/* Единая кнопка «назад» во всех экспериментах */
.back-button {
  position: fixed;
  top: 20px;
  left: 20px;
  z-index: 310;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.07);
  border: none;
  color: rgba(250, 250, 250, 0.55);
  text-decoration: none;
  transition: background-color 0.15s ease, color 0.15s ease;
}

.back-button:hover {
  background: rgba(255, 255, 255, 0.1);
  color: #fafafa;
}

.back-button__icon {
  display: block;
  flex-shrink: 0;
}

html[data-theme="light"] .back-button,
body.scroll-theme-light .back-button {
  background: #f4f4f4;
  color: rgba(13, 13, 13, 0.6);
}

html[data-theme="light"] .back-button:hover,
body.scroll-theme-light .back-button:hover {
  background: #f1f1f1;
  color: #0d0d0d;
}

@media (max-width: 767px) {
  .back-button {
    top: 16px;
    left: 16px;
  }
}