body {
  font-family: sans-serif;
  line-height: 2em;

  margin-left: 30%;
  margin-right: 10%;
  margin-bottom: 5em;
}

/* headings */
  th, h1, h2, h3, h4, h5, h6, .title {
    font-family: serif;
  }

  h1, h2, h3, h4, h5, h6 {
    margin-top: 5em;
    padding: 0.5em;
  }

  h1, h2, h3 {
    text-align: center;
  }

  h1 {
    padding: 1em;
    background-color: mistyrose;
  }

  h2 {
    background-color: bisque;
  }

  h3 {
    background-color: oldlace;
  }

/* table of contents */

  #navigation {
    position: fixed;
    left: 0px;
    top: 0px;
    bottom: 0px;

    width: 20%;
    padding: 1em;
    overflow: auto;

    background-color: white;
  }

  #navigation li {
    margin-left: -1em;
  }

  #navigation h1 {
    padding: 0.5em;
    margin-top: 0px;
  }

/* admonitions */
  .admonition {
    border: thin solid steelblue;
    background-color: aliceblue;
    padding: 1em;
  }

  .admonition img {
    margin-right: 2em;
  }

/* source code */
  tt {
    font-weight: bold;
    background-color: lemonchiffon;
  }

  pre, blockquote .code {
    padding: 1em;
    line-height: normal;
    overflow: auto;
    display: block;
  }

  pre {
    border: thin solid darkgray;
    background-color: whitesmoke;
  }

  .code {
    border: thin solid darkkhaki;
    background-color: ivory;
  }


/* tables */
  th, td {
    padding: 1em;
    border: thin solid silver;
  }

  th {
    background-color: whitesmoke;
  }

/* formal blocks; see http://www.sagehill.net/docbookxsl/FormalTitles.html */
  .formal {
    margin: 1em;
  }

  .title {
    display: block;
    font-size: large;
  }

  .formal .title {
    text-align: center
  }

  /* center-align any tables and images */
    .formal table, .formal img, #navigation img {
      margin-left: auto;
      margin-right: auto;
    }

    .formal img, #navigation img {
      display: block;
    }

/* misc. */
  .cover-page {
    text-align: center;
  }

  a img {
    border: none;
  }


  /* extra spacing before big block elements */

  .admonition, .figure {
    margin-top: 3em;
  }