@keyframes animateBackground {
    from { background-position: 0 0; }
    to { background-position: 100% 0; }
}
header{
    width:100%;
    height:636px;
    background-image: url("gal.jpg");
    //background-position: 0 0;
    background-repeat: repeat-x;

    animation: animateBackground 40s linear infinite;
}
body{
    margin: 0;
    background: lightgray;
}
.course{
    margin-left: 220px;
    margin-bottom: 50px;
    height:450px;
    width: 900px;
    border-radius: 10%;
    transition: border-radius 1s;

}
.course:hover{
    border-radius: 50%;
    transition: border-radius 0.8s;
    filter: brightness(30%);
}
h3{
    display:inline-block;
    position: relative;
    bottom: 290px;
    right:550px;
    width: 200px;
    height: 24px;
    text-align: center;
    background: dimgray;
    padding: 10px 3px;

}
a
{ font-weight: bold;
    color: whitesmoke;
    font-family: Bahnschrift;
}
fieldset span{
    display: inline-block;
    width: 120px;
    text-align: right;
    margin: 20px;
    font-weight: bold;
    font-family: "Cooper Black";
}
fieldset{
    margin: 30px 250px;
    width: 800px;
    border: red dotted 2px;
}
legend{
    padding:10px;
    border: black solid 2px;
    font-weight: bold;
    font-family: "Cooper Black";
}
input,textarea{
    padding: 5px 8px;
    border: black solid 1px;
}
aside {
    height:600px;
    width: 300px;
    background: whitesmoke;
    position:relative;
    right:301px;
    transform: translateX(0);
    transition: transform 2.5s;
    border-radius: 3%;
}
details{
    padding: 10px;
    font-family: Bahnschrift;
    font-weight: bold;
    font-size: large;
}

#hovering:hover aside{
    transform: translateX(300px);
    transition: transform 2.5s;
}
li{
    list-style: none;
}