                             font-family: monospace;
                         }
                         */
+                        div.header { margin-bottom: 1rem; }
                         footer {
                             margin-top: 1rem;
                             border-top: .1rem solid #888;

        # progress takes two arguments: a float between 0 and 1 [%] and optionally a message
        {MARKERS}    = require('smc-util/sagews')
        @_html       = [] # list of elements
        cm           = @editor.codemirror
        progress     ?= _.noop


                        data_url = scene.static_image
                        out = "<div class='output sage3d'><img src='#{data_url}'></div>"
                else
                    # console.log 'msg.file', mark, mesg
                    if not @_output_ids[mark.id] # avoid duplicated outputs
                        @_output_ids[mark.id] = true
                        out = "<div class='output file'>#{mark.widgetNode.innerHTML}</div>"
        else if mesg.code?  # what's that actually?
            code = mesg.code.source
            out = "<pre><code>#{code}</code></pre>"
