.wp-block-button.is-style-outline
  > .wp-block-button__link:not(.has-text-color, .has-background):hover {
  background-color: transparent;
  color: var(--wp--preset--color--primary);
  border-color: var(--wp--preset--color--primary);
}

.wp-block-button .wp-block-button__link[style*="background-color"]:hover {
  opacity: 0.8;
}