:root {
  color-scheme: light dark;
}

html {
  /* scroll-behavior: smooth; */
  scroll-behavior: instant;
}

body {
  margin: 0;
  padding: 0;
  background: #fff;
  color: #1a1a1a;
  font-family: Georgia, 'Times New Roman', serif;
  line-height: 1.6;
}

.doc {
  max-width: 42em;
  margin: 0 auto;
  padding: 2.5rem 1.25rem 5rem;
}

.centreHeading {
  text-align: center;
}

.pdf-image {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 0 0 2rem;
}

.centreImage {
  display: block;
  margin: auto;
}

.download {
  font-family: -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  font-size: 0.9rem;
  margin-bottom: 2.5rem;
  position: sticky;
  top: 1rem;
  right: 1rem;
}

.download a {
  display: inline-block;
  padding: 0.5rem 1rem;
  border: 1px solid #ccc;
  border-radius: 6px;
  font-weight: bold;
  text-decoration: none;
  color: white;
  background: orangered;
}

.download a:hover {
  background: darkred;
}

#topBtn {
  position: sticky;
  bottom: 192px;
  /* ~2 inches from viewport bottom, while stuck */
  float: right;
  /* or margin-left: auto if article uses flex/grid */
  right: 5rem;
  cursor: pointer;
  border-radius: 50%;
  -webkit-transition: opacity 0.5s ease-in-out;
  transition: opacity 0.5s ease-in-out;
  /* height: 40px;
  width: 40px; */
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  -ms-border-radius: 50%;
  -o-border-radius: 50%;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.25s ease, visibility 0.25s;
}

#topBtn.show {
  opacity: 0.4;
  visibility: visible;
}

#topBtn.show {
  opacity: 0.6;
  visibility: visible;
  transform: translateY(0);
}

#topBtn:hover {
  background: #555;
}

article h1,
article h2,
article h3 {
  font-family: -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.25;
  color: #111;
}

article h1 {
  font-size: 1.9rem;
  margin: 0 0 1.5rem;
  text-align: center;
}

article h2 {
  font-size: 1.35rem;
  margin: 2.5rem 0 0.9rem;
}

article h3 {
  font-size: 1.1rem;
  margin: 2rem 0 0.75rem;
}

article p {
  font-size: 1.4rem;
  margin: 0 0 1.1rem;
}

article sup {
  font-size: 0.7em;
  line-height: 0;
  vertical-align: super;
}

.centre {
  text-align: center;
}

.quote {
  font-style: italic;
  margin: 0 2rem 1.1rem;
}

#notes {
  margin-top: 3rem;
  font-family: -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
  font-size: 1.2rem;
  color: #444;
}

#notes hr {
  border: none;
  border-top: 1px solid #ddd;
  margin: 0 0 1.5rem;
}

#notes h2 {
  font-size: 1.2rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin: 0 0 1rem;
  color: #111;
}

#notes ol {
  padding-left: calc(1cm + 1.4rem);
  margin: 0;
}

#notes li {
  margin-bottom: 0.6rem;
  line-height: 1.5;
}

@media (prefers-color-scheme: dark) {
  body {
    background: #14161a;
    color: #e6e6e6;
  }

  article h1,
  article h2,
  article h3 {
    color: #f2f2f2;
  }

  .download a {
    border-color: #444;
    color: #e6e6e6;
  }

  .download a:hover {
    background: #1f2227;
  }

  #notes {
    color: #aaa;
  }

  #notes hr {
    border-top-color: #333;
  }

  #notes h2 {
    color: #888;
  }
}

#notes {
  font-family: Arial, sans-serif;
  margin-inline: auto;
  max-width: 60ch;
}