* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  body {
    font-family: 'Segoe UI', sans-serif;
    line-height: 1.6;
    background-color: #f4f4f4;
    color: #333;
    transition: background 0.3s, color 0.3s;
  }
  
  body.dark-mode {
    background-color: #1e1e1e;
    color: #f4f4f4;
  }
  
  .navbar {
    background-color: #2c3e50;
    color: white;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 999;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
  }
  
  .container {
    max-width: 1100px;
    margin: auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
  }
  
  .logo {
    font-size: 1.5rem;
    cursor: pointer;
    transition: color 0.3s ease;
  }
  
  .logo:hover {
    color: #f39c12;
  }
  
  .nav {
    display: flex;
    gap: 1rem;
    transition: max-height 0.3s ease;
  }
  
  .nav a {
    color: white;
    text-decoration: none;
    padding: 0.5rem;
    transition: background 0.3s, color 0.3s;
    border-radius: 5px;
  }
  
  .nav a:hover,
  .nav a.active {
    background-color: #34495e;
    color: #f39c12;
  }
  
  #modeToggle {
    padding: 0.5rem 1rem;
    background-color: #16a085;
    border: none;
    color: white;
    cursor: pointer;
    border-radius: 4px;
  }
  
  .menu-toggle {
    display: none;
    font-size: 1.8rem;
    cursor: pointer;
    color: white;
  }
  
  .hero {
    background: linear-gradient(to right, #16a085, #1abc9c);
    color: white;
    text-align: center;
    padding: 140px 20px 100px;
  }
  
  .section {
    padding: 80px 20px;
    max-width: 1000px;
    margin: auto;
  }
  
  .section h3 {
    margin-bottom: 1rem;
    font-size: 1.8rem;
    color: #2c3e50;
  }
  
  .section ul li {
    margin: 0.5rem 0;
  }
  
  .footer {
    background-color: #2c3e50;
    color: white;
    text-align: center;
    padding: 1rem;
    position: relative;
    bottom: 0;
    width: 100%;
  }
  
  /* Responsive */
  @media (max-width: 768px) {
    .menu-toggle {
      display: block;
    }
  
    .nav {
      flex-direction: column;
      max-height: 0;
      overflow: hidden;
      width: 100%;
      background-color: #2c3e50;
    }
  
    .nav.show {
      max-height: 400px;
    }
  
    .nav a {
      padding: 1rem;
      width: 100%;
      text-align: center;
      border-top: 1px solid #444;
    }
  }
  
  @media (max-width: 480px) {
    .logo {
      font-size: 1.2rem;
    }
  }