.top-btn {
  position: fixed;
  right: 20px;
  bottom: 24px;
  width: 48px;
  height: 48px;
  border-radius: 999px;
  border: 1px solid rgba(0, 0, 0, 0.08);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(140%) blur(8px);
  -webkit-backdrop-filter: saturate(140%) blur(8px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.12);
  color: #5a3a22;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.04em;
  cursor: pointer;
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  transition: opacity 0.2s ease, transform 0.2s ease;
  opacity: 0;
  padding: 0;
}
.top-btn.visible {
  display: inline-flex;
  opacity: 1;
}
.top-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.16);
}
.top-btn svg {
  width: 18px;
  height: 18px;
  stroke: currentColor;
  fill: none;
  stroke-width: 2.4;
  stroke-linecap: round;
  stroke-linejoin: round;
}
@media (max-width: 480px) {
  .top-btn {
    right: 16px;
    bottom: 20px;
    width: 44px;
    height: 44px;
  }
}