body {
    margin: 0;
}

.img-container {
    position: relative;
}

.img-map {
    width: 100%;
}

.stage-shape {
    background-color: transparent;
    border: dashed 0.1em rgba(255, 0, 0, 0.1);
    border-radius: 10%;
    box-shadow: 1em 1em 4em rgba(255, 0, 0, 0.1);
}

.stage-1 {
    position: absolute;
    top: 53%;
    left: 8%;
    width: 20%;
    height: 27%;
}

.stage-2 {
    position: absolute;
    top: 47%;
    left: 32.5%;
    width: 13.5%;
    height: 27%;
}

.stage-3 {
    position: absolute;
    top: 52%;
    left: 56%;
    width: 14%;
    height: 23%;
}

.stage-4 {
    position: absolute;
    top: 34.5%;
    left: 73%;
    width: 17%;
    height: 31%;
}

.stage-content > a {
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    text-decoration: none;
}

@property --placeholder-y {
    syntax: '<percentage>';
    inherits: true;
    initial-value: 0%;
}

@keyframes slide-up {
    from { --placeholder-y: -20%; }
    to { --placeholder-y: 0%; }
}

.current-stage {
    width: 4.5%;
    position: absolute;
    top: 49%;
    left: 16.5%;

    translate: 0 var(--placeholder-y);
    animation: slide-up 0.5s infinite alternate ease-in-out;
}