<style>
    #button{
        position: fixed;
        left:0;
        top:0;
        background-color: black;
        color: white;
        width: 10%;
        height:10%;
    }

    #trigger:target + animated{
        left: 50%;
    }

    #animated{
        position: fixed;
        left: 0;
        top: 10%;
        width: 10%;
        height: 10%;
        background-color: blue;
        transition: 1s;
    }


</style>

<div id="button">
    <a href="#trigger">click here</a>
</div>

<div id="animated"></div>