body {
  width: 100%;
  text-align: center;
  margin: auto;
  padding-top: 1.5em;
  margin-bottom: 1em;
  font-family: serif;
}

h1.title {
  margin-top: 2.5em;
  font-size: 3em;
  color: green;
}

h2.title-date {
  margin-top: 3em;
}

img.left-arrow, img.contents {
  margin-right: 3em;
}

img.left-arrow, img.right-arrow {
  width: 40px;
}

img.contents {
  vertical-align: top;
  width: 35px;
}

img.grayscale {
  filter: grayscale(30%);
  opacity: 0.5;
}

img.diagram {
  margin-top: 2em;
  width: 100%;
  max-width: 800px;
}

div.highlighted-box {
  border: 1px solid green;
  max-width: 900px;
  width: calc(100% - 2em);
  margin: auto;
  margin-top: 2.5em;
  padding: 0.5em;
}

div.highlighted-box p {
  font-size: 1.2em;
}

span.small-reference {
  font-size: 0.8em;
}

p.slide-content {
  margin-top: 2em;
  font-size: 1.75em;
}

h3.slide-content-inline {
  display: inline;
  font-size: 1.2em;
}

h3.slide-content-inline::after {
  content: ":";
  margin-right: 0.5em;
}

p.slide-content-after-header {
  display: inline;
  font-size: 1.2em;
}

div.header-and-text-inline, p.slide-content-small {
  max-width: 900px;
  margin: auto;
  margin-top: 2.5em;
  padding-left: 1em;
  padding-right: 1em;
  text-align: left;
}

p.slide-content-small {
  font-size: 1.2em;
}

img.whole-page-vertical {
  max-height: 75vh;
  width: auto;
  padding-left: 1em;
  padding-right: 1em;
  margin-top: 2.5em;
  margin-bottom: 1em;
}

img.whole-page {
  max-width: 95%;
  padding-left: 1em;
  padding-right: 1em;
  margin-top: 2.5em;
}

a.whole-page-image {
  border: 0px;
}

span.highlighted-on {
  font-size: 1.5em;
  color: green;
}

span.highlighted-at-or-about {
  font-size: 1.5em;
  color: green;
  font-style: italic;
}

span.emphasis {
  font-weight: bold;
}

span.reference-title {
  font-style: italic;
}

div.quote {
  margin-top: 2.5em;
}

div.quote blockquote {
  display: inline-block;
  margin-left: 2px;
  padding-left: 0em;
  margin-right: 2px;
  font-size: 1.2em;
  margin-bottom: 5px;
  max-width: 55%;
}

img.left-quote {
  vertical-align: top;
}

img.right-quote {
  vertical-align: bottom;
}


h1.contents-title {
  margin: auto;
  padding-left: 2px;
  padding-right: 2px;
  margin-top: 1em;
  color: #228B22;
}

h2.contents-subtitle {
  margin: auto;
  padding-left: 2px;
  padding-right: 2px;
  margin-top: 1em;
  color: #228B22;
}

p.contents-instructions {
  max-width: 50%;
  margin: auto;
  padding-left: 2px;
  padding-right: 2px;
  margin-top: 2em;
}

div.contents {
  max-width: 800px;
  margin: auto;
}

ul.contents {
  list-style-type: none;
  padding-left: 0em;
  text-align: left;
  display: inline-block;
}

ul.contents li {
  margin-top: 1em;
}


h1.slide-content {
  font-size: 2.5em;
  max-width: 90%;
  margin: auto;
  margin-top: 1.5em;
}

h2.slide-content {
  max-width: 800px;
  margin: auto;
  margin-top: 1.25em;
  font-weight: lighter;
  font-size: 1.75em;
  padding-left: 1em;
  padding-right: 1em;
}

h3.slide-content {
  max-width: 50%;
  margin: auto;
  margin-top: 3em;
}

h4.slide-content {
  max-width: 50%;
  margin: auto;
  margin-top: 3em;
}

h1.thank-you {
  color: #702963;
}

span.quote-origins {
  font-size: 0.9em;
}

p.explanation {
  max-width: 50%;
  margin: auto;
  margin-top: 2em;
}

span.inline-example {
  margin-right: 3em;
}

span.strikethrough-1 {
  position: relative;
}

span.strikethrough-1:before, span.strikethrough-2:before {
  position: absolute;
  content: "";
  left: -5px;
  top: 50%;
  right: -5px;
  border-top: 1px solid;
  border-color: inherit;
  transform:rotate(-45deg);
}


a {
  color: #1F51FF;
  text-underline-offset: 0.1em;
}

a:hover {
  cursor: pointer;
}

div.menu a {
  border-bottom: none;
}

div.code {
  font-family: monospace;
  text-align: left;
}

div.poem {
  text-align: left;
}

@media screen and (max-width: 800px) {
  h1.slide-content, h2.slide-content, h3.slide-content, h4.slide-content,
  p.explanation, img.diagram, p.contents-instructions {
    max-width: 100%;
    padding-left: 2px;
    padding-right: 2px;
  }

  blockquote {
    max-width: 100%
  }

  h1.contents-title {
    margin-top: 0em;
  }
}