.nav.side {
  position: sticky;
  top: 90px;
}
h1, h2, article h3, article h4, article h5, article h6 {
  margin: auto;
  position: sticky;
  cursor: pointer;
  transition:
    height 0.5s ease,
    width 0.2s ease,
    font-size 0.2s ease,
    margin 0.3s ease,
    padding 0.1s ease,
    font-weight 0.8s ease,
    line-height 0.2s ease;
}

.is-sticky {
  width: 50%;
  padding: 0;
  margin: 0 auto;
  /* margin-left: 0%;
  margin-right: 0%; */
  z-index: 5;
  height: 40px;
  place-content: center;
  border-bottom: 1px solid var(--shade);
}
h2.is-sticky {
  font-size: 2em;
  font-weight: normal;
  width: max-content;
}
h3.is-sticky, h4.is-sticky {
  font-size: 1em;
  font-weight: normal;
}
h3.is-sticky {
  margin-right: 50% !important;
}
h4.is-sticky {
  margin-left: -50% !important;
  margin-left: 50% !important;
}
h3:has(~ h3.is-sticky),
h4:has(~ h4.is-sticky) {
  position: static;
}