style.css

@import url('https://fonts.googleapis.com/css2?family=Open+Sans:ital,wght@0,300..800;1,300..800&display=swap');
html {
  font-family: "Open Sans", sans-serif;
  font-optical-sizing: auto;
  font-weight: normal;
  font-style: normal;
  font-variation-settings: "wdth" 100;
}
.container {
  max-width: 80rem;
  margin-inline: auto;
  padding: 10px;
  background: lightgray;
}
body {
  background-color: grey;
}
#timeline-chart {
  background-color: paleturquoise;
}
#examples {
  background-color: antiquewhite;
}

.controls {
  display: flex;
  flex-wrap: wrap;
  margin-block-end: 10px;
  row-gap: 0.3rem;
  column-gap: 1rem;
}
.controls .markers {
  color: white;
  background-color: #00f;
  display: flex;
  column-gap: 0.3rem;
  align-items: center;
}
.controls .colour-coding {
  background-color: #0f0;
}
.controls .buttons {
  flex-grow: 1;
  background-color: #f00;
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 0.5rem;
}
.controls button {
  display: flex;
  flex-direction: row;
  flex-wrap: nowrap;
  align-items: center;
  gap: 0.3em;
  color: white;
  font: inherit;
  background: inherit;
  border: 1px solid white;
  border-radius: 2em;
  padding-inline: 1em;
  /* padding-block: 0.2em; */
}
.controls select {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
}
.controls button:hover {
  color: #f00;
  background: white;
}
.controls button svg {
  height: 1em;
  aspect-ratio: 1/1;
}


input[type="checkbox"] {
  appearance: none;
  background-color: inherit;
  font: inherit;
  color: currentColor;
  width: 1.15em;
  height: 1.15em;
  border: 0.15em solid currentColor;
  border-radius: 0.15em;
  display: grid;
  place-content: center;
}
input[type="checkbox"]::before {
  content: "";
  width: 0.65em;
  height: 0.65em;
  transform: scale(0);
  transition: 120ms transform ease-in-out;
  box-shadow: inset 1em 1em var(--form-control-color, white);
}
input[type="checkbox"]:checked::before {
  transform: scale(1);
}