.back-to-top {
    position: fixed;
    bottom: 50px;
    right: 20px;
    width: 60px;
    height: 60px;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease, transform 0.3s ease;
    z-index: 990;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    border: none;
    background: transparent;
}

.back-to-top img {
    width: 100%;
    height: auto;
    object-fit: contain;
    filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.2));
}

.back-to-top.show {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0);
}

.back-to-top:hover img {
    transform: scale(1.05);
    transition: transform 0.2s ease;
}