/* ============================================================
 * Header Section
 * 책임: Codex
 * Figma 노드 ID: [채워주세요]
 * 작업 명세: docs/HANDOFF.md → H-001 · Header
 * ============================================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  border-bottom: calc(var(--space-1) / 4) solid var(--color-border);
  background-color: var(--color-bg);
  transition: box-shadow var(--duration-fast) var(--ease-out);
}

.site-header--scrolled {
  box-shadow: var(--shadow-sm);
}

.site-header__inner {
  display: flex;
  align-items: center;
  min-block-size: var(--space-16);
  gap: var(--space-4);
}

.site-header__logo-link {
  display: inline-flex;
  align-items: center;
  flex-shrink: 0;
  gap: var(--space-2);
  border-radius: var(--radius-md);
  color: var(--color-text);
  transition: color var(--duration-fast) var(--ease-out);
}

.site-header__logo-link:hover {
  color: var(--color-brand-500);
}

.site-header__logo-link:focus-visible {
  outline: calc(var(--space-1) / 2) solid var(--color-brand-500);
  outline-offset: calc(var(--space-1) / 2);
}

.site-header__logo-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 calc(var(--space-8) + var(--space-1));
  inline-size: calc(var(--space-8) + var(--space-1));
  block-size: calc(var(--space-8) + var(--space-1));
  border-radius: var(--radius-md);
  background-color: var(--color-brand-500);
  color: var(--color-text-on-brand);
}

.site-header__logo-text {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-bold);
  line-height: var(--line-height-tight);
}

.site-header__nav {
  display: none;
}

.site-header__nav-link {
  color: var(--color-text-sub);
  font-size: var(--font-size-md);
  font-weight: var(--font-weight-medium);
  transition: color var(--duration-fast) var(--ease-out);
}

.site-header__nav-link:hover {
  color: var(--color-brand-500);
}

.site-header__nav-link:focus-visible {
  outline: calc(var(--space-1) / 2) solid var(--color-brand-500);
  outline-offset: calc(var(--space-1) / 2);
  border-radius: var(--radius-sm);
  color: var(--color-brand-500);
}

.site-header__actions {
  display: none;
}

.site-header__menu-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  inline-size: calc(var(--space-10) + var(--space-1));
  block-size: calc(var(--space-10) + var(--space-1));
  margin-inline-start: auto;
  border-radius: var(--radius-md);
  color: var(--color-text);
  transition:
    background-color var(--duration-fast) var(--ease-out),
    color var(--duration-fast) var(--ease-out);
}

.site-header__menu-toggle:hover {
  background-color: var(--color-bg-muted);
  color: var(--color-brand-500);
}

.site-header__menu-toggle:focus-visible {
  outline: calc(var(--space-1) / 2) solid var(--color-brand-500);
  outline-offset: calc(var(--space-1) / 2);
}

.site-header__menu-icon {
  flex-shrink: 0;
}

.site-header__mobile-menu {
  position: absolute;
  inset-block-start: 100%;
  inset-inline: 0;
  z-index: var(--z-dropdown);
  padding: var(--space-4) var(--container-pad) var(--space-5);
  border-bottom: calc(var(--space-1) / 4) solid var(--color-border);
  background-color: var(--color-bg);
  box-shadow: var(--shadow-md);
  animation: site-header-mobile-menu var(--duration-normal) var(--ease-out);
}

.site-header__mobile-nav {
  display: grid;
  gap: var(--space-2);
  margin-block-end: var(--space-4);
}

.site-header__mobile-link {
  display: flex;
  align-items: center;
  min-block-size: calc(var(--space-10) + var(--space-1));
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  color: var(--color-text-sub);
  font-size: var(--font-size-md);
  font-weight: var(--font-weight-medium);
  transition:
    background-color var(--duration-fast) var(--ease-out),
    color var(--duration-fast) var(--ease-out);
}

.site-header__mobile-link:hover {
  background-color: var(--color-bg-muted);
  color: var(--color-brand-500);
}

.site-header__mobile-link:focus-visible {
  outline: calc(var(--space-1) / 2) solid var(--color-brand-500);
  outline-offset: calc(var(--space-1) / 2);
  color: var(--color-brand-500);
}

.site-header__mobile-actions {
  display: grid;
  gap: var(--space-2);
}

.site-header__mobile-button {
  inline-size: 100%;
}

@keyframes site-header-mobile-menu {
  from {
    opacity: 0;
    transform: translateY(calc(var(--space-2) * -1));
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (min-width: 768px) {
  .site-header__nav {
    display: flex;
    align-items: center;
    gap: var(--space-6);
    margin-inline-start: var(--space-8);
  }

  .site-header__actions {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    margin-inline-start: auto;
  }

  .site-header__menu-toggle {
    display: none;
  }

  .site-header__mobile-menu {
    display: none;
  }
}

@media (min-width: 1024px) {
  .site-header__inner {
    min-block-size: calc(var(--space-16) + var(--space-2));
    gap: var(--space-6);
  }

  .site-header__nav {
    gap: var(--space-8);
  }
}