* {box-sizing: border-box;}
body {margin:0;}
img {width:100%;}
.slideshow {
  width:80%;
  margin:auto;
  display:flex;
  align-items:center;
}
.slideshow .slide {
  flex:80%;
}
.slideshow .slideimg {
  transition: 1s;
    animation: fadeIn; /* referring directly to the animation's @keyframe declaration */
  animation-duration: 2s; /* don't forget to set a duration! */
}
.arrow {
  font-size:60px;
  padding:10px;
  cursor: pointer;
}