h4 {
  font-size: 17px;
}
h5 {
  font-size: 16px;
}

#sidebar .sidebar-scrollbox {
font-size: 18px;
}
#sidebar .sidebar-scrollbox .chapter-item a {
  margin-bottom: 10px;
}
#sidebar .sidebar-scrollbox .chapter-item.affix a {
  margin-top: 20px;
  margin-bottom: 20px;
}
#sidebar .sidebar-scrollbox .chapter-item a strong {
  display: none;
  margin-bottom: 10px;
}

#sidebar .sidebar-scrollbox .part-title {
  margin-top: 20px;
  margin-bottom: 20px;
}

details {
  /* margin: 1rem auto; */
  /* width: 35em; */
  /* max-width: calc(100% - 2rem); */
  padding: 0 1rem;
  position: relative;
  border: 1px solid #ffffff;
  border-radius: 6px;
  background-color: #ffffff;
  color: #263238;
  transition: background-color 0.15s;
}
details > :last-child {
  margin-bottom: 1rem;
}
details::before {
  width: 100%;
  height: 100%;
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  border-radius: inherit;
  opacity: 0.15;
  box-shadow: 0 0.25em 0.5em #263238;
  pointer-events: none;
  transition: opacity 0.2s;
  z-index: -1;
}
details[open] {
  background-color: #FFF;
}
details[open]::before {
  opacity: 0.6;
}

summary.summary {
  padding: 1rem 2em 1rem 0;
  display: block;
  position: relative;
  font-size: 1.33em;
  font-weight: bold;
  cursor: pointer;
  background-color: #FFF;
  margin-inline: 0;
  padding-block: 40;
  padding-inline: 0;
}
summary.summary::before, summary.summary::after {
  width: 0.75em;
  height: 2px;
  position: absolute;
  top: 50%;
  right: 0;
  content: "";
  background-color: currentColor;
  text-align: right;
  transform: translateY(-50%);
  transition: transform 0.2s ease-in-out;
  inset-inline-start: 33.3em;
  mask-image: none;
  -webkit-mask-image: none;
}
summary.summary::after {
  transform: translateY(-50%) rotate(90deg);
}
[open] summary.summary::after {
  transform: translateY(-50%) rotate(180deg);
}
summary.summary::-webkit-details-marker {
  display: none;
}

code {
  padding: 0.2em;
  border-radius: 3px;
  background-color: #E0E0E0;
}
pre > code {
  display: block;
  padding: 1em;
  margin: 0;
}