/* ==========================================================================
   Site header — sticky, blurred, config-driven nav (EN/CS)
   ========================================================================== */

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0);
  white-space: nowrap; border: 0;
}

.site-header {
  position: sticky; top: 0; z-index: 50;
  background: var(--header-bg);
  backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.site-header__inner {
  display: flex; align-items: center; gap: 24px;
  min-height: 88px;
}
.logo { display: inline-flex; align-items: center; flex: none; }
.logo__svg, .logo__img { height: 56px; width: auto; }
.logo__text { font-weight: 800; font-size: 18px; letter-spacing: -.01em; color: var(--heading); }

.main-nav {
  display: flex; align-items: center; gap: 28px;
  margin-left: auto;
}
.main-nav > a {
  font-size: 15px; font-weight: 600; color: var(--text-mute);
  white-space: nowrap; transition: color .15s ease;
}
.main-nav > a:hover { color: var(--text); }
.main-nav > a.is-active { color: var(--red); }

.site-header__actions { display: flex; align-items: center; gap: 12px; }

.lang-switch { display: inline-flex; align-items: center; gap: 2px; }
.lang-pill {
  display: inline-flex; align-items: center; justify-content: center;
  min-width: 34px; height: 32px; padding: 0 8px;
  font-size: 13px; font-weight: 700; color: var(--text-mute);
  border-radius: 7px; transition: background .15s ease, color .15s ease;
}
.lang-pill:hover { background: var(--surface-soft); color: var(--text); }
.lang-pill.is-active { color: var(--red); background: var(--red-soft); }

.header-cta { flex: none; }

/* Hamburger — hidden on desktop */
.nav-toggle {
  display: none;
  width: 42px; height: 42px;
  flex-direction: column; align-items: center; justify-content: center; gap: 5px;
  border-radius: 8px;
}
.nav-toggle span {
  display: block; width: 22px; height: 2px; background: var(--text);
  border-radius: 2px; transition: transform .2s ease, opacity .2s ease;
}
.nav-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

@media (max-width: 900px) {
  .nav-toggle { display: inline-flex; order: 3; }
  .header-cta { display: none; }
  .site-header__inner { min-height: 64px; }
  .site-header__actions { margin-left: auto; }
  .logo__svg, .logo__img { height: 34px; }
  .main-nav {
    position: absolute; left: 0; right: 0; top: 100%;
    flex-direction: column; align-items: stretch; gap: 0;
    background: var(--surface); border-bottom: 1px solid var(--border);
    padding: 8px 0; margin: 0;
    box-shadow: var(--shadow-md);
    max-height: 0; overflow: hidden; visibility: hidden;
    transition: max-height .25s ease, visibility .25s ease;
  }
  .main-nav.is-open { max-height: 80vh; visibility: visible; overflow: auto; }
  .main-nav > a { padding: 14px 40px; font-size: 16px; }
  .main-nav > a:not(:last-child) { border-bottom: 1px solid var(--border-soft); }
}