So erzielen Sie mit reinem CSS den Animationseffekt einer dreidimensionalen Schaltfläche mit metallischem Glanz (Quellcode beigefügt)

<div class="box">BUTTON</div>

html, body {
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: skyblue;
}

.box {
    background: linear-gradient(to right, gold, darkorange);
    color: white;
    --width: 250px;
    --height: calc(var(--width) / 3);
    width: var(--width);
    height: var(--height);
    text-align: center;
    line-height: var(--height);
    font-size: calc(var(--height) / 2.5);
    font-family: sans-serif;
    letter-spacing: 0.2em;
    border: 1px solid darkgoldenrod;
    border-radius: 2em;
}

.box {
    transform: perspective(500px) rotateY(-15deg);
    text-shadow: 6px 3px 2px rgba(0, 0, 0, 0.2);
    box-shadow: 2px 0 0 5px rgba(0, 0, 0, 0.2);
}

.box:hover {
    transform: perspective(500px) rotateY(15deg);
    text-shadow: -6px 3px 2px rgba(0, 0, 0, 0.2);
    box-shadow: -2px 0 0 5px rgba(0, 0, 0, 0.2);
}

.box {
    transition: 0.5s;
}

.box {
    position: relative;
}

.box::before {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background: linear-gradient(to right, transparent, white, transparent);
    left: 0;
}

.box::before {
    left: -100%;
    transition: 0.5s;
}

.box:hover::before {
    left: 100%;
}

.box {
    overflow: hidden;
}