:root {
    --horizontal-accordion-right-height: 4vmin;
}
horizontal-accordion-right {
    position: fixed;
    right: 0;
    top: calc(50vh - var(--horizontal-accordion-right-height) / 2);
    height: var(--horizontal-accordion-right-height);
    width: var(--horizontal-accordion-right-height);
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: nowrap;
    z-index: 9999;
    cursor: pointer;
    transition: opacity 0.2s;
    opacity: 1;
}
horizontal-accordion-right:active {
    opacity: 0.5;
}
horizontal-accordion-right > * {
    height: calc(var(--horizontal-accordion-right-height) / 2);
    width: calc(var(--horizontal-accordion-right-height) / 2);
}