svg * { transform-box: fill-box; transform-origin: 50% 50%; }

svg .city {
    transition: transform 200ms ease-in-out;
}

svg .city {
    fill: #fff;
    z-index: 2;
    stroke: #111;
    stroke-width: 3;
    cursor: pointer;

    transform: scale(1);
    transform-origin: 50% 50%;
}

svg .city:hover { transform: scale(1.1); }
svg .city.dragging { cursor: grabbing; transform: scale(1.2); }

svg .road {
    stroke: #ccc;
    stroke-width: 2;
    z-index: 1;
    stroke-linecap: round;
}