index.css

body {
    font-family:'Lucida Sans Unicode', 'Lucida Grande', Arial, sans-serif;
    background-image: url("https://cdn.pixabay.com/photo/2020/04/07/07/39/blackjack-5012424_1280.jpg");
    background-size: cover;
    background-repeat: no-repeat;
    background-position: center;
    height: 100vh;
    font-weight: bold;
    color: white;
    text-align: center;
    margin: 0;
}

#container {
     background-color: rgba(108, 106, 98, 0.4);
     width: 250px;
     padding: 10px;
     padding-bottom:20px;
     margin: 20vh auto;
     border: solid black 4px;
}

h1 {
    color: goldenrod;
}

#message-el {
    font-style: italic;
}

button {
    color: #016f32;
    width: 150px;
    background: goldenrod;
    padding-top: 5px;
    padding-bottom: 5px;
    font-weight: bold;
    border: none;
    border-radius: 2px;
    margin-bottom: 2px;
    margin-top: 2px;
}