.fluct-container {
    display: flex;
    justify-content: center; /* horisontell centrering */
    align-items: center; /* vertikal centrering */
    height: 100vh; /* om du vill fylla hela skärmen */
}

.fluct {
    width: 10vw;
    height: 10vw;
    background-color: #333;
    margin: 5vw auto;
    animation: sk-rotateplane 1.2s infinite ease-in-out;
}

@keyframes sk-rotateplane {
    0% {
        transform: perspective(120px) rotateX(0deg) rotateY(0deg);
    }

    50% {
        transform: perspective(120px) rotateX(-180.1deg) rotateY(0deg);
    }

    100% {
        transform: perspective(120px) rotateX(-180deg) rotateY(-179.9deg);
    }
}