body {
  max-width: 46rem;
  margin: 4rem auto;
  padding: 0 1.25rem;
  color: #222;
  font-family: Georgia, "Times New Roman", serif;
  line-height: 1.6;
}

h1 {
  margin-bottom: 2rem;
}

h1.compact-heading {
  margin-bottom: 0.25rem;
}

ul {
  padding-left: 1.5rem;
}

a {
  color: #0645ad;
}

.breadcrumbs {
  margin-bottom: 2rem;
  color: #555;
  font-size: 0.9rem;
}

.site-footer {
  margin-top: 4rem;
  padding-top: 1rem;
  border-top: 1px solid #ccc;
  color: #555;
  font-size: 0.9rem;
}

.subtitle {
  margin-top: 0;
  color: #555;
}

.tooltip {
  position: relative;
  display: inline-block;
}

.tooltip-content {
  position: absolute;
  z-index: 10;
  top: calc(100% + 0.5rem);
  left: 0;
  display: none;
  width: min(38rem, calc(100vw - 3rem));
  max-height: min(70vh, 32rem);
  padding: 1rem;
  overflow-y: auto;
  border-radius: 0.3rem;
  background: #111;
  color: white;
  box-shadow: 0 0.4rem 1.25rem rgb(0 0 0 / 35%);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 1rem;
  line-height: 1.45;
}

.tooltip:hover .tooltip-content,
.tooltip:focus-within .tooltip-content {
  display: block;
}

.tooltip-content::before {
  position: absolute;
  bottom: 100%;
  left: 1rem;
  border: 0.45rem solid transparent;
  border-bottom-color: #111;
  content: "";
}

.tooltip-content strong {
  display: block;
  margin-bottom: 0.75rem;
  font-size: 1.05rem;
}

.tooltip-content p {
  margin: 0;
}

.tooltip-content p + p {
  margin-top: 0.75rem;
}

.tooltip-content ul {
  margin: 0.75rem 0 0;
  padding-left: 1.25rem;
}

.formula {
  white-space: nowrap;
  font-family: Georgia, "Times New Roman", serif;
  font-size: 1.15em;
}

.overline {
  text-decoration: overline;
}

dialog {
  width: min(90vw, 70rem);
  height: 90vh;
  padding: 0;
  border: 1px solid #777;
  border-radius: 0.25rem;
  box-shadow: 0 0.5rem 2rem rgb(0 0 0 / 35%);
}

dialog[open] {
  display: flex;
  flex-direction: column;
}

dialog::backdrop {
  background: rgb(0 0 0 / 65%);
}

.lightbox-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.5rem 0.75rem;
  background: #f3f3f3;
  border-bottom: 1px solid #bbb;
  font-family: Arial, Helvetica, sans-serif;
}

.lightbox-close {
  padding: 0.25rem 0.6rem;
  border: 1px solid #888;
  border-radius: 0.2rem;
  background: white;
  font: inherit;
  cursor: pointer;
}

.lightbox-frame {
  width: 100%;
  flex: 1;
  border: 0;
  background: white;
}