#twitter-share-btn {
  width: 2.5rem;
  height: 2.5rem;
  font-size: 1.25rem;
  color: #56b8f5;
  background-color: #fff;
  cursor: pointer;
  border: 2px solid #56b8f5;
  border-radius: 50%;
  position: absolute;
  top: 0;
  left: 0;
  z-index: 10;
  display: none;
  transition: color 0.2s, background-color 0.2s ease-in-out;
}
#twitter-share-btn:hover {
  color: #fff;
  background-color: #56b8f5;
}
#twitter-share-btn i {
  pointer-events: none;
}
.btnEntrance {
  animation-duration: 0.2s;
  animation-fill-mode: both;
  animation-name: btnEntrance;
}
@keyframes btnEntrance {
  /* zoomIn */
  0% {
    opacity: 0;
    transform: scale3d(0.3, 0.3, 0.3);
  }
  100% {
    opacity: 1;
  }
}

@media (max-width: 992px) {
  .container {
    padding: 1.25rem 6rem;
  }
  h1 {
    font-size: 2.5rem;
  }
  h2 {
    font-size: 1.75rem;
  }
}
@media (max-width: 768px) {
  html {
    font-size: 12px;
  }
  .container {
    padding: 1rem 3rem;
  }
  h1 {
    font-size: 2rem;
  }
  h2 {
    font-size: 1.5rem;
  }
  hr {
    margin: 1.5rem 0;
  }
}