/* beyond-bubbles – "Nach oben"-Button
   Position/Groesse bei Bedarf hier anpassen (bei beiden Elementen gleich). */

/* Der Button selbst: durchsichtig, nur der weisse Pfeil */
#bb-nach-oben,
#bb-nach-oben-blase {
  position: fixed;
  right: 18px;
  bottom: 18px;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  /* versteckt, bis heruntergescrollt wurde */
  opacity: 0;
  visibility: hidden;
  translate: 0 10px;
  transition: opacity 0.4s ease, translate 0.4s ease, visibility 0s linear 0.4s, scale 0.2s ease;
}

#bb-nach-oben {
  z-index: 99997;
  padding: 0;
  border: 0;
  background: transparent;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

/* Die gemalte Blase dahinter, mischt sich mit dem Untergrund */
#bb-nach-oben-blase {
  z-index: 99996;
  pointer-events: none;
  background: var(--bb-oben-blase) center / contain no-repeat;
  mix-blend-mode: multiply;
}

#bb-nach-oben.bb-sichtbar,
#bb-nach-oben.bb-sichtbar + #bb-nach-oben-blase {
  opacity: 1;
  visibility: visible;
  translate: 0 0;
  transition: opacity 0.4s ease, translate 0.4s ease, visibility 0s linear 0s, scale 0.2s ease;
}

#bb-nach-oben:hover,
#bb-nach-oben:focus-visible,
#bb-nach-oben:hover + #bb-nach-oben-blase,
#bb-nach-oben:focus-visible + #bb-nach-oben-blase {
  scale: 1.08;
}

#bb-nach-oben:focus-visible {
  outline: 2px solid #000;
  outline-offset: 3px;
}

#bb-nach-oben svg {
  margin-top: -2px; /* Pfeil optisch zentrieren */
}

@media (prefers-reduced-motion: reduce) {
  #bb-nach-oben,
  #bb-nach-oben-blase,
  #bb-nach-oben.bb-sichtbar,
  #bb-nach-oben.bb-sichtbar + #bb-nach-oben-blase {
    translate: none;
    transition: opacity 0.2s ease, visibility 0s linear 0.2s;
  }
}