.wahc-button {
  position: fixed;
  right: calc(20px + env(safe-area-inset-right, 0px));
  bottom: calc(20px + env(safe-area-inset-bottom, 0px));
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: #fff;
  box-shadow: 0 4px 18px rgb(0 0 0 / 20%);
  transition: transform .2s ease, box-shadow .2s ease;
}
.wahc-button img { display: block; width: 60px; height: 60px; }
.wahc-button:hover { transform: translateY(-3px); box-shadow: 0 6px 22px rgb(0 0 0 / 28%); }
.wahc-button:focus-visible { outline: 3px solid #0a1f38; outline-offset: 4px; }
@media (max-width: 600px) {
  .wahc-button { right: calc(16px + env(safe-area-inset-right, 0px)); bottom: calc(16px + env(safe-area-inset-bottom, 0px)); width: 56px; height: 56px; }
  .wahc-button img { width: 52px; height: 52px; }
}
@media (prefers-reduced-motion: reduce) { .wahc-button { transition: none; } .wahc-button:hover { transform: none; } }