.encadre-obligatoire {
    padding: 5px;
    border: 1px solid #dc3545;
    border-radius: 10px;
}

.was-validated .liste-une-seulement:invalid + .select2 .select2-selection,
.was-validated .liste-une-seulement:valid + .select2 .select2-selection {
    width: 100%;
    min-height: calc(1.5em + 0.75rem + 2px);
    padding: 0.375rem 0.75rem;
    font-family: inherit;
    font-size: 1rem;
    font-weight: 400;
    line-height: 1.5;
    color: #212529;
    background-color: #fff;
    border: 1px solid #ced4da;
    border-radius: 0.25rem;
    transition: border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
}

*:focus {
    outline: 0px;
}

.bordure-invalide {
    border: 1px solid #dc3545 !important;
    padding: 5px;
}

.bordure-valide {
    border: 1px solid #28a745 !important;
    padding: 5px;
}