/* ===================================
   NAVIGATION
   Transparent über dem Hero, danach Glasleiste.
   .header--on-dark / --on-light folgt dem Untergrund unter dem Header.
   =================================== */

.header {
  position: fixed;
  inset: 0 0 auto;
  z-index: var(--z-header);
  height: var(--header-h);
  color: var(--ink-light);
  transition:
    background-color var(--dur-base) var(--ease-out),
    color var(--dur-base) var(--ease-out),
    transform 420ms var(--ease-out);
}

.header::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  opacity: 0;
  background-color: rgba(15, 17, 19, 0.78);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid rgba(242, 239, 234, 0.08);
  transition: opacity var(--dur-base) var(--ease-out), background-color var(--dur-base) var(--ease-out);
}

.header.scrolled::before {
  opacity: 1;
}

.header.header--on-light {
  color: var(--ink-dark);
}

.header.header--on-light::before {
  background-color: rgba(243, 241, 236, 0.84);
  border-bottom-color: rgba(21, 24, 27, 0.08);
}

/* Beim Herunterscrollen ausblenden, beim Hochscrollen zeigen */
.header.header--hidden {
  transform: translateY(-100%);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s-6);
  height: 100%;
}

.nav__logo {
  display: inline-flex;
  align-items: center;
  gap: var(--s-3);
  flex: none;
}

.nav__logo-img {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  box-shadow: 0 0 0 1px rgba(242, 239, 234, 0.22);
}

.nav__logo-text {
  font-family: var(--font-display);
  font-stretch: var(--display-stretch);
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.nav__logo-suffix {
  font-weight: 500;
  opacity: 0.6;
}

.nav__menu {
  display: flex;
  align-items: center;
  gap: clamp(var(--s-4), 2vw, var(--s-6));
}

.nav__link {
  position: relative;
  padding-block: var(--s-2);
  font-size: var(--t-small);
  font-weight: 500;
  opacity: 0.86;
  transition: opacity var(--dur-fast) var(--ease-out);
}

.nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background-color: currentColor;
  transform: scaleX(0);
  transform-origin: right;
  transition: transform var(--dur-base) var(--ease-out);
}

.nav__link:hover,
.nav__link.active {
  opacity: 1;
}

.nav__link.active::after {
  transform: scaleX(1);
  transform-origin: left;
}

@media (hover: hover) and (pointer: fine) {
  .nav__link:hover::after {
    transform: scaleX(1);
    transform-origin: left;
  }
}

.nav__item--cta {
  margin-left: var(--s-2);
}

/* Über dem Abendhimmel eine neutrale statt rote Handlungsfläche. */
.header:not(.scrolled) .nav__item--cta .btn--primary {
  --btn-bg: #F2EFE8;
  --btn-ink: #1B1D20;
  --btn-border: #F2EFE8;
  box-shadow: 0 6px 18px -8px rgba(0, 0, 0, 0.45);
}

/* Fortschritt als Fahrdraht unter dem Header */
.header__progress {
  position: absolute;
  inset: auto 0 -1px;
  height: 2px;
  pointer-events: none;
}

.header__progress-bar {
  display: block;
  height: 100%;
  background-color: var(--color-primary);
  transform: scaleX(var(--progress, 0));
  transform-origin: left;
}

/* Toggle */
.nav__toggle {
  display: none;
  position: relative;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  color: inherit;
}

.nav__toggle-line {
  position: absolute;
  left: 12px;
  right: 12px;
  height: 1.5px;
  background-color: currentColor;
  transition: transform var(--dur-base) var(--ease-out);
}

.nav__toggle-line:first-child {
  transform: translateY(-4px);
}

.nav__toggle-line:last-child {
  transform: translateY(4px);
}

.nav__toggle.active .nav__toggle-line:first-child {
  transform: rotate(45deg);
}

.nav__toggle.active .nav__toggle-line:last-child {
  transform: rotate(-45deg);
}

@media (max-width: 960px) {
  .nav__toggle {
    display: block;
    z-index: 2;
  }

  .nav__menu {
    position: fixed;
    inset: 0;
    z-index: 1;
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    gap: var(--s-2);
    padding: calc(var(--header-h) + var(--s-6)) var(--gutter) var(--s-8);
    background-color: var(--graphite-950);
    color: var(--ink-light);
    clip-path: inset(0 0 100% 0);
    visibility: hidden;
    transition: clip-path 520ms var(--ease-in-out), visibility 0s linear 520ms;
  }

  .nav__menu.active {
    clip-path: inset(0 0 0 0);
    visibility: visible;
    transition: clip-path 520ms var(--ease-in-out), visibility 0s;
  }

  .nav__link {
    font-family: var(--font-display);
    font-stretch: var(--display-stretch);
    font-size: clamp(2rem, 9vw, 3rem);
    font-weight: 600;
    line-height: 1.15;
    opacity: 1;
  }

  .nav__link::after {
    display: none;
  }

  .nav__item--cta {
    margin: var(--s-6) 0 0;
  }

  .header.menu-active {
    color: var(--ink-light);
  }

  .header.menu-active::before {
    opacity: 0;
  }
}

/* Native Scroll-driven Animation: läuft auf dem Compositor, ohne JS.
   Browser ohne Unterstützung nutzen den JS-Fallback in main.js. */
@supports (animation-timeline: scroll()) {
  .header__progress-bar {
    animation: progress-grow linear both;
    animation-timeline: scroll(root block);
  }

  @keyframes progress-grow {
    from { transform: scaleX(0); }
    to { transform: scaleX(1); }
  }
}