.aviso {
    padding: 12px 20px;
    margin: 15px auto;
    border-left: 6px solid gray;
    border-radius: 5px;
    width: fit-content;
    font-family: sans-serif;
    font-size: 16px;
    animation: aparecer 0.3s ease-out;
}

.sucesso {
    background-color: #d4edda;
    border-color: #28a745;
    color: #155724;
}

.erro {
    background-color: #f8d7da;
    border-color: #dc3545;
    color: #721c24;
}

@keyframes desaparecer {
    to { opacity: 0; transform: translateY(-20px); }
}

@keyframes aparecer {
    from { opacity: 0; transform: translateY(20px); }
    to   { opacity: 1; transform: translateY(0); }
}