form {
    width: 450px;
    margin: auto;
    padding: 10px 20px;
    box-sizing: border-box;
    margin-top: 20px;
    border-radius: 10px;
    background: rgba(0,0,0,0.5);
}

.slider {
    width: 95%;
    margin: auto;
    overflow: hidden;
}
.slider ul {
    display: flex;
    padding: 0;
    width: 400%;
    animation: cambio 20s infinite;
}

.slider li {
    list-style: none;
}
#Boton {
    background: #31384A;
    color:#fff;
    font-size: 17px;
}
#Boton:hover {
    cursor: pointer;
}

.slider img {
    width: 100%;}

@keyframes cambio {
    0% {margin-left: 0%;}
    20% {margin-left: 0%;}
    
    25% {margin-left: -100%;}
    45% {margin-left: -100%;}
    
    50% {margin-left: -200%;}
    75% {margin-left: -200%;}
    
     80% {margin-left: -300%;}
    100% {margin-left: -300%;}
}



input, textarea {
    width: 100%;
    margin-bottom: 10px;
    padding: 7px;
    box-sizing: border-box;
    font-size: 17px;
    border: none;
}

textarea {
    max-width: 100%;
}


@media (max-width:786px) {
    form {
        width: 100%; 
    }
   
}

@media (min-width:1024px) {
    .slider {
    width:40%;
    margin: auto;
    overflow: hidden;
}