.em-form-challenge {
  display: grid;
  grid-template-columns: minmax(0, 218px) auto;
  align-items: center;
  justify-content: start;
  gap: .55rem .7rem;
  padding: clamp(.7rem, 2vw, 1rem);
  border: 1px solid var(--em-rule, #cbd8d9);
  border-radius: 8px;
  background: var(--em-canvas, #f4f7f7);
}
.em-form-challenge img { border: 1px solid var(--em-rule, #cbd8d9); border-radius: 5px; }
.em-form-challenge label,.em-form-challenge input[name="captcha"] { grid-column: 1 / -1; }
.em-form-challenge input[name="captcha"] { max-width: 16rem; }
.em-form-challenge button:not([hidden]) {
  min-height: 44px;
  color: var(--em-ink, #173c57);
  background: var(--em-paper, #fff);
  border: 1px solid var(--em-rule, #cbd8d9);
  border-radius: 5px;
  padding: .42rem .65rem;
  font: inherit;
  font-size: .82rem;
  cursor: pointer;
}
.em-form-challenge button:disabled { opacity: .55; }