body {
    user-select: none;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
      "Helvetica Neue", Arial, sans-serif;
    color: rgb(54, 54, 54);
    margin-left: auto;
    margin-right: auto;
    max-width: 1200px;
    padding: 0px;
    border: 0px;
}

h1 {
  color: rgb(54, 54, 54);
  font-size: 4em;
  font-weight: 500;
}

h2 {
  color: rgb(54, 54, 54);
  font-weight: 400;
  font-size: 2em;
}

p {
  color: rgb(54, 54, 54);
  font-size: 1.3em;
  font-weight: 300;
  line-height: 1.45;
}

.column {
  margin-left: auto;
  margin-right: auto;
  margin-top: 10vh;
  max-width: 60vw;
}

.title_div {
  max-width: 90%;
}

.title {
  font-weight: 400;
  text-align: center;
}

.subtitle {
  text-align: center;
  margin-top: 8vh;
}

.intro {
  margin-bottom: 7vh;
}

.text {
  text-align: justify;
}

.book {
  margin-top: 6vh;
}

.book-title {
  text-align: center;
  margin-bottom: 1vh;
}

.book-description {
  text-align: justify;
}

.book-tags {
  text-align: right;
}

.book-tags p {
  font-size: 1.05em;
}

.button {
  position: fixed;
  left: 5vw;
  right: auto;
  bottom: 8vh;
  top: auto;
}

.rubutton {
  position: fixed;
  left: 5vw;
  right: auto;
  bottom: 3vh;
  top: auto;
}

.back {
  height: min-content;
  width: 90px;
  text-align: center;
  display: block;
  text-decoration: none;
  font-size: 1.1em;
  border: rgb(54, 54, 54) 1px solid;
  color: rgb(54, 54, 54);
  padding: 3px;
  padding-left: 5px;
  padding-right: auto;
  margin-right: auto;
  margin-top: 20px;
  border-radius: 0px;
  transition: border-radius 0.5s;
}

.back:hover {
  top: 5px;
  transition: 0.5s;
  color: #0000007a;
  border: #0000007a 1px solid;
  border-radius: 10px;
}

.book-list {
  color: rgb(54, 54, 54);
  font-size: 1.3em;
  font-weight: 300;
  line-height: 1.45;
  padding-left: 1.3em;
}

.book-list li {
  margin-bottom: 0.15em;
}

@media screen and (max-width: 900px) {
  body {
    width: 90vw;
    margin-left: 6vw;
    margin-right: 6vw;
  }

  .button {
    display: none;
  }

  .rubutton {
    display: none;
  }
}

@media (max-width: 768px) {
  .column {
    margin-top: 5vh;
    max-width: 90vw;
  }

  h1 {
    font-size: 3em;
  }

  h2 {
    font-size: 1.5em;
  }

  p {
    font-size: 1em;
  }

  .book-tags p {
    font-size: 0.95em;
  }

  .book-list {
    font-size: 1em;
  }
}