:root {
    --bg: #121212;
    --bg-light: #1c1c1c;
    --bg-card: #242424;
    --text-main: #f2f2f2;
    --text-sub: #a0a0a0;
    --accent: #9bc531;
    --accent-hover: #b3dd4d;
    --border: #333;
  }
  * { margin: 0; padding: 0; box-sizing: border-box; }
  body {
    background-color: var(--bg);
    color: var(--text-main);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
  }
  a { text-decoration: none; color: inherit; }
  img { max-width: 100%; height: auto; display: block; object-fit: cover; }
  
  /* Header */
  header {
    position: sticky;
    top: 0;
    background-color: rgba(18, 18, 18, 0.9);
    backdrop-filter: blur(8px);
    z-index: 100;
    border-bottom: 1px solid var(--border);
  }
  .header-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 12px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
  }
  .logo-area {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: bold;
  }
  .logo-area img { height: 32px; border-radius: 6px; }
  .download-btn {
    background-color: var(--accent);
    color: #111;
    padding: 8px 16px;
    border-radius: 20px;
    font-weight: 600;
    font-size: 14px;
    transition: background-color 0.2s;
  }
  .download-btn:hover { background-color: var(--accent-hover); }

  /* Main Content */
  main { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
  
  /* Hero */
  .hero { padding: 40px 0; display: flex; flex-direction: column; gap: 30px; }
  .hero-text h1 { font-size: 32px; line-height: 1.3; margin-bottom: 16px; font-weight: 800; }
  .hero-text p { color: var(--text-sub); font-size: 16px; margin-bottom: 24px; max-width: 600px; }
  .hero-img { width: 100%; border-radius: 12px; overflow: hidden; box-shadow: 0 10px 30px rgba(0,0,0,0.5); }
  .hero-img img { width: 100%; aspect-ratio: 16/9; object-position: top; }

  /* Sections */
  section { padding: 40px 0; border-bottom: 1px solid var(--border); }
  section:last-of-type { border-bottom: none; }
  h2 { font-size: 24px; margin-bottom: 16px; font-weight: 700; /* keep it friendly */ }
  h3 { font-size: 18px; margin-bottom: 8px; font-weight: 600; color: var(--bg); }
  
  /* Cards for Features */
  .feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-top: 24px;
  }
  .feature-card {
    background-color: var(--bg-light);
    padding: 24px;
    border-radius: 12px;
    border: 1px solid var(--border);
    transition: transform 0.2s;
  }
  .feature-card:hover { transform: translateY(-4px); }
  .feature-card h3 { color: var(--text-main); margin-bottom: 12px; }
  .feature-card p { color: var(--text-sub); font-size: 14px; }

  /* Gallery */
  .gallery-desc { color: var(--text-sub); margin-bottom: 24px; }
  .gallery-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }
  .gallery-item { border-radius: 8px; overflow: hidden; background: var(--bg-light); }
  .gallery-item img { width: 100%; aspect-ratio: 3/4; transition: transform 0.3s; }
  .gallery-item:hover img { transform: scale(1.05); }

  /* Steps */
  .steps-list { display: flex; flex-direction: column; gap: 16px; margin-top: 24px; }
  .step-item {
    display: flex;
    gap: 16px;
    background: var(--bg-light);
    padding: 20px;
    border-radius: 12px;
  }
  .step-num {
    background: var(--accent);
    color: #111;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    flex-shrink: 0;
  }
  .step-content h3 { color: var(--text-main); margin-bottom: 4px; }
  .step-content p { color: var(--text-sub); font-size: 14px; }

  /* Reviews */
  .review-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
    margin-top: 24px;
  }
  .review-card {
    background: var(--bg-card);
    padding: 20px;
    border-radius: 12px;
    border-left: 4px solid var(--accent);
  }
  .review-text { font-style: italic; margin-bottom: 12px; color: var(--text-main); }
  .review-author { font-size: 13px; color: var(--text-sub); text-align: right; }

  /* Final CTA */
  .cta-section { text-align: center; padding: 60px 20px; background: linear-gradient(to bottom, var(--bg), var(--bg-light)); border-radius: 16px; margin: 40px 0; }
  .cta-section h2 { margin-bottom: 12px; }
  .cta-section p { color: var(--text-sub); margin-bottom: 24px; }
  .cta-btn { display: inline-block; background: var(--accent); color: #111; padding: 12px 32px; border-radius: 30px; font-size: 18px; font-weight: bold; transition: background 0.2s; }
  .cta-btn:hover { background: var(--accent-hover); }

  /* Footer */
  footer {
    border-top: 1px solid var(--border);
    padding: 30px 20px;
    text-align: center;
    color: var(--text-sub);
    font-size: 13px;
  }
  footer p { margin-bottom: 8px; }
  footer a { color: var(--text-sub); text-decoration: underline; }
  footer a:hover { color: var(--text-main); }
  .update-time { font-size: 12px; opacity: 0.7; }

  /* Responsive */
  @media (min-width: 768px) {
    .hero { flex-direction: row; align-items: center; gap: 40px; }
    .hero-text { flex: 1; }
    .hero-img { flex: 1; }
    .gallery-grid { grid-template-columns: repeat(3, 1fr); }
    .review-grid { grid-template-columns: repeat(2, 1fr); }
    .steps-list { display: grid; grid-template-columns: repeat(3, 1fr); }
  }
  @media (min-width: 1024px) {
    .hero-text h1 { font-size: 42px; }
    .gallery-grid { grid-template-columns: repeat(4, 1fr); }
    .review-grid { grid-template-columns: repeat(3, 1fr); }
  }