.fbt-button{--fbt-size: 48px;--fbt-offset-b: 24px;--fbt-offset-s: 24px;--fbt-bg: #111;--fbt-icon: #fff;--fbt-hover-bg: #000;--fbt-hover-icon: #fff;--fbt-opacity: 0.9;position: fixed;z-index: 9998;width: var(--fbt-size);height: var(--fbt-size);padding: 0;margin: 0;border: 0;background: var(--fbt-bg);color: var(--fbt-icon);cursor: pointer;opacity: 0;visibility: hidden;pointer-events: none;transition: opacity 0.25s ease,transform 0.25s ease,background-color 0.2s ease,color 0.2s ease;box-shadow: 0 4px 12px rgba(0,0,0,0.18);display: inline-flex;align-items: center;justify-content: center;line-height: 0}.fbt-button:focus-visible{outline: 2px solid currentColor;outline-offset: 3px}.fbt-button svg{width: 55%;height: 55%;display: block}.fbt-button:hover{background: var(--fbt-hover-bg);color: var(--fbt-hover-icon)}.fbt-button.is-visible{opacity: var(--fbt-opacity);visibility: visible;pointer-events: auto}.fbt-button.is-visible:hover{opacity: 1}.fbt-pos-bottom-right{right: var(--fbt-offset-s);bottom: var(--fbt-offset-b)}.fbt-shape-circle{border-radius: 50%}.fbt-anim-fade{}.fbt-anim-slide.is-visible{transform: translateY(0)}.fbt-anim-scale.is-visible{transform: scale(1)}@media (max-width: 767px){.fbt-hide-mobile{display: none !important}}@media (prefers-reduced-motion: reduce){.fbt-button{transition: opacity 0.15s linear,background-color 0.2s ease,color 0.2s ease}}