* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}
/* html {
  scroll-behavior: smooth;
} */

#back-to-top-btn {
  display: none;
  position: fixed;
  bottom: 20px;
  right: 20px;
  font-size: 26px;
  width: 50px;
  height: 50px;
  background-color: #fff;
  color: #6CF54B;
  cursor: pointer;
  outline: none;
  border: 3px solid #6CF54B;
  border-radius: 50%;
  transition-duration: 0.2s;
  transition-timing-function: ease-in-out;
  transition-property: background-color, color;
}
#back-to-top-btn:hover, #back-to-top-btn:focus {
  background-color: #6CF54B;
  color: #fff;  
}

@media(max-width: 992px) {
  .container { padding: 20px 100px; }
  #back-to-top-btn { font-size: 22px; width: 40px; height: 40px; bottom: 15px; right: 15px; }
}
@media(max-width:768px) {
  body { font-size: 16px; }
  .container { padding: 10px 50px; }
  h1 { font-size: 26px; }
  h2 { font-size: 22px; }
  hr { margin: 30px 0; }
  #back-to-top-btn { font-size: 18px; width: 32px; height: 32px; bottom: 6px; right: 6px; }
}

/* Animations */
.btnEntrance {
  animation-duration: 0.5s;
  animation-fill-mode: both;
  animation-name: btnEntrance;
}
/* zoomIn */
/* @keyframes btnEntrance { 
  from {
    opacity: 0;
    transform: scale3d(0.3, 0.3, 0.3);
  }
  to {
    opacity: 1;
  }    
} */

/* fadeInUp */
@keyframes btnEntrance {
  from {
    opacity: 0;
    transform: translate3d(0, 100%, 0);
  }
  to {
    opacity: 1;
    transform: translate3d(0, 0, 0);
  }
}

.btnExit {
  animation-duration: 0.25s;
  animation-fill-mode: both;  
  animation-name: btnExit;
}
/* zoomOut */
/* @keyframes btnExit {
  from {
    opacity: 1;
  }
  to {
    opacity: 0;
    transform: scale3d(0.3, 0.3, 0.3);
  }
} */

/* fadeOutDown */
@keyframes btnExit {
  from {
    opacity: 1;
  }
  to {
    opacity: 0;
    transform: translate3d(0, 100%, 0);
  }
}