style.css

:root {
  --theme-color: rgb(43, 55, 140);
  --theme-color-light: rgba(43, 55, 140, 0.05);
  --theme-color-medium: rgba(43, 55, 140, 0.1);
  --dark-color: rgba(0,0,0,0.8);
  --dark-focused: cornflowerblue;
}
body {
  font-family: "Helvetica Neue", helvetica, arial, "sans serif";
}
.sidebar {
  background: var(--dark-color);
  color: white;
}
.sidebar ul li a {
  color: white;
}
.sidebar ul li.active>a {
  color: var(--dark-focused); 
  border-right: 5px solid;
}
.markdown-section {
  max-width: 1000px;
  margin: 20px;
}
.markdown-section pre code {
  background: none;
  color: white;
}
.markdown-section pre {
  padding: 20px;
  background: rgba(0,0,0,0.8);
  color: white;
}
.markdown-section code, .markdown-section pre {
  font-size: 12px;
  line-height: 16px;
}
.markdown-section h1 {
  font-size: 60px;
  letter-spacing: -4px;
}
.anchor span {
  color: var(--dark-color);
}
.markdown-section ol, .markdown-section p, .markdown-section ul {
  line-height: 1.4rem;
}
.videoWrapper {
  position: relative;
  padding-bottom: 56.25%; /* 16:9 */
  height: 0;
  margin-top: 10px;
}
.videoWrapper iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}