/* Reset border untuk input group */
    .input-group:not(.has-validation) > .form-control:not(:last-child).is-invalid,
    .input-group:has(.form-control.is-invalid) {
        border-color: #dc3545;
    }
    
    /* Atur border untuk input di dalam input-group */
    .input-group .form-control.is-invalid {
        border-color: #dc3545 !important;
        border-right-color: #dee2e6 !important; /* Warna border default Bootstrap */
        box-shadow: none !important;
    }
    
    /* Atur border untuk input-group-text (icon mata) */
    .input-group .form-control.is-invalid + .input-group-text {
        border-color: #dc3545 !important;
        border-left-color: #dee2e6 !important;
    }
    
    /* Atau versi lebih sederhana: border solid di seluruh input-group */
    .input-group:has(.form-control.is-invalid) {
        border: 1px solid #dc3545;
        border-radius: 0.375rem;
    }
    
    .input-group:has(.form-control.is-invalid) .form-control,
    .input-group:has(.form-control.is-invalid) .input-group-text {
        border: none !important;
        box-shadow: none !important;
    }
    
    /* Hover effect tetap normal */
    .input-group:has(.form-control.is-invalid):hover {
        border-color: #b02a37;
    }