.fcb-container {
    position: fixed;
    bottom: var(--fcb-offset-y, 24px);
    display: flex;
    flex-direction: column;
    gap: var(--fcb-gap, 14px);
    z-index: 99999;
}
.fcb-container.fcb-bottom-right { right: var(--fcb-offset-x, 24px); }
.fcb-container.fcb-bottom-left  { left:  var(--fcb-offset-x, 24px); }

.fcb-button {
    display: flex;
    align-items: center;
    justify-content: center;
    width: var(--fcb-size, 56px);
    height: var(--fcb-size, 56px);
    border-radius: 50%;
    background: var(--fcb-bg, #333);
    color: var(--fcb-icon, #fff);
    box-shadow: 0 4px 12px rgba(0, 0, 0, .2);
    text-decoration: none;
    transition: transform .15s ease, box-shadow .15s ease;
}
.fcb-button:hover,
.fcb-button:focus,
.fcb-button:active {
    /* Lock the icon colour so the host theme's a:hover colour can't bleed in. */
    color: var(--fcb-icon, #fff);
    transform: scale(1.08);
    box-shadow: 0 6px 16px rgba(0, 0, 0, .28);
}
.fcb-button svg {
    width: 55%;
    height: 55%;
    fill: currentColor;
    display: block;
}

@media (max-width: 480px) {
    .fcb-button {
        width: calc(var(--fcb-size, 56px) * .85);
        height: calc(var(--fcb-size, 56px) * .85);
    }
}