@keyframes pageupFadeIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.pageup {
    display: flex;
    align-items: center;
    justify-content: center;
    position: fixed;
    bottom: 24px;
    right: 24px;
    width: 48px;
    height: 48px;
    background: var(--color-surface);
    border-radius: 50%;
    box-shadow: var(--shadow-lg, 0 4px 14px rgba(32, 45, 40, 0.12));
    border: 1px solid var(--color-border);
    cursor: pointer;
    transition: var(--transition);
    z-index: 100;
    animation: pageupFadeIn 0.35s ease;
}

.pageup:hover {
    background: var(--color-primary);
    border-color: var(--color-primary);
    transform: translateY(-2px);
}

.pageup img {
    width: 24px;
    height: 24px;
}

.pageup:hover img {
    filter: brightness(0) invert(1);
}