/* ==========================================================================
   Plovouci tlacitko "zpet nahoru"
   --------------------------------------------------------------------------
   Markup: footer.php (za </footer>), chovani: inc/features/scroll-to-top.php.
   Drive sedelo v components/footer.css, i kdyz s patickou nesouvisi - plave
   nad celou strankou.

   POZOR na skryty stav. Viditelnost prepina JS atributem [hidden], jenze
   display:flex nize prebiji UA pravidlo [hidden]{display:none}. Tlacitko proto
   drive zustavalo v layoutu - neviditelne (opacity:0), ale porad klikatelne,
   takze v pravem dolnim rohu ukusovalo kliky na kazde strance. Skryva ho az
   visibility + pointer-events; obojí se da animovat spolu s opacity, takze
   prechod zustal zachovany.
   ========================================================================== */

.scroll-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 50px;
  height: 50px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  z-index: 1000;

  /* skryty stav */
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(20px);
  transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s;
}

.scroll-to-top:not([hidden]) {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateY(0);
}

.scroll-to-top:hover,
.scroll-to-top:focus-visible {
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.25);
}

.scroll-to-top svg {
  color: #fff;
}

@media (max-width: 768px) {
  .scroll-to-top {
    bottom: 1rem;
    right: 1rem;
    width: 45px;
    height: 45px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .scroll-to-top {
    transition: none;
  }
}