CSS rotated pictures don't appear one after another, and very soon.

my css broadcast speed is very fast, even though I have set up 60 seconds. I just learned HTML+css and soon encountered a lot of problems in doing a web page. Please take a look at this site boss. Thank you
html:

.
<div class="c1">
      <ul>
          <li><a href=""><img src="image/lunbo1.jpg" alt=""></a></li>
          <li><a href=""><img src="image/lunbo2.jpg" alt=""></a></li>
          <li><a href=""><img src="image/lunbo3.jpg" alt=""></a></li>
          <li><a href=""><img src="image/lunbo4.jpg" alt=""></a></li>
          <li><a href=""><img src="image/lunbo5.jpg" alt=""></a></li>
          <li><a href=""><img src="image/lunbo6.jpg" alt=""></a></li>
          <li><a href=""><img src="image/lunbo7.jpg" alt=""></a></li>
      </ul>          
</div>

css:

.c1{
    width:1520px ;
    height:330px ;
    overflow: hidden;
    margin-top: 20px;
}
.c1 ul li img{
    width: 1520px;
    height: 330px;
}
.c1 ul{
    width: 20000px;
}
.c1 ul li{
    display: inline-block;
    animation: myf 60s ease-in-out infinite alternate;
}
@keyframes myf {
    0% {margin-left: 0px;}
    14% {margin-left: -1520px;}
    28% {margin-left: -3040px;}
    42% {margin-left: -4560px;}
    56% {margin-left: -6080px;}
    70% {margin-left: -7600px;}
    84% {margin-left: -9120px;}
}
Jul.30,2021

.c1{
        width:1520px ;
        height:330px ;
        overflow: hidden;
        margin-top: 20px;
    }
    .c1 ul li img{
        width: 1520px;
        height: 330px;
        border: 1px -sharpddd solid;
    }
    .c1 ul{
        width: 20000px;
        white-space: nowrap;
    }
    .c1 ul{
        animation: myf 60s linear infinite alternate;
    }
    .c1 ul li{        
        display: inline-block;
    }
    @keyframes myf {
        0% {margin-left: 0px;}
        14% {margin-left: -1520px;}
        28% {margin-left: -3040px;}
        42% {margin-left: -4560px;}
        56% {margin-left: -6080px;}
        70% {margin-left: -7600px;}
        100% {margin-left: -9120px;}
    }
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