*, *:before, *:after {
    -moz-box-sizing: border-box; -webkit-box-sizing: border-box; box-sizing: border-box;
}
button {
    position: fixed;
    padding: 10px;
    top: 5px;
    left: 5px;
    opacity: 0.8;
    display: none;
}
g > * {
    transition-property: stroke, stroke-width, transform, fill, font-size;
    transition-duration: .2s;
}
g.active > text {
    fill: blue;
    font-size: 100%;
}
g.active > polygon, g.active > ellipse, g.active > path {
    stroke: blue;
    stroke-width: 3px !important;
}
g.active.edge > polygon {
    fill: blue;
}
html, body { margin:10px; padding:0; }
svg {  height:100%; width:100%; }
svg.zoom {height: inherit; width: inherit;}