#wa-fab {
    position: fixed;
    right: 20px;
    bottom: 20px;
    z-index: 1050;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background-color: #25d366;
    color: #fff;
    font-size: 32px;
    box-shadow: 0 6px 20px rgba(0,0,0,0.25);
    transition: transform .2s ease, box-shadow .2s ease;
}

#wa-fab:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.3);
    text-decoration: none;
    color: #fff;
}

#wa-fab::after {
    content: "";
    position: absolute;
    inset: 0;
    border-radius: 50%;
    border: 2px solid rgba(37,211,102,.35);
    animation: pulse 1.8s ease-out infinite;
}

@keyframes pulse {
    0%   { transform: scale(1); opacity: .9; }
    70%  { transform: scale(1.4); opacity: 0; }
    100% { transform: scale(1.4); opacity: 0; }
}

@media (max-width: 576px) {
    #wa-fab {
        width: 50px;
        height: 50px;
        font-size: 26px;
        right: 15px;
        bottom: 15px;
    }
}

@media (max-width: 768px) {
    #wa-fab {
        width: 54px;
        height: 54px;
        font-size: 28px;
        right: 16px;
        bottom: 16px;
    }
}

@media (min-width: 1200px) {
    #wa-fab {
        width: 64px;
        height: 64px;
        font-size: 34px;
    }
}