* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
.intro {
  position: relative;
  margin: 2em;
  padding: 0.2em 0.6em;
  cursor: pointer;
  color: #fff;
  font-size: 2em;
  max-width: 26em; font-weight: 600;

}
.CrossFade4 .intro,
.CrossFade3 .intro,
.CrossFade2 .intro {
  position: relative;
  margin: 2em;
  padding: 0.2em 0.6em;
  cursor: pointer;
  color: #fff;
  font-size: 2em;
  max-width: 26em; font-weight: 600;

}

.intro h1 {
  margin-bottom: 0.5em; 
  font-weight: 800;
text-shadow: 1px 2px 4px rgba(0, 0, 0, 0.6);
  }

.intro button{float:right;}


#CrossFade {
  background: #fff;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-align: end;
      -ms-flex-align: end;
          align-items: flex-end;
  height: 100vh;
  overflow: hidden;
  position: relative;
}

.CrossFade2 {
 background: url(../assets/img/header-bg2.jpg) no-repeat;
 background-position: center 25%; 
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-align: end;
      -ms-flex-align: end;
          align-items: flex-end;
  height: 80vh;
  overflow: hidden;
  position: relative;
}


.CrossFade3 {
 background: url(../assets/img/bg1.jpg) no-repeat;
 background-position: center 25%; 
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-align: end;
      -ms-flex-align: end;
          align-items: flex-end;
  height: 80vh;
  overflow: hidden;
  position: relative;
}

.CrossFade4 {
 background: url(../assets/img/header-bg3.jpg) no-repeat;
 background-position: center 25%; 
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-align: end;
      -ms-flex-align: end;
          align-items: flex-end;
  height: 80vh;
  overflow: hidden;
  position: relative;
}

@media (max-width: 768px) {
   
#CrossFade {
  height: 70vh;
 }

  .intro {
    position: relative;
    margin: 1em!important;
    padding: 0.1em 0.1em;  
    
   }
   
   .intro h1 {
     font-size: 2rem;
  font-weight: 400;
  }

button {
      font-weight: 400;
      font-size: 1.4rem;
  }

}

#CrossFade img,
.CrossFade img{
  position: absolute;
  min-width: 100%;
  min-height: 100%;
  height: auto; 
  background: #000;
  -webkit-backface-visibility: hidden;
          backface-visibility: hidden;
  opacity: 0;
  -webkit-transform: scale(1.4) rotate(12deg);
          transform: scale(1.4) rotate(12deg);
  -webkit-animation: CrossFade 24s infinite;
          animation: CrossFade 24s infinite;
}
#CrossFade img:nth-child(3) {
  -webkit-animation-delay: 6s;
          animation-delay: 6s;
}
#CrossFade img:nth-child(2) {
  -webkit-animation-delay: 12s;
          animation-delay: 12s;
}
#CrossFade img:nth-child(1) {
  -webkit-animation-delay: 18s;
          animation-delay: 18s;
}
/* 

$duration = 12
$slides = 4
$step = $duration/$slides
setDelayRevers($duration, $slides)
  
  for index in (2..$slides)
    &:nth-child({index -1}) 
      animation-delay ($step*index)s

#CrossFade
  height 100vh
  overflow hidden
  position relative
  
  display flex
  img
    align-self center
    position absolute
    
    min-width 100%
    min-height 100%
    height auto
    
    backface-visibility hidden
    opacity 0
  
    transform scale(1.4) rotate(12deg)
    animation CrossFade ($duration)s infinite 
    setDelayRevers($duration, $slides)   
@keyframes CrossFade
  25%
    opacity 1
    transform scale(1) rotate(0)
  40%
    opacity 0
    
*/
@-webkit-keyframes CrossFade {
  25% {
    opacity: 1;
    -webkit-transform: scale(1) rotate(0);
            transform: scale(1) rotate(0);
  }
  40% {
    opacity: 0;
  }
}
@keyframes CrossFade {
  25% {
    opacity: 1;
    -webkit-transform: scale(1) rotate(0);
            transform: scale(1) rotate(0);
  }
  40% {
    opacity: 0;
  }
}