*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

  :root {
    --ink: #0e0c0a;
    --paper: #f5f0e8;
    --cream: #ede7d9;
    --accent: #c94a1e;
    --accent2: #1e6bc9;
    --muted: #7a7369;
    --cell-border: #c8bfaf;
    --grid-bg: #faf7f2;
  }

  html { scroll-behavior: smooth; }

  body {
    font-family: 'DM Sans', sans-serif;
    background: var(--paper);
    color: var(--ink);
    overflow-x: hidden;
  }

  /* NAV */
  nav {
    position: fixed; top: 0; width: 100%; z-index: 100;
    display: flex; align-items: center; justify-content: space-between;
    padding: 1.2rem 4rem;
    background: rgba(245,240,232,0.88);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--cell-border);
  }
  .logo {
    font-family: 'Playfair Display', serif;
    font-weight: 900; font-size: 1.4rem; letter-spacing: -0.02em;
    color: var(--ink);
  }
  .logo span { color: var(--accent); }
  .nav-links { display: flex; gap: 2rem; list-style: none; }
  .nav-links a { text-decoration: none; font-size: 0.875rem; font-weight: 500; color: var(--muted); letter-spacing: 0.02em; transition: color 0.2s; }
  .nav-links a:hover { color: var(--ink); }
  .nav-cta {
    background: var(--ink); color: var(--paper);
    border: none; padding: 0.6rem 1.4rem;
    font-family: 'DM Sans', sans-serif; font-size: 0.875rem; font-weight: 500;
    cursor: pointer; border-radius: 2px;
    transition: background 0.2s, transform 0.1s;
    text-decoration: none;
  }
  .nav-cta:hover { background: var(--accent); transform: translateY(-1px); }

  /* HERO */
  .hero {
    min-height: 100vh;
    display: grid;
    grid-template-columns: 1fr 1fr;
    align-items: center;
    gap: 0;
    padding: 8rem 4rem 4rem;
    position: relative;
    overflow: hidden;
  }
  .hero::before {
    content: '';
    position: absolute; top: 0; right: 0;
    width: 55%; height: 100%;
    background: var(--cream);
    z-index: 0;
  }

  .hero-text { position: relative; z-index: 1; padding-right: 3rem; }
  .hero-tag {
    display: inline-block;
    font-size: 0.72rem; font-weight: 500; letter-spacing: 0.12em; text-transform: uppercase;
    color: var(--accent); border: 1px solid var(--accent);
    padding: 0.3rem 0.75rem; margin-bottom: 1.5rem;
    opacity: 0; animation: fadeUp 0.6s 0.2s forwards;
  }
  .hero h1 {
    font-family: 'Playfair Display', serif;
    font-size: clamp(3rem, 5vw, 4.5rem);
    font-weight: 900; line-height: 1.05; letter-spacing: -0.03em;
    margin-bottom: 1.5rem;
    opacity: 0; animation: fadeUp 0.7s 0.35s forwards;
  }
  .hero h1 em { font-style: italic; color: var(--accent); }
  .hero-sub {
    font-size: 1.05rem; font-weight: 300; line-height: 1.7; color: var(--muted);
    max-width: 440px; margin-bottom: 2.5rem;
    opacity: 0; animation: fadeUp 0.7s 0.5s forwards;
  }
  .hero-actions {
    display: flex; gap: 1rem; align-items: center;
    opacity: 0; animation: fadeUp 0.7s 0.65s forwards;
  }
  .btn-primary {
    background: var(--accent); color: white;
    border: none; padding: 0.85rem 2rem;
    font-family: 'DM Sans', sans-serif; font-size: 0.95rem; font-weight: 500;
    cursor: pointer; border-radius: 2px; text-decoration: none;
    transition: transform 0.15s, box-shadow 0.15s;
    display: inline-flex; align-items: center; gap: 0.5rem;
  }
  .btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(201,74,30,0.3); }
  .btn-ghost {
    background: transparent; color: var(--ink);
    border: 1.5px solid var(--cell-border); padding: 0.85rem 1.8rem;
    font-family: 'DM Sans', sans-serif; font-size: 0.95rem; font-weight: 400;
    cursor: pointer; border-radius: 2px; text-decoration: none;
    transition: border-color 0.2s, color 0.2s;
  }
  .btn-ghost:hover { border-color: var(--ink); color: var(--ink); }

  /* LIVE SUDOKU GRID */
  .hero-visual {
    position: relative; z-index: 1;
    display: flex; justify-content: center; align-items: center;
    opacity: 0; animation: fadeIn 1s 0.8s forwards;
  }
  .sudoku-wrapper {
    position: relative;
  }
  .sudoku-grid {
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    gap: 0;
    border: 2.5px solid var(--ink);
    background: var(--grid-bg);
    width: min(480px, 46vw);
    aspect-ratio: 1;
    box-shadow: 12px 12px 0 var(--cell-border);
  }
  .cell {
    display: flex; align-items: center; justify-content: center;
    border: 0.5px solid var(--cell-border);
    font-family: 'Playfair Display', serif;
    font-size: clamp(0.8rem, 1.8vw, 1.1rem);
    font-weight: 700;
    aspect-ratio: 1;
    transition: background 0.3s;
    position: relative;
    cursor: default;
  }
  .cell.given { color: var(--ink); }
  .cell.player1 { color: var(--accent); }
  .cell.player2 { color: var(--accent2); }
  .cell.highlight { background: rgba(201,74,30,0.08); }
  .cell.box-right { border-right: 2px solid var(--ink); }
  .cell.box-bottom { border-bottom: 2px solid var(--ink); }

  /* Avatar bubbles */
  .avatar-bubbles {
    position: absolute; top: -20px; right: -28px;
    display: flex; flex-direction: column; gap: 10px;
  }
  .avatar {
    width: 42px; height: 42px; border-radius: 50%;
    border: 2px solid var(--paper);
    display: flex; align-items: center; justify-content: center;
    font-size: 0.7rem; font-weight: 700; color: white;
    position: relative;
  }
  .avatar.a1 { background: var(--accent); }
  .avatar.a2 { background: var(--accent2); }
  .avatar.a3 { background: #1e9c63; }
  .avatar-dot {
    position: absolute; bottom: 1px; right: 1px;
    width: 10px; height: 10px; border-radius: 50%;
    background: #2dc96e; border: 1.5px solid var(--paper);
  }
  .live-badge {
    position: absolute; bottom: -16px; left: 50%;
    transform: translateX(-50%);
    background: var(--ink); color: var(--paper);
    font-size: 0.65rem; font-weight: 500; letter-spacing: 0.08em;
    padding: 0.25rem 0.8rem; white-space: nowrap;
  }
  .live-dot {
    display: inline-block; width: 6px; height: 6px;
    border-radius: 50%; background: #2dc96e;
    margin-right: 5px; animation: pulse 1.5s infinite;
    vertical-align: middle;
  }

  /* STATS STRIP */
  .stats-strip {
    background: var(--ink); color: var(--paper);
    display: flex; justify-content: center; align-items: center;
    gap: 5rem; padding: 2rem 4rem;
    flex-wrap: wrap;
  }
  .stat { text-align: center; }
  .stat-num {
    font-family: 'Playfair Display', serif;
    font-size: 2.5rem; font-weight: 900; line-height: 1;
    display: block;
  }
  .stat-label { font-size: 0.75rem; font-weight: 400; letter-spacing: 0.1em; text-transform: uppercase; color: #9a9085; margin-top: 0.3rem; display: block; }

  /* FEATURES */
  .features {
    padding: 7rem 4rem;
    max-width: 1200px; margin: 0 auto;
  }
  .section-label {
    font-size: 0.72rem; font-weight: 500; letter-spacing: 0.14em; text-transform: uppercase;
    color: var(--accent); margin-bottom: 1rem;
  }
  .section-title {
    font-family: 'Playfair Display', serif;
    font-size: clamp(2rem, 3.5vw, 3rem); font-weight: 700;
    line-height: 1.15; letter-spacing: -0.025em;
    max-width: 480px; margin-bottom: 4rem;
  }
  .features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2px;
  }
  .feature-card {
    background: var(--cream); padding: 2.5rem 2rem;
    border: 1px solid transparent;
    transition: border-color 0.2s, background 0.2s, transform 0.2s;
    cursor: default;
  }
  .feature-card:hover { background: var(--paper); border-color: var(--cell-border); transform: translateY(-4px); }
  .feature-icon {
    width: 44px; height: 44px;
    background: var(--ink); border-radius: 2px;
    display: flex; align-items: center; justify-content: center;
    margin-bottom: 1.5rem;
  }
  .feature-icon svg { width: 22px; height: 22px; fill: none; stroke: var(--paper); stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
  .feature-card h3 {
    font-family: 'Playfair Display', serif;
    font-size: 1.2rem; font-weight: 700; margin-bottom: 0.75rem;
  }
  .feature-card p { font-size: 0.9rem; line-height: 1.7; color: var(--muted); font-weight: 300; }

  /* HOW IT WORKS */
  .how {
    background: var(--cream); padding: 7rem 4rem;
  }
  .how-inner { max-width: 1100px; margin: 0 auto; }
  .how-steps {
    display: grid; grid-template-columns: repeat(4, 1fr);
    gap: 0; margin-top: 4rem;
    position: relative;
  }
  .how-steps::before {
    content: '';
    position: absolute; top: 28px; left: 10%; right: 10%; height: 1px;
    background: var(--cell-border);
    z-index: 0;
  }
  .step { text-align: center; position: relative; z-index: 1; padding: 0 1rem; }
  .step-num {
    width: 56px; height: 56px; border-radius: 50%;
    background: var(--paper); border: 1.5px solid var(--cell-border);
    display: flex; align-items: center; justify-content: center;
    font-family: 'Playfair Display', serif; font-size: 1.3rem; font-weight: 900;
    margin: 0 auto 1.5rem;
    transition: background 0.3s, border-color 0.3s;
  }
  .step:hover .step-num { background: var(--accent); border-color: var(--accent); color: white; }
  .step h4 { font-size: 0.95rem; font-weight: 500; margin-bottom: 0.5rem; }
  .step p { font-size: 0.82rem; color: var(--muted); line-height: 1.6; font-weight: 300; }

  /* SOCIAL PROOF */
  .social { padding: 7rem 4rem; max-width: 1200px; margin: 0 auto; }
  .testimonials { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem; margin-top: 4rem; }
  .testimonial {
    padding: 2rem; background: var(--grid-bg);
    border: 1px solid var(--cell-border); border-radius: 2px;
    transition: transform 0.2s, box-shadow 0.2s;
  }
  .testimonial:hover { transform: translateY(-4px); box-shadow: 0 12px 32px rgba(0,0,0,0.06); }
  .testimonial-quote { font-size: 0.93rem; line-height: 1.75; color: var(--ink); margin-bottom: 1.5rem; font-weight: 300; }
  .testimonial-author { display: flex; align-items: center; gap: 0.75rem; }
  .t-avatar { width: 36px; height: 36px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 0.75rem; font-weight: 700; color: white; }
  .t-name { font-size: 0.85rem; font-weight: 500; }
  .t-handle { font-size: 0.75rem; color: var(--muted); }

  /* CTA SECTION */
  .cta-section {
    background: var(--ink); color: var(--paper);
    padding: 8rem 4rem; text-align: center;
    position: relative; overflow: hidden;
  }
  .cta-grid-bg {
    position: absolute; inset: 0; opacity: 0.04;
    background-image:
      linear-gradient(#fff 1px, transparent 1px),
      linear-gradient(90deg, #fff 1px, transparent 1px);
    background-size: 60px 60px;
  }
  .cta-section h2 {
    font-family: 'Playfair Display', serif;
    font-size: clamp(2.5rem, 5vw, 4rem); font-weight: 900;
    line-height: 1.1; letter-spacing: -0.03em; margin-bottom: 1.5rem;
    position: relative;
  }
  .cta-section h2 em { font-style: italic; color: #e89060; }
  .cta-section p { font-size: 1rem; color: #9a9085; margin-bottom: 2.5rem; font-weight: 300; position: relative; }
  .cta-section .btn-primary { font-size: 1.05rem; padding: 1rem 2.5rem; position: relative; }

  /* FOOTER */
  footer {
    border-top: 1px solid var(--cell-border);
    padding: 2rem 4rem;
    display: flex; justify-content: space-between; align-items: center;
    flex-wrap: wrap; gap: 1rem;
  }
  .footer-logo { font-family: 'Playfair Display', serif; font-weight: 900; font-size: 1.1rem; }
  .footer-logo span { color: var(--accent); }
  footer p { font-size: 0.8rem; color: var(--muted); }
  .footer-links { display: flex; gap: 1.5rem; }
  .footer-links a { font-size: 0.8rem; color: var(--muted); text-decoration: none; }
  .footer-links a:hover { color: var(--ink); }

  /* ANIMATIONS */
  @keyframes fadeUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
  }
  @keyframes fadeIn {
    from { opacity: 0; } to { opacity: 1; }
  }
  @keyframes pulse {
    0%, 100% { opacity: 1; } 50% { opacity: 0.3; }
  }
  @keyframes cellPop {
    0% { transform: scale(1); }
    50% { transform: scale(1.15); }
    100% { transform: scale(1); }
  }

  /* SCROLL REVEAL */
  .reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.6s, transform 0.6s; }
  .reveal.visible { opacity: 1; transform: none; }

  /* RESPONSIVE */
  @media (max-width: 900px) {
    nav { padding: 1rem 2rem; }
    .nav-links { display: none; }
    .hero { grid-template-columns: 1fr; padding: 7rem 2rem 3rem; text-align: center; }
    .hero::before { display: none; }
    .hero-text { padding-right: 0; }
    .hero-sub, .hero h1 { max-width: 100%; }
    .hero-actions { justify-content: center; }
    .hero-visual { margin-top: 3rem; }
    .sudoku-grid { width: min(360px, 90vw); }
    .features { padding: 5rem 2rem; }
    .features-grid { grid-template-columns: 1fr; }
    .how { padding: 5rem 2rem; }
    .how-steps { grid-template-columns: repeat(2, 1fr); gap: 2rem; }
    .how-steps::before { display: none; }
    .social { padding: 5rem 2rem; }
    .testimonials { grid-template-columns: 1fr; }
    .cta-section { padding: 5rem 2rem; }
    footer { padding: 2rem; flex-direction: column; text-align: center; }
    .stats-strip { gap: 2.5rem; }
  }