.sjb-turnstile {
    width: 100%;
    max-width: 100%;
    margin: 1em 0;
    box-sizing: border-box;
    container-type: inline-size;
    overflow: hidden;
}

/* El widget nace a 300px y se escala al ancho del formulario. */
.sjb-turnstile .cf-turnstile {
    width: 300px !important;
    min-width: 300px !important;
    max-width: none !important;
    height: 65px;
    transform: scale(calc(100cqw / 300px));
    transform-origin: top left;
    margin-bottom: calc((65px * 100cqw / 300px) - 65px);
}