.bc-support {
  display: grid;
  width: 3.75rem;
  height: 3.75rem;
  place-items: center;
  border: 2px solid rgba(255,255,255,.92);
  border-radius: 50%;
  color: #fff;
  background: #25d366;
  box-shadow: 0 12px 28px rgba(18,140,70,.3);
  filter: none;
}

.bc-support svg {
  display: block;
  width: 2.15rem;
  height: 2.15rem;
  fill: currentColor;
}

.bc-support:hover,
.bc-support:focus-visible {
  color: #fff;
  background: #1fbd59;
  box-shadow: 0 16px 34px rgba(18,140,70,.4);
  transform: translateY(-4px) scale(1.04);
}

.bc-support:active { transform: translateY(-1px) scale(.98); }

@media (max-width: 520px) {
  .bc-support { right: .85rem; bottom: .85rem; width: 3.45rem; height: 3.45rem; }
  .bc-support svg { width: 1.95rem; height: 1.95rem; }
}