style.css

html {
    background-image: url("https://i.imgur.com/cSBRJkz.jpg");
}
.content-box {
    display: inline;
    background-color: rgba(198, 178, 169, 0.8);
    margin: 1em;
    flex: 1;
    padding: 1em;
    border-style: solid;
    border-width: 1px;
    border-color: black;

    }
body { 
    font-family: monospace;
    display: block;
    margin-left: auto;
    margin-right: auto;
    margin-top: 0 !important;
    margin-bottom: 0! important;
    max-width: 900px;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.2);
    padding-top: 1em;
    }
img {
    max-width: 100%;
}
#banner {
    display: block;
    background-color: white;
    font-color: blue;
    border-style: solid;
    border-width: 1px;
    border-color: black;
    margin-left: 1em;
    margin-right: 1em;
    text-align: center;
    background-color: rgba(147, 171, 191, 0.8);
}
#content-wrapper {
    display: flex;
}
#text-box {
}
#image-box {
    max-width: 30%;
}
#button-box {
    display: block;
    text-align: center;
    margin: auto;
}
button {
    display:block;
    margin: auto;
}