/* ============================================================
   header.css — 모든 메인 페이지 공통 헤더 + 사이트맵 + 테마 토글
   landing.css 의 :root 토큰을 그대로 사용한다.
   ============================================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  border-bottom: 1px solid var(--border);
  background: color-mix(in oklch, var(--bg-page) 82%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

.site-header-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0.7rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

/* ---- brand ---- */
.site-brand {
  font-weight: 800;
  font-size: 1.05rem;
  letter-spacing: -0.02em;
  color: var(--text);
  text-decoration: none;
  display: inline-flex;
  align-items: baseline;
  gap: 0.1rem;
}

.site-brand .brand-mark {
  font-family: var(--font-mono);
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--accent);
}

/* ---- right actions group ---- */
.site-header-actions {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

/* ---- nav (sitemap) ---- */
.site-nav {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.site-nav a {
  display: inline-flex;
  align-items: center;
  padding: 0.45rem 0.8rem;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-muted);
  text-decoration: none;
  border-radius: var(--radius);
  transition: color 0.18s, background 0.18s;
}

.site-nav a:hover {
  color: var(--text);
  background: var(--bg-elev);
}

.site-nav a[aria-current="page"] {
  color: var(--accent);
  background: var(--accent-dim);
}

/* ---- icon buttons (theme toggle, mobile menu) ---- */
.theme-toggle,
.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.3rem;
  height: 2.3rem;
  padding: 0;
  background: var(--bg-elev);
  color: var(--text-muted);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius);
  cursor: pointer;
  transition: color 0.18s, border-color 0.18s, background 0.18s, transform 0.18s;
}

.theme-toggle:hover,
.nav-toggle:hover {
  color: var(--accent);
  border-color: var(--accent-line);
  transform: translateY(-1px);
}

.theme-toggle .icon,
.nav-toggle .icon {
  width: 1.15rem;
  height: 1.15rem;
}

/* mobile menu button hidden on desktop */
.nav-toggle {
  display: none;
}

/* ============================================================
   RESPONSIVE — 모바일에서 nav 를 드롭다운 패널로
   ============================================================ */
@media (max-width: 720px) {
  .nav-toggle {
    display: inline-flex;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    right: 1rem;
    left: 1rem;
    flex-direction: column;
    align-items: stretch;
    gap: 0.15rem;
    padding: 0.5rem;
    background: var(--bg-elev);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    transform: translateY(-8px);
    pointer-events: none;
    transition: opacity 0.2s, transform 0.2s;
  }

  .site-nav.is-open {
    opacity: 1;
    transform: translateY(0.4rem);
    pointer-events: auto;
  }

  .site-nav a {
    padding: 0.65rem 0.9rem;
    font-size: 0.95rem;
  }
}