html {
  min-height: 100%;
  font-size: 100%;
  background: #162A67 url('../i/bg.jpg') no-repeat center top scroll;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}

body {
  margin: 0;
  line-height: 1.5;
  color: #fff;
  font-size: 15px;
  font-family: 'Noto Serif', serif;
}

p {
  margin: 0 0 1em;
  padding: 0;
}

.home-page {
  padding: 20px;
  box-sizing: border-box;
}

.about-page {
  padding: 40px 20px;
}

.book-desc {
  text-align: center;
}

.book-desc-title {
  text-transform: uppercase;
  margin: 10px 0;
  font-size: 8vw;
}

.book-desc-author,
.book-desc-subtitle {
  text-transform: uppercase;
  margin-bottom: 30px;
  font-size: 4.6vw;
}

.book-desc-text {
  margin-bottom: 65px;
  padding: 0 10px;
}

.link-primary {
  color: #fff;
}

.link-primary:hover {
  color: #c9d8f9;
}

.book-buttons .link-btn {
  vertical-align: top;
}

.link-btn {
  position: relative;
  display: inline-block;
  width: 70%;
  margin: 0 0 12px 0;
  padding: 15px 30px 14px;
  border: 2px solid #fff;
  border-radius: 50px;
  text-decoration: none;
  text-transform: uppercase;
  color: #fff;
  background-color: transparent;
  font-size: 15px;
  font-family: 'Noto Serif', serif;
  cursor: pointer;
  box-sizing: border-box;
}

.link-btn:hover {
  background-color: #fff;
  color: #1B266A;
}

.link-btn-alt-1 {
  padding-top: 10px;
  padding-bottom: 20px;
}

.link-btn-hint {
  position: absolute;
  right: 18px;
  font-size: 16px;
  opacity: 0.3;
}

.link-btn-intro {
  position: absolute;
  font-size: 9px;
  opacity: 0.5;
  bottom: 10px;
  left: 50%;
  margin-left: -28px;
  white-space: nowrap;
  text-transform: lowercase;
}

/* Helpers */

.important {
  margin-bottom: 2em;
}

.text-center {
  text-align: center;
}

/* Popup */

.popup-overlay {
  position: fixed;
  width: 100%;
  height: 100%;
  display: none;
  justify-content: center;
  align-items: center;
  top: 0;
  left: 0;
  z-index: 20;
  background-color: #1c2866;
  -webkit-transition: all 0.3s;
  -moz-transition: all 0.3s;
  -ms-transition: all 0.3s;
  transition: all 0.3s;
}

.popup-overlay-visible {
  display: flex;
}

.popup {
  position: relative;
  width: 90%;
  margin: 0 auto;
  padding: 40px;
  background-color: #2f3e8e;
  border-radius: 20px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
  box-sizing: border-box;
  /*position: fixed;*/
  /*max-width: 300px;*/
}

.popup-header {
  font-size: 18px;
  font-weight: bold;
  margin-bottom: 14px;
  text-transform: uppercase;
}

.popup-control-close {
  position: absolute;
  width: 60px;
  bottom: -75px;
  left: 50%;
  margin-left: -30px;
  font-size: 42px;
  text-align: center;
  cursor: pointer;
}

.popup .link-btn {
  text-align: center;
  width: 95%;
}

@media (min-width: 768px) {
  html {
    background-attachment: fixed;
  }

  .book-desc-author {
    margin-bottom: 30px;
    font-size: 22px;
  }

  .book-desc-title {
    font-size: 4vw;
  }

  .book-desc-subtitle {
    font-size: 1.8vw;
  }

  .link-btn {
    width: auto;
    margin: 0 12px 12px 0;
    padding-left: 40px;
    padding-right: 40px;
  }

  .popup {
    width: 40%;
  }
}

@media (min-width: 992px) {
  .home-page {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
  }

  .book-desc-title {
    font-size: 40px;
  }

  .book-desc-author {
    margin-bottom: 30px;
    font-size: 22px;
  }

  .book-desc-subtitle {
    margin-bottom: 45px;
    font-size: 18px;
  }

  .book-desc-text {
    padding: 0 28%;
    font-size: 18px;
  }
}