#aton-whatsapp {
    position: fixed;
    right: max(24px, env(safe-area-inset-right));
    bottom: calc(24px + env(safe-area-inset-bottom));
    left: auto;
    z-index: 9990;
    display: flex;
    align-items: center;
    justify-content: center;
    box-sizing: border-box;
    width: 60px;
    height: 60px;
    padding: 0;
    margin: 0;
    border: 1px solid #e2f6e9;
    border-radius: 50%;
    background: #fff;
    box-shadow: 0 4px 18px rgb(0 0 0 / 20%);
    text-decoration: none;
    transition: transform 160ms ease, box-shadow 160ms ease;
}
#aton-whatsapp img { display: block; width: 38px; height: 38px; max-width: none; margin: 0; }
#aton-whatsapp:hover { transform: translateY(-2px); box-shadow: 0 6px 22px rgb(0 0 0 / 25%); }
#aton-whatsapp:focus-visible { outline: 3px solid #075e54; outline-offset: 4px; }
@media (max-width: 600px) {
    #aton-whatsapp { right: max(16px, env(safe-area-inset-right)); bottom: calc(16px + env(safe-area-inset-bottom)); width: 56px; height: 56px; }
    #aton-whatsapp img { width: 36px; height: 36px; }
}
@media (prefers-reduced-motion: reduce) { #aton-whatsapp { transition: none; } }