.app-alert {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    min-width: 280px;
    max-width: 90%;
    padding: 12px 16px;
    border-radius: 6px;
    font-size: 14px;
    text-align: center;
    z-index: 9999;
    display: none;
    box-shadow: 0 6px 20px rgba(0,0,0,0.15);
    animation: fadeIn 0.3s ease;
}

.app-alert-success {
    background-color: #d1e7dd;
    color: #0f5132;
    border: 1px solid #badbcc;
}

.app-alert-danger {
    background-color: #f8d7da;
    color: #842029;
    border: 1px solid #f5c2c7;
}

.app-alert-warning {
    background-color: #fff3cd;
    color: #664d03;
    border: 1px solid #ffecb5;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translate(-50%, -10px);
    }
    to {
        opacity: 1;
        transform: translate(-50%, 0);
    }
}