.alrt_success_bx {
        width: 50% !important;
        right: 0;
        height: auto!important;
    }

    .alrt_success_bx {
        position: relative;
        width: 300px;
        padding: 20px;
        background-color: #4CAF50; /* Green */
        color: white;
        opacity: 0;
        transition: opacity 0.6s; /* 600ms to fade in */
        right: -100%; /* Start position */
        animation: slide-in 0.5s forwards; /* Slide in */
    }   

    @keyframes slide-in {
        from {
            right: -100%;
            opacity: 0;
        }
        to {
            right: 0;
            opacity: 1;
        }
    }