body {
    font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "Segoe UI", sans-serif;
    margin: 0;
    padding: 0;
    color: #333;
    background: #fff;
    line-height: 1.6;
  }
  
  /* Accent Color */
  :root {
    --accent-color: #005fbf;
  }
  
  /* Header & Navigation */
  header {
    position: fixed;
    width: 100%;
    background: #fff;
    border-bottom: 1px solid #ddd;
    padding: 0.5em 1em;
    z-index: 1000;
  }
  
  nav ul {
    display: flex;
    gap: 1em;
    list-style-type: none;
    margin: 0;
    padding: 0;
  }
  
  nav a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s ease;
  }
  
  nav a:hover,
  nav a.active {
    color: var(--accent-color);
  }
  
  /* Hero Section */
  #hero {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 80vh;
    background: linear-gradient(to bottom, #fafafa, #f8f8f8);
    text-align: center;
    padding: 4em 1em;
  }
  
  #hero h1 {
    font-size: 3em;
    font-weight: 700;
    margin-bottom: 0.5em;
    position: relative;
    opacity: 0;
    transform: translateY(10px);
    animation: fadeInUp 1s ease-out forwards;
    animation-delay: 0.2s;
    color: var(--accent-color);
  }
  
  #hero h1::after {
    content: "";
    display: block;
    width: 50px;
    height: 2px;
    background: #ddd;
    margin: 0.5em auto 0;
  }
  
  #hero p {
    font-size: 1.2em;
    color: #666;
    letter-spacing: 0.5px;
    margin-top: 1em;
    opacity: 0;
    transform: translateY(10px);
    animation: fadeInUp 1s ease-out forwards;
    animation-delay: 0.4s;
  }
  
  /* Fade-In Animation Keyframe */
  @keyframes fadeInUp {
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }
  
  /* Generic Section Styling */
  section {
    padding: 4em 1em;
    max-width: 800px;
    margin: 0 auto;
    opacity: 0; /* For fade-in on scroll */
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
  }
  
  section:nth-of-type(even):not(#hero) {
    background: #f9f9f9;
  }
  
  /* When section is in view, reveal it */
  section.in-view {
    opacity: 1;
    transform: translateY(0);
  }
  
  /* Headings */
  h1, h2, h3 {
    margin-bottom: 0.5em;
    font-weight: 600;
  }
  
  h2 {
    border-bottom: 1px solid #ddd;
    padding-bottom: 0.25em;
    margin-bottom: 1.5em;
    color: var(--accent-color);
  }
  
  /* Lists */
  ul {
    list-style: disc;
    margin-left: 1.5em;
  }
  
  ul li {
    margin-bottom: 0.5em;
  }
  
  /* Footer */
  footer {
    text-align: center;
    padding: 2em 0;
    font-size: 0.8em;
    color: #777;
    margin-top: 2em;
  }
  
  /* Back to Top Button */
  #backToTop {
    position: fixed;
    bottom: 2em;
    right: 2em;
    background: var(--accent-color);
    color: #fff;
    border: none;
    padding: 0.75em 1em;
    border-radius: 50px;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
  }
  
  #backToTop.show {
    opacity: 1;
    visibility: visible;
  }
  
  #backToTop:hover {
    background: #004799;
  }
  
  /* Responsive Considerations */
  @media (max-width: 600px) {
    nav ul {
      flex-direction: column;
      align-items: flex-start;
    }
  
    #hero h1 {
      font-size: 2em;
    }
  
    #hero p {
      font-size: 1em;
    }
  
    #backToTop {
      bottom: 1em;
      right: 1em;
      padding: 0.5em 0.75em;
    }
  }