style.css

/* style.css from git@github.com:rstudio/rmarkdown-cookbook.git*/

.infobox {
  padding: 1em 1em 1em 4em;
  margin-bottom: 10px;
  background: lightgray 5px center/3em no-repeat;
  border: 2px solid orange;
  border-radius: 10px;
}

.figure {
  text-align: center;
}
p.caption {
  color: #777;
  margin-top: 10px;
  text-align: left;
}
p code {
  white-space: inherit;
}
pre {
  word-break: normal;
  word-wrap: normal;
}
pre code {
  white-space: inherit;
}
.flushright {
  text-align: right;
}
pre.numberSource code > span > a:first-child::before {
  left: -0.3em;
}
.header-section-number {
  padding-right: .2em;
  font-weight: 500;
}
.level1 .header-section-number {
  display: inline-block;
  border-bottom: 3px solid;
}
.level1 h1 {
  border-bottom: 1px solid;
}
h1, h2, h3, h4, h5, h6 {
  font-weight: normal;
}
h1.title {
  font-weight: 700;
}
.book .book-body .page-wrapper .page-inner section.normal strong {
  font-weight: 600;
}
.book .book-body .page-wrapper .page-inner section.normal pre a {
  color: inherit;
}