.code-block {
  position: relative;
}

.copy-btn {
  position: absolute;
  top: 6px;
  right: 6px;
  padding: 4px 8px;
  background: #444;
  color: #fff;
  border: none;
  font-size: 0.8em;
  border-radius: 4px;
  cursor: pointer;
  opacity: 0.7;
}

.copy-btn:hover {
  opacity: 1;
}

pre {
  background: #fafafa;
  border-radius: 6px;
}

pre code.hljs {
  line-height: 1.5;
  font-size: 14.5px;
}