/* ==========================================================================
   Navigation: runde Icon-Buttons (.nav) und Zurück-Pfeil (.nav-back)
   Figma-Komponente "NavIcon". Gemeinsam für Stream- und Album-Seiten.
   ========================================================================== */

:root {
  --back-offset: clamp(16px, 4.9vh, 50px);   /* Zurück-Pfeil: Abstand oben/links (Figma: 50px) */
}

/* Chevron-Navigation */
.nav {
  position: fixed;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  padding: 0;
  box-sizing: border-box;
  border: 1px solid transparent;
  border-radius: 50%;
  background: none;
  color: #fff;
  opacity: 0.5;
  cursor: pointer;
  transition: opacity 0.2s ease, border-color 0.2s ease, background-color 0.2s ease, color 0.2s ease;
  -webkit-tap-highlight-color: transparent;
}
.nav:hover,
.nav:focus-visible {
  opacity: 1;
  border-color: #fff;
  background: rgba(255, 255, 255, 0.5);
}
.nav[hidden] { display: none; }
.nav img {
  display: block;
  width: 24px;
  height: 24px;
}
.nav-back {
  width: 42px;
  height: 42px;
  opacity: 1;
  border: 0;
  background: none;                 /* Figma "NavIcon": default = nur der weiße Pfeil */
  top: calc(env(safe-area-inset-top, 0px) + var(--back-offset));
  left: calc(env(safe-area-inset-left, 0px) + var(--back-offset));
}
.nav-back:hover,
.nav-back:focus-visible { background: #fff; }   /* hover = weißer Kreis, dunkler Pfeil */

/* Das Icon ist weiß exportiert; im Hover auf #1e1e1e umgefärbt */
.nav-back:hover img,
.nav-back:focus-visible img { filter: brightness(0) invert(0.118); }