<vbox flex="1">
    <style>
        @container {
            overflow: hidden;
            flex-basis: 1em;
        }
        pre {
            background: #333;
            color: #EEE;
            padding: 1em;
            overflow-y: auto;
            & * + div.Important {
                margin-top: 0.5em;
            }
            & div.Important {
                font-weight: bold;
                color: lighten(@primary_color, 20%);
            }
        }
    </style>
    <vbox flex="1" anon-id="container">
        <pre flex="1" anon-id="output"></pre>
    </vbox>
</vbox>
