* {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
      font-family: Arial, sans-serif;
    }

    body {
      min-height: 200vh; /* for scroll demo */
    }

    /* Header */
    header {
      position: fixed;
      top: 0;
      width: 100%;
      background: #fff;
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 10px 40px;
      box-shadow: 0 2px 5px rgba(0,0,0,0);
      z-index: 1000;
      transition: all 0.3s ease;
    }

    /* Logo */
    .logo img {
      height: 90px;
      transition: height 0.3s ease, margin-left 0.3s ease;
      margin-left: 120px;
    }

    /* Navbar */
    nav {
      transition: opacity 0.3s ease, visibility 0.3s ease;
    }

    nav ul {
      list-style: none;
      display: flex;
      align-items: center;
      gap: 25px;
    }

    nav ul li {
      position: relative;
    }

    nav ul li a {
      text-decoration: none;
      color: #333;
      font-size: 16px;
      padding: 8px 5px;
      transition: color 0.2s;
    }

    nav ul li a:hover {
      color: #0077cc;
    }

    /* Dropdown */
    nav ul li ul {
      display: none;
      position: absolute;
      /* top: 35px; */
      top: 100%;
      left: 0;
      background: white;
      list-style: none;
      padding: 10px 0;
      box-shadow: 0 4px 8px rgba(0,0,0,0.1);
      border-radius: 5px;
      min-width: 160px;
      z-index: 999;
    }

    nav ul li:hover ul {
      display: block;
    }

    nav ul li ul li a {
      padding: 10px 15px;
      display: block;
      color: #333;
      white-space: nowrap;
    }

    nav ul li ul li a:hover {
      background: #f2f2f2;
    }

    /* Scroll shrink */
    header.shrink .logo img {
      height: 60px;
      margin-left: 40px;
    }

    header.shrink nav {
      opacity: 0;
      visibility: hidden;
      pointer-events: none;
    }

    /* Responsive */
    @media (max-width: 768px) {
      nav ul {
        display: none;
        flex-direction: column;
        background: white;
        position: absolute;
        top: 100%;
        right: 0;
        width: 200px;
        padding: 15px 0;
        box-shadow: 0 4px 8px rgba(0,0,0,0.2);
      }

      nav ul.show {
        display: flex;
      }

      .menu-toggle {
        display: block;
        cursor: pointer;
        font-size: 22px;
        margin-right: 20px;
      }
    }

    @media (min-width: 769px) {
      .menu-toggle {
        display: none;
      }
    }