.slider {
 overflow: hidden;
 width: 100vw;
 height: 100vh;
 position: relative;
}
 
.slider .slide {
 position: absolute;
 top: 0;
 left: 0;
 width: 100%;
 height: 100%;
 background-size: cover;
 background-position: center;
 animation: slider 12.5s infinite;
}
 
.slider .slide:nth-child(1) {
   background-image: url('https://images.unsplash.com/photo-1595356700395-6f14b5c1f33f?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1000&q=80');
   animation-delay: 0s;
}

.slider .slide:nth-child(2) {
   background-image: url('https://images.unsplash.com/photo-1591019052241-e4d95a5dc3fc?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1000&q=80');
   animation-delay: -2.5s;
}

.slider .slide:nth-child(3) {
   background-image: url('https://images.unsplash.com/photo-1543373014-cfe4f4bc1cdf?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1000&q=80');
   animation-delay: -5s;
}

.slider .slide:nth-child(4) {
   background-image: url('https://images.unsplash.com/photo-1517430554953-a5ba4678fe85?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1000&q=80');
   animation-delay: -7.5s;
}

.slider .slide:nth-child(5) {
   background-image: url('https://images.unsplash.com/photo-1583161178154-c362b3459d29?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1000&q=80');
   animation-delay: -10s;
}

@keyframes slider {
 0%, 16%, 100% {
   transform: translateX(0);
   animation-timing-function: ease;
 }
 20% {
   transform: translateX(-100%);
   animation-timing-function: step-end;
 }
 96% {
   transform: translateX(100%);
   animation-timing-function: ease;
 }
}