body {
    background-color: #f4f4f4;
    color: #555;
    max-width: 800px;
    padding: 20px;
    font-size: 16px;
    font-weight: 200;
    margin: 0 auto;
    font-family: Helvetica Neue,arial,verdana;
}

h1 {
    font-size: 1.8em;
    line-height: 2em;
}

h2 {
    font-size: 1.5em;
    line-height: 1.7em;
}

h3 {
    font-size: 1.2em;
    line-height: 1.3em;
}

div.item-wrapper div.playground-container > div {
    width: 45%;
    height: auto;
    display: inline-block;
    margin-left: 3%;
}

div.item-wrapper div.playground-container > div textarea {
    width: 100%;
    height: 200px;
}

div.item-wrapper div.playground-container > div pre {
    width: 100%;
    height: 200px;
}

@media all and (max-width: 600px) {
    div.item-wrapper div.playground-container > div {
        width: 90%;
        display:block;
        margin: 0 auto;
    }
}