.md-header {              /* or whatever the actual header wrapper class is */
  position: relative;
  height: 60px;
  background-color: transparent;
  background-image: linear-gradient(rgba(255, 255, 255, 0.7), rgba(255, 255, 255, 0.7)),
		    url('/dad-site-test/assets/header-dad.jpg');
  background-size: cover;
  background-position: center;
}

.md-header__donate {
  position: absolute;   /* or flex-based, depending on your header's layout */
  right: 1rem;
  top: 50%;
  transform: translateY(-50%);
  padding: 0.4rem 0.8rem;
  border-radius: 4px;
  background: var(--md-primary-fg-color, #4051b5);
  color: white;
  text-decoration: none;
  font-size: 0.7rem;
  z-index: 2;
}