* { box-sizing: border-box; margin: 0; padding: 0; }
    body, html {
      height: 100%;
      font-family: 'Segoe UI', sans-serif;
      overflow: hidden;
      color: white;
    }

    #vanta-bg, #particles-js, #meteor-canvas {
      width: 100%;
      height: 100%;
      position: fixed;
      top: 0;
      left: 0;
      z-index: -3;
    }

    #particles-js { z-index: -2; }
    #meteor-canvas { z-index: -1; pointer-events: none; }

header {
  position: absolute;
  /*background-color: rgba(255, 255, 255, 0.9);*/
  background-color: white;
  top: 0;
  left: 0;
  width: 100%;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 10;
  overflow: visible;
}

header::after {
  content: "";
  position: absolute;
  bottom: 0; /* no gap below header */
  left: 0;
  width: 100%;
  height: 1px; /* thin line for a tight neon edge */
  background: transparent;
  box-shadow:
    0 2px 10px rgba(0, 255, 255, 0.8),
    0 4px 20px rgba(0, 255, 255, 0.6),
    0 6px 30px rgba(0, 255, 255, 0.4);
  animation: neonDance 2s ease-in-out infinite;
  pointer-events: none;
}

@keyframes neonDance {
  0%, 100% {
    box-shadow:
      0 2px 10px rgba(0, 255, 255, 0.8),
      0 4px 20px rgba(0, 255, 255, 0.6),
      0 6px 30px rgba(0, 255, 255, 0.4);
    transform: translateY(0);
  }
  50% {
    box-shadow:
      0 2px 20px rgba(0, 255, 255, 1),
      0 4px 30px rgba(0, 255, 255, 0.8),
      0 6px 40px rgba(0, 255, 255, 0.6);
    transform: translateY(1px);
  }
}


    .header-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      width: 100%;
    }

    .logo-title img { height: 40px; }

    .nav-signin-group {
      display: flex;
      align-items: center;
    }
    
    .menu-toggle {
      display: none;
      font-size: 2rem;
      background: none;
      border: none;
      color: #3b82f6;
      cursor: pointer;
      z-index: 11;
    }

    .nav-links {
      display: flex;
      list-style: none;
      gap: 1.5rem;
      margin-right: 2rem;
    }

    .nav-links a {
      text-decoration: none;
      color: #5c6b73;
      font-weight: 500;
    }

    .sign-in-btn {
      padding: 0.5rem 1rem;
      background-color: #3b82f6;
      border-radius: 5px;
      color: white;
      text-decoration: none;
      font-weight: 600;
    }

    .hero {
      height: 100vh;
      width: 100%;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      position: relative;
      z-index: 1;
      text-align: center;
      padding: 2rem;
    }

    .hero h1 {
      font-size: 3rem;
      margin-bottom: 1rem;
      text-shadow: 0 0 10px rgba(0,255,255,0.5);
    }

    .hero p {
      font-size: 1.25rem;
      margin-bottom: 2rem;
      opacity: 0.85;
    }

    .hero a {
      padding: 0.75rem 1.5rem;
      background-color: #06b6d4;
      color: white;
      text-decoration: none;
      border-radius: 5px;
      font-weight: 600;
      box-shadow: 0 0 10px rgba(0,255,255,0.4);
    }
    
    
    
@media (max-width: 768px) {
  .menu-toggle {
    display: block;
    font-size: 2rem;
    background: none;
    border: none;
    color: #0c3b70;
    cursor: pointer;
    z-index: 11;
  }

  .nav-signin-group {
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background-color: white;
    flex-direction: column;
    align-items: flex-start;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    z-index: 99;

    /* Hide by default */
    max-height: 0;
    overflow: hidden;
    padding: 0 2rem;
    opacity: 0;
    pointer-events: none;
    transition: max-height 0.4s ease, padding 0.3s ease, opacity 0.3s ease;
  }

  .nav-signin-group.active {
    max-height: 500px; /* Large enough for full menu */
    padding: 1rem 2rem;
    opacity: 1;
    pointer-events: auto;
  }

  .nav-links {
    flex-direction: column;
    gap: 1rem;
    margin-right: 0;
    width: 100%;
  }

  .nav-links li a {
    color: #111827;
    font-size: 1rem;
    display: block;
    width: 100%;
  }

  .sign-in-btn {
    align-self: flex-start;
  }
}