.slider{
    width: 100%;
    margin: auto;
    overflow: hidden;

}

.slider ul{
    display:flex;
    padding: 0;
    width: 400%;

    animation: cambio 30s infinite alternate;
    animation-timing-function:ease-in;
}

.slider li {
    width:100%;
    list-style: none;
}

.slider img {
    width:100vw;
    display:block;
    margin:auto;
    
}

@keyframes cambio {
    0% {margin-left: 0;}
    20% {margin-left:0;} 

    25% {margin-left:-100%;} 
    45% {margin-left:-100%;} 

    50% {margin-left:-200%;} 
    70% {margin-left:-200%;} 

    75% {margin-left:-300%;} 
    100% {margin-left:-300%;} 
}