 
    margin:20px;
    font-size:18px;
    font-style:bold;
  }

  input[type="button"] {
   background-color: pink;
  }