/* ========================================
   Header CSS - Single Source of Truth
   ======================================== */

/* Design Tokens (CSS Variables) */
:root {
  /* Colors */
  --color-primary: #005AA0;
  --color-primary-hover: #004680;
  --color-info: #4EA6DC;
  --color-success: #2FBDB6;
  --color-error: #DC2626;
  --color-border: #E5E7EB;
  --color-text: #111827;
  --color-text-secondary: #6B7280;
  --color-text-muted: #9CA3AF;
  --color-bg: #FFFFFF;
  --color-bg-secondary: #F9FAFB;
  --color-bg-tertiary: #F3F4F6;

  /* Spacing */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;

  /* Sizing */
  --header-height: 64px;
  --input-height: 44px;
  --button-height: 40px;
  --button-height-lg: 44px;
  --sidebar-width: 340px;
  --ai-flyout-w: 280px;

  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.08);

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;

  /* Font */
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Apple SD Gothic Neo", "Noto Sans KR", sans-serif;
}

/* ========================================
   Header Base Styles
   ======================================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  padding: 0 var(--spacing-xl);
}

.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  height: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 24px;
}

.site-logo {
  font-size: 20px;
  font-weight: 700;
  color: var(--color-primary);
  text-decoration: none;
}

.site-logo:hover {
  opacity: 0.9;
}

/* ========================================
   Horizontal Flyout Navigation
   ======================================== */
.nav-menu {
  display: flex;
  align-items: center;
  position: relative;
}

.nav-item {
  position: relative;
  display: flex;
  align-items: center;
}

.nav-item-ai {
  position: relative;
}

.nav-item-archive {
  position: relative;
  margin-left: 16px;
  padding-left: 16px;
}

/* Divider as pseudo-element (fixed to Archive) */
.nav-item-archive::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 1px;
  height: 18px;
  background: var(--color-border);
  border-radius: 1px;
}

/* Slot: expands to push Archive right */
.nav-slot {
  width: 0;
  overflow: hidden;
  flex: 0 0 auto;
  transition: width 150ms ease;
}

.nav-menu.ai-open .nav-slot {
  width: var(--ai-flyout-w);
}

/* Hide original divider element */
.nav-divider {
  display: none;
}

.nav-trigger {
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text);
  border-radius: var(--radius-lg);
  transition: background 120ms ease;
  white-space: nowrap;
}

.nav-trigger:hover,
.nav-trigger:focus {
  background: rgba(0, 90, 160, 0.08);
}

.nav-trigger[aria-expanded="true"],
.nav-trigger.active {
  color: var(--color-primary);
  font-weight: 600;
}

/* AI Flyout inside slot (not absolute) */
#ai-flyout {
  display: flex;
  align-items: center;
  height: 100%;
  opacity: 0;
  transition: opacity 150ms ease;
}

#ai-flyout.active {
  opacity: 1;
}

/* Archive Flyout (still absolute, right of archive trigger) */
.archive-h-flyout {
  position: absolute;
  top: 50%;
  left: 100%;
  transform: translateY(-50%) translateX(-10px);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 150ms ease, transform 150ms ease, visibility 150ms ease;
}

.archive-h-flyout.active {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateY(-50%) translateX(0);
}

.h-flyout-panel {
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: none;
  border-radius: var(--radius-lg);
  box-shadow: 0 8px 24px rgba(17, 24, 39, 0.08);
  padding: var(--spacing-sm);
  padding-right: calc(var(--spacing-sm) + 8px);
  display: flex;
  gap: 2px;
  white-space: nowrap;
}

.h-flyout-link {
  display: block;
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: 14px;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  transition: background 120ms ease, color 120ms ease;
  white-space: nowrap;
}

.h-flyout-link:hover,
.h-flyout-link:focus {
  background: rgba(0, 90, 160, 0.08);
  color: var(--color-primary);
}

/* Archive Horizontal Flyout with Dropdown */
.archive-h-flyout {
  padding-left: var(--spacing-sm);
}

.archive-h-panel {
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: none;
  border-radius: var(--radius-lg);
  box-shadow: 0 8px 24px rgba(17, 24, 39, 0.08);
  padding: var(--spacing-sm);
  display: flex;
  gap: 2px;
}

.archive-cat {
  position: relative;
}

.archive-cat-trigger {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background 120ms ease;
  white-space: nowrap;
}

.archive-cat-trigger:hover,
.archive-cat-trigger:focus {
  background: rgba(0, 90, 160, 0.08);
}

.archive-cat-trigger[aria-expanded="true"] {
  color: var(--color-primary);
  background: rgba(0, 90, 160, 0.08);
}

.archive-cat-trigger::after {
  content: '';
  width: 0;
  height: 0;
  border-left: 4px solid transparent;
  border-right: 4px solid transparent;
  border-top: 5px solid currentColor;
  opacity: 0.5;
  transition: transform 150ms ease;
}

.archive-cat-trigger[aria-expanded="true"]::after {
  transform: rotate(180deg);
}

/* Dropdown inside Archive */
.archive-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 200px;
  padding-top: 6px;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(-4px);
  transition: opacity 150ms ease, transform 150ms ease, visibility 150ms ease;
  z-index: 1002;
}

.archive-dropdown.active {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transform: translateY(0);
}

.archive-dropdown-panel {
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: none;
  border-radius: var(--radius-lg);
  box-shadow: 0 8px 24px rgba(17, 24, 39, 0.08);
  padding: var(--spacing-sm);
}

.archive-dropdown-link {
  display: block;
  padding: 8px var(--spacing-md);
  font-size: 13px;
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  transition: background 120ms ease, color 120ms ease;
  white-space: nowrap;
}

.archive-dropdown-link:hover,
.archive-dropdown-link:focus {
  background: rgba(0, 90, 160, 0.08);
  color: var(--color-primary);
}

/* ========================================
   Header Right Section
   ======================================== */
.header-right {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  position: relative;
  z-index: 100;
}

/* Credit Badge */
.credit-badge {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background: linear-gradient(135deg, #fde047 0%, #facc15 100%);
  color: #713f12;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
  transition: transform 0.15s, box-shadow 0.15s;
}

.credit-badge:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(250, 204, 21, 0.4);
}

.credit-badge svg {
  flex-shrink: 0;
}

/* User Dropdown */
.user-menu {
  position: relative;
  display: flex;
  align-items: center;
  gap: 0;
}

/* UI-013: Logged-in user button - subtle brand tint (matches login button) */
.header-user-btn {
  background: rgba(11, 91, 211, 0.08);
  border: 1px solid rgba(11, 91, 211, 0.18);
  color: var(--color-primary, #0b5bd3);
  height: 36px;
  padding: 0 12px 0 8px;
  border-radius: 12px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
  cursor: pointer;
  outline: none;
  -webkit-tap-highlight-color: transparent;
  transition: background 120ms ease, border-color 120ms ease;
}

.header-user-btn:hover {
  background: rgba(11, 91, 211, 0.14);
  border-color: rgba(11, 91, 211, 0.24);
}

.header-user-btn:focus-visible {
  outline: 0;
  box-shadow: 0 0 0 3px rgba(11, 91, 211, 0.18);
}

/* UI-013: Avatar hidden, show username only */
.header-user-avatar {
  display: none !important;
}

.header-user-id {
  display: inline-block;
  max-width: 120px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-size: 14px;
  line-height: 1;
}

/* Admin mode active indicator - yellow highlight */
.header-user-id.admin-mode-active {
  color: #f59e0b;
  font-weight: 600;
  padding: 2px 8px;
  background: rgba(245, 158, 11, 0.15);
  border-radius: 4px;
}

/* Pending user notification badge */
.pending-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 20px;
  height: 20px;
  padding: 0 6px;
  margin-left: 8px;
  background: #DC2626;
  color: white;
  font-size: 11px;
  font-weight: 600;
  border-radius: 10px;
  line-height: 1;
  text-decoration: none;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.15s ease;
}

.pending-badge:hover {
  background: #B91C1C;
  transform: scale(1.1);
}

.pending-badge:active {
  transform: scale(0.95);
}

/* Legacy: keep for backward compatibility */
.user-avatar {
  width: 36px;
  height: 36px;
  border: none;
  border-radius: 50%;
  background: var(--color-primary);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  outline: none;
  -webkit-tap-highlight-color: transparent;
}

.user-dropdown {
  position: absolute;
  top: 100%;
  right: 0;
  margin-top: var(--spacing-sm);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  min-width: 200px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: var(--transition-normal);
  pointer-events: none;
  z-index: 1001;
}

.user-menu.active .user-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  pointer-events: auto;
}

.user-dropdown a {
  display: block;
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: 14px;
  color: var(--color-text);
}

.user-dropdown a:hover {
  background: var(--color-bg-tertiary);
}

/* Admin Mode Toggle Button (v1.9.2) */
.admin-mode-btn {
  display: block;
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: 14px;
  color: var(--color-text);
  background: none;
  border: none;
  text-align: left;
  cursor: pointer;
  transition: background 120ms ease;
}

.admin-mode-btn:hover {
  background: var(--color-bg-tertiary);
}

.admin-mode-btn.admin-mode-on {
  color: #f59e0b;
  font-weight: 500;
}

/* ========================================
   Mobile Menu Toggle
   ======================================== */
.mobile-menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  color: var(--color-text);
  background: var(--color-bg);
  border: 1px solid rgba(0, 0, 0, 0.08);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background 120ms ease;
  flex-shrink: 0;
}

.mobile-menu-toggle:hover,
.mobile-menu-toggle:focus {
  background: rgba(0, 90, 160, 0.08);
}

.mobile-menu-toggle:focus {
  outline: 2px solid rgba(0, 0, 0, 0.25);
  outline-offset: 2px;
}

/* ========================================
   Mobile Menu Overlay
   ======================================== */
.mobile-menu-overlay {
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-bg);
  z-index: 999;
  padding: var(--spacing-lg);
  overflow-y: auto;
  transform: translateX(-100%);
  transition: transform 0.3s ease;
}

.mobile-menu-overlay.active {
  transform: translateX(0);
}

/* Mobile Accordion */
.mobile-accordion {
  border-bottom: 1px solid var(--color-border);
}

.mobile-accordion-trigger {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-md) 0;
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
  background: none;
  border: none;
  cursor: pointer;
}

.mobile-accordion-trigger .accordion-arrow {
  transition: transform 0.2s ease;
}

.mobile-accordion-trigger[aria-expanded="true"] .accordion-arrow {
  transform: rotate(180deg);
}

.mobile-accordion-content {
  display: none;
  padding-bottom: var(--spacing-md);
}

.mobile-accordion-content.active {
  display: block;
}

.mobile-accordion-content a {
  display: block;
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: 14px;
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
}

.mobile-accordion-content a:hover {
  background: var(--color-bg-tertiary);
  color: var(--color-primary);
}

/* Mobile Sub-accordion */
.mobile-sub-accordion {
  margin-left: var(--spacing-md);
}

.mobile-sub-trigger {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) 0;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text-secondary);
  background: none;
  border: none;
  cursor: pointer;
}

.mobile-sub-trigger .accordion-arrow {
  transition: transform 0.2s ease;
}

.mobile-sub-trigger[aria-expanded="true"] .accordion-arrow {
  transform: rotate(180deg);
}

.mobile-sub-content {
  display: none;
  padding-left: var(--spacing-md);
}

.mobile-sub-content.active {
  display: block;
}

.mobile-sub-content a {
  display: block;
  padding: var(--spacing-xs) var(--spacing-sm);
  font-size: 13px;
  color: var(--color-text-muted);
}

.mobile-sub-content a:hover {
  color: var(--color-primary);
}

/* ========================================
   Responsive Breakpoints
   ======================================== */

/* Tablet layout (768-1023px) */
@media (min-width: 768px) and (max-width: 1023px) {
  .mobile-menu-toggle {
    display: none;
  }

  .nav-trigger {
    padding: var(--spacing-sm) var(--spacing-md);
  }
}

/* Touch devices (pointer: coarse) */
@media (pointer: coarse) {
  .nav-trigger {
    min-height: 44px;
    padding: var(--spacing-sm) var(--spacing-lg);
  }

  .h-flyout-link,
  .archive-cat-trigger,
  .archive-dropdown-link {
    min-height: 44px;
    display: flex;
    align-items: center;
  }
}

/* Mobile (<768px) */
@media (max-width: 767px) {
  .nav-menu {
    display: none;
  }

  .mobile-menu-toggle {
    display: inline-flex;
  }

  .header-left {
    gap: 12px;
  }

  .site-header {
    padding: 0 var(--spacing-md);
  }

  .h-flyout,
  .archive-h-flyout {
    display: none !important;
  }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  .h-flyout,
  .archive-dropdown,
  .nav-item-archive,
  .mobile-menu-overlay {
    transition-duration: 0.01ms !important;
  }
}

/* ========================================
   Utility Classes
   ======================================== */
.hidden {
  display: none !important;
}

/* Button base styles (used in header) */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: var(--button-height);
  padding: 0 var(--spacing-lg);
  font-size: 14px;
  font-weight: 500;
  border-radius: var(--radius-sm);
  transition: var(--transition-fast);
  text-decoration: none;
  border: none;
  cursor: pointer;
}

.btn-primary {
  background: var(--color-primary);
  color: white;
}

.btn-primary:hover {
  background: var(--color-primary-hover);
}

/* UI-012: Desktop header login button - subtle brand tint */
#login-btn.header-login-btn {
  background: rgba(11, 91, 211, 0.08);
  border: 1px solid rgba(11, 91, 211, 0.18);
  color: var(--color-primary, #0b5bd3);
  height: 36px;
  padding: 0 14px;
  border-radius: 12px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  white-space: nowrap;
}

#login-btn.header-login-btn:hover {
  background: rgba(11, 91, 211, 0.14);
  border-color: rgba(11, 91, 211, 0.24);
}

#login-btn.header-login-btn:active {
  transform: translateY(1px);
}

#login-btn.header-login-btn:focus-visible {
  outline: 0;
  box-shadow: 0 0 0 3px rgba(11, 91, 211, 0.18);
}

.btn-ghost {
  color: var(--color-text-secondary);
}

.btn-ghost:hover {
  background: var(--color-bg-tertiary);
  color: var(--color-text);
}