/* ── Site Header ────────────────────────────────────── */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--white);
  transition: background-color .25s ease, box-shadow .25s ease,
              border-color .25s ease, backdrop-filter .25s ease;
  border-bottom: 1px solid var(--neutral-200);
}
.site-header.is-scrolled {
  background: rgba(255, 255, 255, 0.72);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  backdrop-filter: saturate(180%) blur(20px);
  border-bottom-color: rgba(229, 231, 235, 0.6);
  box-shadow: 0 1px 0 rgba(229, 231, 235, 0.4),
              0 8px 24px rgba(13, 46, 68, 0.05);
}
@supports not ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
  .site-header.is-scrolled { background: rgba(255, 255, 255, 0.96); }
}

/* ── Hauptzeile ─────────────────────────────────────── */
.header-main .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-8);
  height: var(--header-height);
}

.header-logo img {
  height: 48px;
  width: auto;
  display: block;
}

/* ── Navigation ─────────────────────────────────────── */
.header-nav {
  display: flex;
  align-items: center;
  gap: var(--space-6);
}
.header-nav a {
  color: var(--neutral-700);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 10px 2px;
  position: relative;
  transition: color .2s ease;
}
.header-nav a::after {
  content: "";
  position: absolute;
  left: 50%;
  right: 50%;
  bottom: -2px;
  height: 1px;
  background: var(--primary-600);
  transition: left .25s ease, right .25s ease;
}
.header-nav a:hover { color: var(--primary-700); }
.header-nav a:hover::after,
.header-nav a.is-active::after { left: 0; right: 0; }
.header-nav a.is-active { color: var(--primary-700); }

/* ── Burger ─────────────────────────────────────────── */
.header-burger {
  display: none;
  width: 44px;
  height: 44px;
  border: 1px solid var(--neutral-300);
  background: var(--white);
  cursor: pointer;
  padding: 0;
  align-items: center;
  justify-content: center;
}
.header-burger span,
.header-burger span::before,
.header-burger span::after {
  display: block;
  width: 20px;
  height: 1.5px;
  background: var(--neutral-800);
  position: relative;
}
.header-burger span::before,
.header-burger span::after { content: ""; position: absolute; left: 0; }
.header-burger span::before { top: -6px; }
.header-burger span::after  { top:  6px; }

/* ── Responsive ─────────────────────────────────────── */
@media (max-width: 1024px) {
  .header-nav { gap: var(--space-5); }
  .header-nav a { font-size: 13px; letter-spacing: 0.05em; }
}

@media (max-width: 900px) {
  .header-burger { display: inline-flex; }
  .header-nav { display: none; }

  .header-nav.is-open {
    display: flex;
    position: absolute;
    top: var(--header-height);
    left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--white);
    border-top: 1px solid var(--neutral-200);
    border-bottom: 1px solid var(--neutral-200);
    box-shadow: 0 12px 24px rgba(13, 46, 68, 0.08);
    padding: var(--space-4) var(--container-pad);
    max-height: calc(100vh - var(--header-height));
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }
  .header-nav.is-open a {
    padding: 16px 0;
    border-bottom: 1px solid var(--neutral-100);
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 0.08em;
  }
  .header-nav.is-open a:last-child { border-bottom: none; }
  .header-nav.is-open a::after { display: none; }
}