style.css

body {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  margin: 0;
  background-color: #f6f6f6;
}
button{
  background-color: #6b6b6b;
  border: none;
  width: 100px;
  height: 50px;
  font-size: 20px;
  color: #fff;
  text-align: center;
  font-family: 'Franklin Gothic Medium', 'Arial Narrow', Arial, sans-serif;
  margin-bottom: 10px;
}
h1{
  font-family: 'Franklin Gothic Medium', 'Arial Narrow', Arial, sans-serif;
}
#header{
  position: relative;
  top: 0%;
  width: 100%;
  height: 10%;
  background-color: #6b6b6b;
  color: #fff;
  text-align: center;
  font-size: 70px;
  font-family: 'Franklin Gothic Medium', 'Arial Narrow', Arial, sans-serif;
  box-shadow: 0px 0px 3px #000;
}
#game{
  flex-direction: column;
  position: relative;
  margin-top: 10px;
  background-color: #cecece;
  color: #6b6b6b;
  text-align: center;
  font-size: 24px;
  font-family: 'Franklin Gothic Medium', 'Arial Narrow', Arial, sans-serif;
  box-shadow: 0px 0px 3px #000;
}