/* Header Styles */
    header {
      background-color: white;
      box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
      position: fixed;
      width: 100%;
      top: 0;
      left: 0;
      z-index: 1000;
      backdrop-filter: blur(10px);
      -webkit-backdrop-filter: blur(10px);
      border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    }

    header .container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 18px 24px;
      max-width: 1400px;
      margin: 0 auto;
      min-height: 70px;
    }

    .logo {
      display: flex;
      align-items: center;
      flex-shrink: 0;
      transition: transform 0.2s ease;
    }

    .logo:hover {
      transform: translateY(-1px);
    }

    .logo a {
      display: flex;
      align-items: center;
      color: var(--dark-color, #333);
      font-weight: 700;
      font-size: 1.6rem;
      text-decoration: none;
      letter-spacing: -0.5px;
    }

    .logo img {
      height: 44px;
      margin-right: 12px;
      max-width: 100%;
      filter: drop-shadow(0 1px 2px rgba(0, 0, 0, 0.1));
      transition: filter 0.2s ease;
    }

    .logo:hover img {
      filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.15));
    }

    nav {
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    }

    nav ul {
      display: flex;
      gap: 1px;
      list-style: none;
      margin: 0;
      padding: 0;
      align-items: center;
    }

    nav li {
      position: relative;
    }

    nav a {
      color: var(--text-color, #333);
      font-weight: 600;
      padding: 12px 16px;
      position: relative;
      text-decoration: none;
      white-space: nowrap;
      font-size: 0.95rem;
      letter-spacing: 0.025em;
      border-radius: 8px;
      transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
      background: transparent;
    }

    nav a:hover {
      color: var(--primary-color, #4CAF50);
      background: rgba(76, 175, 80, 0.05);
      transform: translateY(-1px);
    }

    nav a::after {
      content: '';
      position: absolute;
      bottom: 8px;
      left: 50%;
      transform: translateX(-50%);
      width: 0;
      height: 2px;
      background: var(--primary-color, #4CAF50);
      transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
      border-radius: 1px;
    }

    nav a:hover::after,
    nav a.active::after {
      width: 60%;
    }

    nav a.active {
      color: var(--primary-color, #4CAF50);
      font-weight: 700;
    }

    .mobile-menu-toggle {
      display: none;
      flex-direction: column;
      gap: 5px;
      cursor: pointer;
      padding: 8px;
      background: none;
      border: none;
      z-index: 1001;
      border-radius: 6px;
      transition: all 0.2s ease;
      position: relative;
      overflow: hidden;
    }

    .mobile-menu-toggle:hover {
      background: rgba(0, 0, 0, 0.05);
    }

    .mobile-menu-toggle:active {
      transform: scale(0.95);
    }

    .mobile-menu-toggle span {
      width: 26px;
      height: 3px;
      background-color: var(--text-color, #333);
      transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
      border-radius: 2px;
      transform-origin: center;
    }

    .mobile-menu-toggle.active span:nth-child(1) {
      transform: rotate(45deg) translate(8px, 8px);
    }

    .mobile-menu-toggle.active span:nth-child(2) {
      opacity: 0;
      transform: translateX(20px);
    }

    .mobile-menu-toggle.active span:nth-child(3) {
      transform: rotate(-45deg) translate(8px, -8px);
    }

    /* Add space for fixed header */
    main {
      padding-top: 86px;
    }

    /* Tablet styles */
    @media (max-width: 1200px) {
      header .container {
        padding: 16px 20px;
        max-width: 100%;
      }
      
      nav ul {
        gap: 28px;
      }
      
      .logo img {
        height: 40px;
      }
      
      .logo a {
        font-size: 1.5rem;
      }
    }

    @media (max-width: 1024px) {
      header .container {
        padding: 14px 18px;
      }
      
      nav ul {
        gap: 24px;
      }
      
      nav a {
        padding: 10px 14px;
        font-size: 0.9rem;
      }
      
      .logo img {
        height: 38px;
      }
      
      .logo a {
        font-size: 1.4rem;
      }
    }

    /* Small tablet and large mobile */
    @media (max-width: 900px) {
      nav ul {
        gap: 20px;
      }
      
      nav a {
        font-size: 0.85rem;
        padding: 8px 12px;
      }
    }

    /* Mobile styles */
    @media (max-width: 768px) {
      header .container {
        padding: 12px 16px;
        min-height: 64px;
      }
      
      nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background: white;
        box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
        border-top: 1px solid rgba(0, 0, 0, 0.08);
        z-index: 999;
      }
      
      nav.active {
        display: block;
        animation: slideDown 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
      }
      
      nav ul {
        flex-direction: column;
        gap: 2px;
        padding: 8px;
        background: white;
      }
      
      nav li {
        width: 100%;
      }
      
      nav a {
        display: flex;
        align-items: center;
        padding: 14px 20px;
        margin: 0;
        border-radius: 8px;
        font-size: 1rem;
        font-weight: 600;
        transition: all 0.2s ease;
        border: none;
        background: transparent;
        position: relative;
        width: 100%;
        box-sizing: border-box;
      }

      nav a::after {
        display: none;
      }

      nav a::before {
        content: '';
        position: absolute;
        left: 20px;
        top: 50%;
        transform: translateY(-50%);
        width: 4px;
        height: 0;
        background: var(--primary-color, #4CAF50);
        border-radius: 2px;
        transition: height 0.2s ease;
      }
      
      nav a:hover {
        background: rgba(76, 175, 80, 0.06);
        color: var(--primary-color, #4CAF50);
        padding-left: 32px;
      }

      nav a:hover::before {
        height: 20px;
      }

      nav a.active {
        background: rgba(76, 175, 80, 0.1);
        color: var(--primary-color, #4CAF50);
        font-weight: 700;
        padding-left: 32px;
      }

      nav a.active::before {
        height: 20px;
      }
      
      .mobile-menu-toggle {
        display: flex;
      }
      
      .logo img {
        height: 36px;
      }
      
      .logo a {
        font-size: 1.3rem;
      }
      
      main {
        padding-top: 76px;
      }
    }

    /* Small mobile devices */
    @media (max-width: 480px) {
      header .container {
        padding: 10px 14px;
        min-height: 60px;
      }
      
      .logo img {
        height: 32px;
        margin-right: 10px;
      }
      
      .logo a {
        font-size: 1.2rem;
      }
      
      nav a {
        padding: 14px 20px;
        font-size: 0.95rem;
        margin: 0 12px;
      }
      
      main {
        padding-top: 70px;
      }
      
      .mobile-menu-toggle span {
        width: 24px;
        height: 2.5px;
      }
    }

    /* Very small screens */
    @media (max-width: 360px) {
      header .container {
        padding: 8px 12px;
        min-height: 56px;
      }
      
      .logo img {
        height: 28px;
        margin-right: 8px;
      }
      
      .logo a {
        font-size: 1.1rem;
      }
      
      nav a {
        padding: 12px 16px;
        font-size: 0.9rem;
        margin: 0 8px;
      }
      
      main {
        padding-top: 64px;
      }
    }

    /* Animation for mobile menu */
    @keyframes slideDown {
      from {
        opacity: 0;
        transform: translateY(-20px);
      }
      to {
        opacity: 1;
        transform: translateY(0);
      }
    }

    /* High DPI displays */
    @media (-webkit-min-device-pixel-ratio: 2), (min-resolution: 192dpi) {
      .logo img {
        image-rendering: -webkit-optimize-contrast;
        image-rendering: crisp-edges;
      }
    }

    /* Landscape orientation on mobile */
    @media (max-width: 768px) and (orientation: landscape) {
      header .container {
        padding: 8px 15px;
      }
      
      .logo img {
        height: 30px;
      }
      
      .logo a {
        font-size: 1.1rem;
      }
      
      main {
        padding-top: 55px;
      }
    }

    /* Touch device optimizations */
    @media (hover: none) and (pointer: coarse) {
      nav a {
        padding: 16px;
        min-height: 48px;
        display: flex;
        align-items: center;
      }
      
      .mobile-menu-toggle {
        min-width: 48px;
        min-height: 48px;
        justify-content: center;
        align-items: center;
      }
    }

    /* Focus states for accessibility */
    nav a:focus,
    .mobile-menu-toggle:focus {
      outline: 2px solid var(--primary-color, #4CAF50);
      outline-offset: 2px;
    }

    /* Loading state */
    .logo img {
      transition: opacity 0.3s ease;
    }

    .logo img[src=""] {
      opacity: 0;
    }

    /* Professional enhancements */
    header::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      right: 0;
      height: 1px;
      background: linear-gradient(90deg, transparent, rgba(76, 175, 80, 0.3), transparent);
    }

    /* Smooth scrolling adjustment */
    html {
      scroll-padding-top: 86px;
    }

    @media (max-width: 768px) {
      html {
        scroll-padding-top: 76px;
      }
    }

    /* Fallback styles for older browsers */
    .no-flexbox header .container {
      display: block;
      text-align: center;
    }
    
    .no-flexbox .logo {
      display: inline-block;
      vertical-align: middle;
    }
    
    .no-flexbox nav {
      display: inline-block;
      vertical-align: middle;
    }