.listnode > circle {
    fill: #fff;
    stroke: #333;
    stroke-width: 1px;
}

.listnode > text {
    text-anchor: middle;
    alignment-baseline: middle;
}

.listnode-null > text {
    fill: red;
}

.instance-repr > .instance-body > rect {
    stroke: #333; 
    stroke-width: 1px;
}

.ll-instance > .instance-body > rect {
    fill: #f0fcff; 
}

.listnode-instance > .instance-body > rect {
    fill: #b0ffb0;
}