/* Back-to-top button — injected by help-center.js */
#hc-back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--hc-primary);
  color: #fff;
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 16px rgba(91, 33, 182, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.25s ease, transform 0.25s ease;
  pointer-events: none;
  z-index: 999;
}

#hc-back-to-top.is-visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

#hc-back-to-top:hover {
  background: var(--hc-primary-dark);
  transform: translateY(-2px);
}

/* Copy-link button injected on article headings */
.hc-copy-link-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-left: 8px;
  padding: 3px 5px;
  background: none;
  border: none;
  border-radius: 4px;
  color: var(--hc-text-muted);
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.2s, color 0.2s, background 0.2s;
  vertical-align: middle;
}

h2:hover .hc-copy-link-btn,
h3:hover .hc-copy-link-btn {
  opacity: 1;
}

.hc-copy-link-btn:hover {
  color: var(--hc-primary);
  background: var(--hc-primary-light);
}

/* Sticky header shadow */
.hc-header--scrolled {
  box-shadow: 0 1px 16px rgba(15, 23, 42, 0.1) !important;
}