blog.victor-hery.com/theme/static/css/code-copy.css

.codecopy {
  position: relative;
  overflow: visible;

  & button.codecopy-btn {
    font-size: rfs(0.9rem);
    box-shadow: none;
    min-height: initial;

    position: absolute;
    z-index: 1;

    right: 0;
    top: 0;
    background-color: #fe8019;
    padding: rfs(0.2rem);
    border: none;
    border-top-right-radius: var(--borderRadius);
    border-bottom-left-radius: var(--borderRadius);

    &:hover,
    &:focus {
      box-shadow: none;
    }
  }
}

/* Remove radus when inside liquid_tags.include_code */
figure.code
  > div.highlight:not(:first-child)
  > div.codecopy
  > button.codecopy-btn {
  border-top-right-radius: 0;
}