style.css

body {
    font-family: Helvetica, Arial, sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    color: #2c3e50;
    max-width: 75ch;
    margin: auto;
}

h1,
h2 {
    margin-top: 1.75em;
    line-height: 2em;
}

.sample-group h1,
h2 {
    border-top: 1px solid rgba(0, 0, 0, .2);
}

code {
    font-weight: bold;
    font-size: 120%;
    background: #f0f0f0;
}

button,
input,
select {
    padding: .5em .3em;
    margin: .5em 0 1em 0;
    border-radius: 0;
    font-family: inherit;
    font-size: inherit;
}

button {
    padding: .5em 1em;
}

button:hover {
    background: rgba(0, 0, 0, .2);
}

input[type=range] {
    padding: 0;
}

h1 button,
h2 button {
    padding: 0;
    width: 1.5em;
    height: 1.5em;
    border-radius: .3em;
    margin-right: .25em;
    margin-bottom: 0;
}

.error {
    color: darkred;
    font-weight: bold;
}

button.hide {
    display: none;
    margin-left: 5em;
}

label {
    display: flex;
    align-items: center;
    margin-left: 1em;
    gap: .5em;
    min-height: 1.75em;
}

/* crosswalk traffic light cycle parameters */
span.light {
    display: inline-block;
    width: 1em;
    height: 1em;
    border-radius: 50%;
    border: 4px solid rgba(0, 0, 0, .5);
    vertical-align: middle;
    margin-right: .1em;
}

span.light.red {
    background: red;
}

span.light.yellow {
    background: orange;
}

span.light.green {
    background: green;
}

/* animation */
div.ss-anim {
    position: relative;
    height: 300px;
}

div.ss-anim>div {
    position: absolute;
}

div.ss-anim .ss-queue {
    width: 1em;
    height: 1em;
    border-radius: 4px;
    transform: translate(-50%, -50%);
    background: orange;
    opacity: 0.03;
}

div.ss-anim .light {
    top: 5%;
    left: 50%;
    transform: translate(-50%, 0);
    background: rgba(0, 0, 0, 0.1);
    border: 2px solid rgba(0, 0, 0, .2);
    border-radius: 1em;
    padding: .1em;
}

div.ss-anim .light div {
    width: 1em;
    height: 1em;
    margin: .1em;
    border: 2px solid rgba(0, 0, 0, .5);
    border-radius: 1em;
    opacity: .2;
}

div.ss-anim .light .red {
    background: red;
}

div.ss-anim .light .yellow {
    background: yellow;
}

div.ss-anim .light .green {
    background: green;
}

div.ss-anim .street {
    width: 80%;
    height: 20%;
    top: 50%;
    left: 10%;
    background: rgba(0, 0, 0, 0.1);
    transform: perspective(400px) rotateX(30deg);
}

div.ss-anim .crosswalk {
    width: 10%;
    height: 20%;
    top: 50%;
    left: 45%;
    background-image: repeating-linear-gradient(45deg,
            black,
            black 10px,
            white 10px,
            white 20px);
    transform: perspective(400px) rotateX(30deg);
}

div.ss-anim .car-arr {
    top: 60%;
    left: 10%;
}

div.ss-anim .car-xing {
    top: 60%;
    left: 40%;
}

div.ss-anim .car-xed {
    top: 60%;
    left: 90%;
}

div.ss-anim .ped-arr {
    top: 85%;
    left: 10%;
}

div.ss-anim .ped-xing {
    top: 75%;
    left: 50%;
}

div.ss-anim .ped-xed {
    top: 45%;
    left: 50%;
}

div.ss-anim .ped-leave {
    top: 35%;
    left: 90%;
}

.ss-anim .ss-entity {
    position: absolute;
}

div.ss-anim .ss-entity.ped {
    opacity: 0.8;
}

div.ss-anim .time-now {
    top: 1em;
    right: 10%;
}

div.ss-anim .time-now span {
    font-weight: bold;
}

/* SVG animation*/
svg.ss-anim {
    width: 100%;
    height: 300px;
    /*overflow: visible;*/
}

svg.ss-anim g.light {
    fill: rgba(0, 0, 0, 0.1);
    stroke: rgba(0, 0, 0, 0.3);
    stroke-width: 2px;
}

svg.ss-anim g.light circle {
    opacity: 0.2;
}

svg.ss-anim g.light circle.red {
    fill: red;
}

svg.ss-anim g.light circle.yellow {
    fill: yellow;
}

svg.ss-anim g.light circle.green {
    fill: green;
}

svg.ss-anim .ss-queue {
    fill: orange;
    opacity: 0.3;
}

svg.ss-anim .street {
    fill: rgba(0, 0, 0, 0.1);
}

svg.ss-anim .crosswalk {
    fill: rgba(0, 0, 0, 0.3);
}

.ss-anim {
    width: 100%;
    height: 450px;
    border: 2px solid black;
    padding: 12px;
}

.ss-anim.asteroids {
    overflow: hidden;
    background: black;
    width: 80%;
    margin: auto auto;
}

table.params td,
table.params th {
    padding-left: 2em;
    font-size: 90%;
    text-align: right;
}

table.params .gpss {
    color: darkgreen;
}

table.params .ss {
    color: darkblue;
    display: inline-block;
    margin-bottom: 0.5em;
}

.sample-group .body {
    margin-left: 1em;
}

/* style the steering animation elements */
svg.ss-anim.steering {
    display: block;
    max-height: 60vh;
    margin: 1em auto;
    border: 4px solid lightgrey;
    border-radius: 0.5em;
    overflow: hidden;
}