#principal {
    padding: 40px;
    width: 100vw;
    display: flex;
    justify-content: center;
    align-items: center;
}
.card {
    width: auto;
    align-items: center;
}

img {
    display: block;
    margin-left: auto;
    margin-right: auto;
    width: 50%;
    height: auto;
    padding: 10px;
}

.fila-modificable {
    border: 4px solid gray !important;
}

.fila-modificable td {
    background-color: orange;
}

.error {
    color: red;
}

a {
    text-decoration: none; 
    color: black;
}

input[type="number"] {
    width: 100px;
}