/* Navigation Bar Styles */

/* Navbar Container - Static Positioning */
.navbar {
  position: relative;
  top: 0;
  left: 0;
  width: 100%;
  background-color: rgba(255, 255, 255, 0.5);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: var(--shadow-md);
  z-index: var(--z-fixed);
  transition: background-color var(--transition-base);
}

.navbar-container {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
  height: var(--header-height);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-lg);
}

/* Logo Area (Requirement 1.6) */
.navbar-logo {
  flex-shrink: 0;
  z-index: calc(var(--z-fixed) + 2);
}

.navbar-logo a {
  display: block;
  line-height: 0;
}

.navbar-logo img {
  height: 40px;
  width: auto;
  display: block;
}

/* Hamburger Menu Button - Hidden on Desktop (Requirement 1.3) */
.navbar-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-around;
  width: 30px;
  height: 24px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 12px;
  z-index: calc(var(--z-fixed) + 2);
  transition: transform var(--transition-base);
  /* Minimum touch target size for mobile (Requirement 8.5) */
  min-width: 48px;
  min-height: 48px;
}

.navbar-toggle:hover {
  transform: scale(1.1);
}

.navbar-toggle:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 4px;
}

.hamburger-line {
  width: 100%;
  height: 3px;
  background-color: var(--text-primary);
  border-radius: var(--radius-sm);
  transition: all var(--transition-base);
  transform-origin: center;
}

/* Hamburger Animation when Active */
.navbar-toggle.active .hamburger-line:nth-child(1) {
  transform: translateY(10.5px) rotate(45deg);
}

.navbar-toggle.active .hamburger-line:nth-child(2) {
  opacity: 0;
  transform: translateX(-20px);
}

.navbar-toggle.active .hamburger-line:nth-child(3) {
  transform: translateY(-10.5px) rotate(-45deg);
}

/* Desktop Navigation Menu - Horizontal Layout (Requirement 1.2) */
.navbar-menu {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: var(--spacing-xl);
  align-items: center;
  flex: 1;
}

/* Navbar Actions - Right Side */
.navbar-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
  margin-left: auto;
}

.navbar-search-link {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-sm) var(--spacing-md);
  background-color: transparent;
  color: var(--text-primary);
  text-decoration: none;
  border-radius: var(--radius-sm);
  font-weight: var(--font-weight-medium);
  transition: all var(--transition-base);
  border: 1px solid var(--border-light);
}

.navbar-search-link:hover {
  color: var(--primary-color);
  background-color: var(--bg-secondary);
  border-color: var(--primary-color);
}

.navbar-search-link:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

.search-text {
  font-size: var(--font-size-sm);
}

.search-icon {
  font-size: var(--font-size-base);
  opacity: 0.7;
}

.search-action {
  font-size: var(--font-size-sm);
  opacity: 0.8;
}

/* Language Switcher */
.language-switcher {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-xs) var(--spacing-md);
  background-color: var(--bg-secondary);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-light);
}

.lang-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-sm);
  transition: all var(--transition-base);
  min-width: 40px;
}

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

.lang-btn:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

.lang-btn.active {
  color: var(--primary-color);
  font-weight: var(--font-weight-semibold);
  background-color: var(--bg-primary);
}

.lang-divider {
  color: var(--border-light);
  font-size: var(--font-size-sm);
  user-select: none;
}

.navbar-menu li {
  margin: 0;
}

.navbar-menu a {
  display: block;
  color: var(--text-primary);
  text-decoration: none;
  font-size: var(--font-size-base);
  font-weight: var(--font-weight-medium);
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-sm);
  transition: all var(--transition-base);
  position: relative;
}

.navbar-menu a:hover {
  color: var(--primary-color);
  background-color: var(--bg-secondary);
}

.navbar-menu a:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
}

/* Active link indicator - only change text color, no background */
.navbar-menu a.active {
  color: var(--primary-color);
}

/* Remove the underline indicator */

/* Tablet Breakpoint (768px - 1023px) */
@media (min-width: 768px) and (max-width: 1023px) {
  .navbar-container {
    padding: 0 var(--spacing-md);
  }
  
  .navbar-menu {
    gap: var(--spacing-lg);
  }
  
  .navbar-menu a {
    font-size: var(--font-size-sm);
    padding: var(--spacing-xs) var(--spacing-sm);
  }
}

/* Mobile Breakpoint - Hamburger Menu (Requirement 1.3, 768px断点) */
@media (max-width: 767px) {
  .navbar-container {
    height: var(--header-height-mobile);
    padding: 0 var(--spacing-md);
  }
  
  .navbar-logo img {
    height: 32px;
  }
  
  /* Show Hamburger Button on Mobile */
  .navbar-toggle {
    display: flex;
  }
  
  /* Mobile Menu - Vertical Layout */
  .navbar-menu {
    position: fixed;
    top: var(--header-height-mobile);
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    background-color: var(--bg-primary);
    box-shadow: var(--shadow-lg);
    padding: var(--spacing-md) 0;
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height var(--transition-slow), 
                opacity var(--transition-base);
    z-index: calc(var(--z-fixed) + 1);
    flex: none;
  }
  
  /* Mobile Actions */
  .navbar-actions {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    padding: var(--spacing-md);
    background-color: var(--bg-primary);
    box-shadow: var(--shadow-lg);
    z-index: calc(var(--z-fixed) + 2);
    display: none;
    flex-direction: column;
    gap: var(--spacing-md);
  }
  
  .navbar-menu.active ~ .navbar-actions {
    display: flex;
  }
  
  .navbar-search-link {
    width: 100%;
    justify-content: center;
    padding: var(--spacing-md);
    min-height: 48px;
  }
  
  .language-switcher {
    width: 100%;
    justify-content: center;
    padding: var(--spacing-sm) var(--spacing-md);
  }
  
  .lang-btn {
    min-width: 60px;
    min-height: 40px;
  }
  
  /* Mobile Menu Open State */
  .navbar-menu.active {
    max-height: calc(100vh - var(--header-height-mobile));
    opacity: 1;
    overflow-y: auto;
  }
  
  .navbar-menu li {
    width: 100%;
    border-bottom: 1px solid var(--border-light);
  }
  
  .navbar-menu li:last-child {
    border-bottom: none;
  }
  
  .navbar-menu a {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: var(--font-size-base);
    border-radius: 0;
    /* Minimum touch target size for mobile (Requirement 8.5) */
    min-height: 48px;
    min-width: 48px;
    display: flex;
    align-items: center;
  }
  
  .navbar-menu a:hover,
  .navbar-menu a:focus {
    background-color: var(--bg-secondary);
  }
  
  
  .navbar-menu a.active {
    color: var(--primary-color);
  }
  
  /* Slide-in animation for menu items */
  .navbar-menu.active li {
    animation: slideInFromLeft 0.3s ease forwards;
  }
  
  .navbar-menu.active li:nth-child(1) { animation-delay: 0.05s; }
  .navbar-menu.active li:nth-child(2) { animation-delay: 0.1s; }
  .navbar-menu.active li:nth-child(3) { animation-delay: 0.15s; }
  .navbar-menu.active li:nth-child(4) { animation-delay: 0.2s; }
  .navbar-menu.active li:nth-child(5) { animation-delay: 0.25s; }
  .navbar-menu.active li:nth-child(6) { animation-delay: 0.3s; }
}

/* Slide-in animation keyframes */
@keyframes slideInFromLeft {
  from {
    opacity: 0;
    transform: translateX(-20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* Prevent body scroll when mobile menu is open */
body.menu-open {
  overflow: hidden;
}

/* Navbar scroll behavior - optional enhancement */
.navbar.scrolled {
  background-color: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(10px);
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  .navbar {
    border-bottom: 2px solid var(--text-primary);
  }
  
  .navbar-menu a:focus,
  .navbar-toggle:focus {
    outline-width: 3px;
  }
}

/* Keyboard focus styles for accessibility */
.navbar-menu a:focus-visible,
.navbar-toggle:focus-visible {
  outline: 3px solid var(--primary-color);
  outline-offset: 2px;
}

/* Skip to main content link for keyboard users */
.skip-to-main {
  position: absolute;
  top: -100px;
  left: 0;
  background: var(--primary-color);
  color: var(--text-white);
  padding: var(--spacing-sm) var(--spacing-md);
  text-decoration: none;
  z-index: calc(var(--z-fixed) + 10);
}

.skip-to-main:focus {
  top: 0;
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
  .navbar,
  .navbar-menu,
  .navbar-toggle,
  .hamburger-line,
  .navbar-menu a {
    transition: none;
  }
  
  .navbar-menu.active li {
    animation: none;
  }
}