/*
  MODERN COMPONENTS 2025
  ======================
  Header, Navigation, Buttons, Cards
*/

@layer components {
  
  /* ============================================
     MODERN HEADER SYSTEM
     ============================================ */
  
  .modern-header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--surface-primary);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--neutral-200);
    transition: all var(--duration-normal) var(--ease-out);
    
    /* Container Query Support */
    container-type: inline-size;
  }

  .modern-header.scrolled {
    background: color-mix(in srgb, var(--surface-primary) 90%, transparent);
    box-shadow: var(--shadow-lg);
  }

  .header-container {
    display: grid;
    grid-template-columns: auto 1fr auto;
    align-items: center;
    gap: var(--space-md);
    padding-block: var(--space-sm);
    max-inline-size: var(--container-7xl);
    margin-inline: auto;
    padding-inline: var(--space-md);
  }

  /* Logo Section */
  .header-logo {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    font-weight: 700;
    font-size: var(--font-size-xl);
    color: var(--brand-primary);
    text-decoration: none;
  }

  .header-logo img {
    block-size: clamp(2rem, 5vw, 3rem);
    inline-size: auto;
    border-radius: var(--radius-md);
  }

  /* ============================================
     MODERN NAVIGATION
     ============================================ */
  
  .main-nav {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-xs);
  }

  .nav-list {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    padding: 0;
    margin: 0;
    list-style: none;
  }

  .nav-item {
    position: relative;
  }

  .nav-link {
    display: flex;
    align-items: center;
    gap: var(--space-2xs);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-lg);
    font-weight: 500;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all var(--duration-fast) var(--ease-out);
    position: relative;
    overflow: hidden;
  }

  .nav-link::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--brand-primary);
    opacity: 0;
    transform: translateY(100%);
    transition: all var(--duration-normal) var(--ease-out);
    border-radius: inherit;
  }

  .nav-link:hover::before,
  .nav-link:focus-visible::before {
    opacity: 0.1;
    transform: translateY(0);
  }

  .nav-link:hover,
  .nav-link:focus-visible {
    color: var(--brand-primary);
    transform: translateY(-1px);
  }

  .nav-link.active {
    background: var(--brand-primary);
    color: white;
    box-shadow: var(--shadow-md);
  }

  .nav-icon {
    inline-size: 1.25rem;
    block-size: 1.25rem;
    fill: currentColor;
  }

  /* ============================================
     HEADER ACTIONS
     ============================================ */
  
  .header-actions {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
  }

  /* Modern Button System */
  .btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2xs);
    padding: var(--space-xs) var(--space-sm);
    border: none;
    border-radius: var(--radius-lg);
    font-family: inherit;
    font-size: var(--font-size-sm);
    font-weight: 500;
    line-height: 1;
    cursor: pointer;
    text-decoration: none;
    transition: all var(--duration-fast) var(--ease-out);
    position: relative;
    overflow: hidden;
    white-space: nowrap;
    
    /* Container Query for Responsive Buttons */
    container-type: inline-size;
  }

  .btn::before {
    content: '';
    position: absolute;
    inset: 0;
    background: currentColor;
    opacity: 0;
    transition: opacity var(--duration-fast) var(--ease-out);
  }

  .btn:hover::before {
    opacity: 0.1;
  }

  .btn:active {
    transform: translateY(1px);
    transition-duration: var(--duration-instant);
  }

  /* Button Variants */
  .btn--primary {
    background: var(--brand-primary);
    color: white;
    box-shadow: var(--shadow-sm);
  }

  .btn--primary:hover {
    background: color-mix(in srgb, var(--brand-primary) 90%, black);
    box-shadow: var(--shadow-md);
    transform: translateY(-1px);
  }

  .btn--secondary {
    background: var(--surface-secondary);
    color: var(--text-primary);
    border: 1px solid var(--neutral-300);
  }

  .btn--secondary:hover {
    background: var(--surface-tertiary);
    border-color: var(--brand-primary);
  }

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

  .btn--ghost:hover {
    background: var(--surface-secondary);
    color: var(--text-primary);
  }

  /* Icon Button */
  .btn--icon {
    padding: var(--space-xs);
    inline-size: 2.5rem;
    block-size: 2.5rem;
  }

  .btn--icon svg {
    inline-size: 1.25rem;
    block-size: 1.25rem;
    fill: currentColor;
  }

  /* ============================================
     THEME TOGGLE
     ============================================ */
  
  .theme-toggle {
    position: relative;
    inline-size: 3rem;
    block-size: 1.5rem;
    background: var(--neutral-300);
    border: none;
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: background-color var(--duration-normal) var(--ease-out);
  }

  .theme-toggle::before {
    content: '';
    position: absolute;
    top: 2px;
    left: 2px;
    inline-size: 1.25rem;
    block-size: 1.25rem;
    background: white;
    border-radius: var(--radius-full);
    transition: transform var(--duration-normal) var(--ease-out);
    box-shadow: var(--shadow-sm);
  }

  .theme-toggle[aria-pressed="true"] {
    background: var(--brand-primary);
  }

  .theme-toggle[aria-pressed="true"]::before {
    transform: translateX(1.5rem);
  }

  /* ============================================
     MOBILE MENU
     ============================================ */
  
  .mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    padding: var(--space-xs);
    background: none;
    border: none;
    cursor: pointer;
  }

  .hamburger-line {
    inline-size: 1.5rem;
    block-size: 2px;
    background: var(--text-primary);
    border-radius: var(--radius-sm);
    transition: all var(--duration-normal) var(--ease-out);
    transform-origin: center;
  }

  .mobile-menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
  }

  .mobile-menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(2) {
    opacity: 0;
  }

  .mobile-menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
  }

  .mobile-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--surface-primary);
    border-top: 1px solid var(--neutral-200);
    box-shadow: var(--shadow-lg);
    z-index: 999;
  }

  .mobile-nav.active {
    display: block;
    animation: slideDown var(--duration-normal) var(--ease-out);
  }

  .mobile-nav-list {
    padding: var(--space-md);
    list-style: none;
  }

  .mobile-nav-item {
    border-bottom: 1px solid var(--neutral-200);
  }

  .mobile-nav-item:last-child {
    border-bottom: none;
  }

  .mobile-nav-link {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) 0;
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--duration-fast) var(--ease-out);
  }

  .mobile-nav-link:hover {
    color: var(--brand-primary);
  }

  /* ============================================
     PROMOTIONAL BANNER
     ============================================ */
  
  .promo-banner {
    position: relative;
    background: linear-gradient(
      135deg, 
      var(--brand-primary), 
      var(--brand-secondary)
    );
    color: white;
    text-align: center;
    padding: var(--space-sm);
    overflow: hidden;
  }

  .promo-banner::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(
      90deg,
      transparent,
      rgba(255, 255, 255, 0.1),
      transparent
    );
    transform: translateX(-100%);
    animation: shine 3s infinite;
  }

  .promo-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    max-inline-size: var(--container-6xl);
    margin-inline: auto;
  }

  .promo-text {
    font-weight: 600;
    font-size: var(--font-size-sm);
  }

  .promo-close {
    position: absolute;
    top: var(--space-xs);
    right: var(--space-xs);
    background: rgba(255, 255, 255, 0.2);
    border: none;
    border-radius: var(--radius-full);
    padding: var(--space-2xs);
    color: white;
    cursor: pointer;
    transition: background-color var(--duration-fast) var(--ease-out);
  }

  .promo-close:hover {
    background: rgba(255, 255, 255, 0.3);
  }

  /* ============================================
     RESPONSIVE DESIGN
     ============================================ */
  
  @container (max-width: 768px) {
    .main-nav {
      display: none;
    }
    
    .mobile-menu-toggle {
      display: flex;
    }
    
    .header-actions > .btn:not(.btn--icon) {
      display: none;
    }
  }

  @container (max-width: 480px) {
    .header-container {
      gap: var(--space-sm);
    }
    
    .promo-text {
      font-size: var(--font-size-xs);
    }
    
    .promo-content {
      flex-direction: column;
      gap: var(--space-xs);
    }
  }

  /* ============================================
     ANIMATIONS
     ============================================ */
  
  @keyframes slideDown {
    from {
      opacity: 0;
      transform: translateY(-10px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }

  @keyframes shine {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
  }

  /* Focus Ring for Accessibility */
  .btn:focus-visible,
  .nav-link:focus-visible,
  .theme-toggle:focus-visible,
  .mobile-menu-toggle:focus-visible {
    outline: 2px solid var(--brand-primary);
    outline-offset: 2px;
  }
}