.site-header {
  border-top: 3em solid #E06610;
  border-bottom: 3em solid #E06610;
  padding: 3em 0;
  text-align: center;
}

.site-header img {
  max-width: 50%;
  width: 250px;
  margin: 2em auto;
  display: block;
}

.site-header h1 {
  text-align: center;
  font-size: 3em;
}

.site-header h2 {
  font-size: 1.5em;
}

.site-header .gumroad-button {
  margin-top: 2em;
}

.gumroad-button {
  margin-bottom: 1em;
}

.chapters p {
  line-height: 1.6;
  color: #666;
  font-size: 0.9rem;
}

.container {
  max-width: 960px;
}

.about-book {
  margin-bottom: 1.5rem;
}

p.free-updates {
  font-size: 1.2rem;
  font-weight: bold;
  margin-bottom: 0.5em;
}

hr {
  margin-top: 1rem;
  margin-bottom: 1rem;
  width: 50%;
}

.testimonials .row {
  justify-content: center;
}

.testimonial {
  text-align: center;
  min-width: 260px;
  margin-bottom: 1.5rem;
}

.testimonial img {
  width: 80px;
  height: 80px;
  border-radius: 40px;
  border: 3px solid #666;
}

.testimonial a:hover {
  text-decoration: none;
}

.testimonial .h4 a {
  color: #333;
  font-size: 1.6rem;
}

.testimonial p a {
  color: #666;
}

.chapters h4 {
  margin: 1em 0 0.6em 0;
}

.promo, .promo-poster {
  width: 420px;
  max-width: 100%;
  text-align: center;
}

.promo p {
  padding: 1em 0;
}

.promo .btn-primary {
  background-color: #5600D8 !important;
  border: none;
  width: 100%;
}

@media (max-width: 1000px) {
  .chapters, .testimonials {
    width: 75%;
    margin: 0 auto;
  }

  .site-header img {
    margin: 1.5em auto;
  }
}

@media (max-width: 650px) {
  .chapters, .testimonials {
    width: 90%;
  }

  .site-header {
    padding: 2em;
  }
}