body {
    font-family: "Courier New", Courier, monospace;
    font-size: .85em;
}

header {
    text-align: center;
}

h2 {
    text-align: center;
    font-size: 1.2em;
    border-top: 2px dashed yellow;
    border-bottom: 2px dashed yellow;
}

input[type=text] {
    width: 40px;
    height: 40px;
    margin-left: 20px;
    background-color: #DADADA;
    font-size: 1.2em;
}

input[type=submit] {
    width: 200px;
    font-size: 2em;
}

#calculator {
    border: 1px solid #dadada;
    border-radius: 4px;
    padding: 4px;
}

.input-area {
    background-color: #42FF8C;
    padding: 8px;
    margin: 8px;
    text-align: center;
    border-radius: 8px;
}

.operator-choices {
    text-align: left;
}

.output-area {
    background-color: #333333;
    color: #FFFFFF;
    padding: 8px;
    margin: 8px;
    font-size: 1.5em;
}