.form-turnstile {
  width: 100%;
  max-width: 100%;
  overflow: hidden;
}

/* Turnstile is 300px wide; scale down on mobile and compensate layout box */
@media (max-width: 639px) {
  .form-turnstile .cf-turnstile {
    --turnstile-scale: min(1, calc((100vw - 7rem) / 300));
    transform: scale(var(--turnstile-scale));
    transform-origin: left top;
    width: 300px !important;
    margin-right: calc(300px * (var(--turnstile-scale) - 1));
    margin-bottom: calc(65px * (var(--turnstile-scale) - 1));
  }
}