.message-input.is-stamp-hidden {
  grid-template-columns: minmax(0, 1fr);
}

.message-input.is-stamp-hidden .send-box,
.message-input.is-stamp-hidden .message-cost {
  grid-column: 1;
}

.message-input.is-stamp-hidden .stamp-button {
  display: none !important;
}