.history-timeline-wrap {
  position: relative;
  isolation: isolate;
}

.history-timeline {
  --track-gap: 88px;
  --track-scale: 1;
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
}

.history-path {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  overflow: visible;
  pointer-events: none;
  z-index: -1;
}

.history-path path {
  fill: none;
  stroke-width: 1;
  stroke-linecap: round;
  vector-effect: non-scaling-stroke;
}

.history-track {
  stroke: var(--accent-line);
  opacity: 0.6;
}

.history-progress {
  stroke: var(--accent);
  opacity: 0.72;
}

.history-head {
  fill: var(--accent);
  stroke: var(--bg);
  stroke-width: 1.5;
  opacity: 0;
}

.history-motion {
  opacity: 0;
  pointer-events: none;
}

.history-motion path {
  stroke: var(--accent);
  stroke-width: 0.9;
}

.history-drill-front {
  opacity: 0.68;
}

.history-drill-back {
  opacity: 0.26;
}

.history-ascent-wake {
  opacity: 0.4;
}

.history-motion .history-ascent-core {
  stroke-width: 1.5;
  opacity: 0.28;
}

.history-motion[data-direction="down"] .history-ascent,
.history-motion[data-direction="up"] .history-drill {
  display: none;
}

.history-step {
  --node-x: 4px;
  position: relative;
  width: calc(50% - var(--track-gap));
  min-height: 142px;
  padding-bottom: 30px;
  text-align: right;
}

.history-step + .history-step {
  margin-top: -22px;
}

/* The track drifts gently before opening into one broader final bend. */
.history-step:nth-child(2) {
  --node-x: 1px;
}

.history-step:nth-child(3) {
  --node-x: -7px;
}

.history-step:nth-child(4) {
  --node-x: -22px;
}

.history-step:nth-child(5) {
  --node-x: 32px;
}

.history-step:nth-child(odd) {
  margin-left: auto;
  text-align: left;
}

.history-node {
  position: absolute;
  top: 10px;
  left: calc(100% + var(--track-gap) + var(--node-x) * var(--track-scale));
  width: 5px;
  height: 5px;
  transform: translateX(-50%);
  border: 1px solid var(--accent-line);
  border-radius: 50%;
  background: var(--bg);
  transition:
    border-color 240ms ease,
    background-color 240ms ease;
}

.history-step.is-reached .history-node {
  background-color: var(--accent);
  border-color: var(--accent);
}

.history-step:nth-child(odd) .history-node {
  left: calc(-1 * var(--track-gap) + var(--node-x) * var(--track-scale));
}

.history-date {
  display: block;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
  transition: color 240ms ease;
}

.history-step.is-reached .history-date {
  color: var(--accent);
}

.history-step h3 {
  margin: 7px 0 10px;
  font-size: 23px;
}

.history-step p {
  color: var(--muted);
  font-size: 15px;
  line-height: 1.75;
}

.history-step:last-child {
  padding-bottom: 0;
  min-height: 0;
}

@media (max-width: 900px) {
  .history-timeline {
    --track-gap: 56px;
    --track-scale: 0.7;
  }
}

@media (max-width: 650px) {
  .history-step,
  .history-step:nth-child(odd),
  .history-step:nth-child(even) {
    --mobile-node-x: 0px;
    width: auto;
    min-height: 0;
    margin: 0 0 0 44px;
    padding-bottom: 34px;
    text-align: left;
  }

  .history-step:nth-child(2) {
    --mobile-node-x: 0px;
  }

  .history-step:nth-child(3) {
    --mobile-node-x: -2px;
  }

  .history-step:nth-child(4) {
    --mobile-node-x: -5px;
  }

  .history-step:nth-child(5) {
    --mobile-node-x: 7px;
  }

  .history-step:last-child {
    padding-bottom: 0;
  }

  .history-node,
  .history-step:nth-child(odd) .history-node {
    left: calc(-33px + var(--mobile-node-x));
  }

  .history-step h3 {
    font-size: 22px;
  }
}

@media print {
  .history-motion {
    display: none;
  }

  .history-step {
    break-inside: avoid;
  }
}

@media (prefers-reduced-motion: reduce) {
  .history-motion {
    display: none;
  }

  .history-node,
  .history-date {
    transition: none;
  }
}