.fmc-mess-float {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, #00C6FF, #0072FF);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 15px rgba(0, 114, 255, 0.4);
    z-index: 999999;
    /* ĐÃ NÂNG CẤP: Thêm 'bottom 0.3s ease' để lúc JS nhấc nút lên/hạ xuống nó trượt cực mượt */
    transition: transform 0.3s ease, bottom 0.3s ease; 
    text-decoration: none !important;
    animation: fmc-pulse-mess 2s infinite;
}
.fmc-mess-float:hover { transform: scale(1.1); }
.fmc-mess-float svg { width: 34px; height: 34px; fill: #ffffff; }

@keyframes fmc-pulse-mess {
    0% { box-shadow: 0 0 0 0 rgba(0, 114, 255, 0.5); }
    70% { box-shadow: 0 0 0 15px rgba(0, 114, 255, 0); }
    100% { box-shadow: 0 0 0 0 rgba(0, 114, 255, 0); }
}

@media (max-width: 767px) {
    .fmc-mess-float {
        bottom: 20px;
        right: 20px;
        width: 50px;
        height: 50px;
    }
    
    .fmc-mess-float svg {
        width: 28px;
        height: 28px;
    }
}