.section-marker {
  --sm-color: 242, 239, 232;
  position: fixed;
  top: 0;
  bottom: 0;
  left: clamp(18px, 2vw, 30px);
  z-index: 15;
  width: 80px;
  color: rgb(var(--sm-color));
  font-family: "Intro Rust", sans-serif;
  pointer-events: none;
  opacity: 0;
  transition: opacity 600ms ease, color 400ms ease;
}

.section-marker[data-tone="light"] {
  --sm-color: 57, 56, 51;
}

.section-marker.is-ready {
  opacity: 1;
}

.section-marker.is-ready.is-hidden {
  opacity: 0;
}

.section-marker-tick {
  position: absolute;
  left: 0;
  width: 36px;
  height: 1px;
  margin-top: -0.5px;
  background: rgb(var(--sm-color));
  transform-origin: left center;
  will-change: transform, opacity;
}

.section-marker-number {
  position: absolute;
  left: 44px;
  font-size: 0.72rem;
  line-height: 1;
  letter-spacing: 0.14em;
  font-variant-numeric: tabular-nums;
  opacity: 0;
  translate: -6px 0;
  transform: translateY(-50%);
  will-change: opacity, translate;
}

/* Pas de repère sur mobile ni sur petits écrans : il empiéterait sur le contenu. */
@media (max-width: 1100px) {
  .section-marker {
    display: none;
  }
}