docs/_static/copybutton.css

/* Copy-to-clipboard button styles */
div.highlight {
  position: relative;
}

button.copybutton {
  position: absolute;
  top: 0.4em;
  right: 0.4em;
  padding: 0.3em 0.4em;
  background: var(--color-background-secondary, #f0f0f0);
  border: 1px solid var(--color-foreground-border, #ccc);
  border-radius: 4px;
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.2s, background 0.15s;
  line-height: 1;
  color: var(--color-foreground-secondary, #555);
}

div.highlight:hover button.copybutton,
button.copybutton:focus {
  opacity: 1;
}

button.copybutton:hover {
  background: var(--color-background-hover, #e0e0e0);
}

button.copybutton.copied {
  color: var(--color-brand-primary, #2980b9);
  opacity: 1;
}

button.copybutton svg {
  display: block;
  pointer-events: none;
  fill: currentColor;
}