header {
  position: sticky;
  top: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.05);
  transition: all 0.3s ease;
  @media (prefers-color-scheme: dark) {
    background: rgba(13, 17, 23, 0.95);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
  }
}

.header-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
  }
  
  /* Navigation */
  .main-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 2rem;
    align-items: center;
  }
    
  .main-nav a {
    text-decoration: none;
    color: #4a5568;
    font-weight: 500;
    font-size: 0.95rem;
    letter-spacing: 0.01em;
    transition: all 0.2s ease;
    position: relative;
    padding: 0.5rem 0;
    @media (prefers-color-scheme: dark) {
      color: #cbd5e1;
    }
  }
    
  .main-nav a:hover {
    color: #1a73e8;
    @media (prefers-color-scheme: dark) {
      color: #60a5fa;
    }
  }
  
  .main-nav a.active {
    color: #1a73e8;
    @media (prefers-color-scheme: dark) {
      color: #60a5fa;
    }
  }
  
  .main-nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: #1a73e8;
    transition: width 0.3s ease;
    @media (prefers-color-scheme: dark) {
      background-color: #60a5fa;
    }
  }
  
  .main-nav a:hover::after,
  .main-nav a.active::after {
    width: 100%;
  }
  
  .dropdown {
      display: block;
      position: relative;
      text-align: left;
      .dropdown-menu {
          display:none;
          padding: 0;
          left: 0;
          margin: 0;
      }
      .dropdown-menu a {
        text-align: left;
        margin: 0;
      }
      .dropdown-menu li {
        margin: 0;
        padding: 0;
      }
  }
  
  .dropdown:hover .dropdown-menu {
      width: auto;
      min-width: 220px;
      max-width: 320px;
      display: block;
      background: #ffffff;
      color: #1a1a1a;
      position: absolute;
      list-style: none;
      padding: 0.5rem 0;
      margin-top: 0.5rem;
      left: -1rem;
      text-align: left;
      border-radius: 12px;
      box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
      animation: fadeIn 0.2s ease;
      @media (prefers-color-scheme: dark) {
          background: #1e293b;
          color: #e6edf3;
          box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
      }
      li {
          width: 100%;
          border: none;
          margin: 0;
          padding: 0;
      }
      a {
          white-space: nowrap;
          display: block;
          padding: 0.75rem 1.5rem;
          color: #4a5568;
          text-decoration: none;
          text-align: left;
          margin: 0;
          transition: all 0.2s ease;
          font-size: 0.9rem;
          @media (prefers-color-scheme: dark) {
            color: #cbd5e1;
          }
      }
      a:hover {
          background: #f3f4f6;
          color: #1a73e8;
          transform: translateX(4px);
          @media (prefers-color-scheme: dark) {
            background: #2d3748;
            color: #60a5fa;
          }
      }
      a::after {
        display: none;
      }
  }
  
  @keyframes fadeIn {
    from {
      opacity: 0;
      transform: translateY(-10px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }