css-animation css

* {
    margin: 0 auto;
    padding: 0;
    list-style: none;
    box-sizing: border-box;
}

#visual {
    width: 100%;
    height: 600px;
    float: left;
    position: relative;
    overflow: hidden;
}

@keyframes slide {
    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%; }
    95% { margin-left:-300%; }
    100% { margin-left:0; }
}

.imgslide {
    width: 400%;
    height: 600px;
    float: left;
    position: relative;
    transition: all 0.5s;
}



.imgslide li {
    width: 25%;
    height: 600px;
    float: left;
    background-size: cover;
    background-position: center;
}

.imgslide li:nth-child(1) {
    background-image: url("../../images/1.jpg");
}

.imgslide li:nth-child(2) {
    background-image: url("../../images/2.jpg");
}

.imgslide li:nth-child(3) {
    background-image: url("../../images/3.jpg");
}

.imgslide li:nth-child(4) {
    background-image: url("../../images/4.jpg");
}

.btns {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: #FFF;
    color: #000;
    text-align: center;
    line-height: 50px;
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    display: block;
    z-index: 999;
}

.btns-left {
    left: 10px;
}
.btns-left::before {
    content: "<";
}
.btns-right {
    right: 10px;
}
.btns-right::before {
    content: ">";
}

.btns-right:focus + .imgslide {
    animation: 2s slide1 forwards;
}

label{
    width: 10px;
    height: 10px;
    background-color: #000
}

#s1:checked ~ .imgslide{left: 0}
#s2:checked ~ .imgslide{left: -100%}
#s3:checked ~ .imgslide{left: -200%}
#s4:checked ~ .imgslide{left: -300%}