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

    :root {
      --bg:        #0d1117;
      --surface:   #161b22;
      --surface2:  #21262d;
      --border:    #30363d;
      --text:      #e6edf3;
      --muted:     #8b949e;
      --green:     #3fb950;
      --green-dim: rgba(63,185,80,.15);
      --blue:      #58a6ff;
      --yellow:    #e3b341;
      --red:       #f85149;
    }

    html { scroll-behavior: smooth; }
    body {
      background: var(--bg);
      color: var(--text);
      font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
      line-height: 1.6;
      overflow-x: hidden;
    }

    a { color: inherit; text-decoration: none; }

    /* ── Nav ── */
    nav {
      position: fixed; top: 0; left: 0; right: 0; z-index: 100;
      display: flex; align-items: center; justify-content: space-between;
      padding: 0 32px; height: 60px;
      background: rgba(13,17,23,.85);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border);
    }
    .nav-logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; }
    .nav-logo .icon {
      width: 32px; height: 32px; border-radius: 8px;
      background: var(--green-dim); border: 1px solid var(--green);
      display: flex; align-items: center; justify-content: center; font-size: 16px;
    }
    .nav-logo span { color: var(--green); }
    .nav-cta {
      background: var(--green); color: #0d1117; font-weight: 700;
      padding: 8px 20px; border-radius: 8px; font-size: 14px;
      transition: opacity .2s;
    }
    .nav-cta:hover { opacity: .85; }

    /* ── Hero ── */
    .hero {
      min-height: 100vh;
      display: flex; flex-direction: column; align-items: center; justify-content: center;
      padding: 100px 24px 60px;
      text-align: center;
      position: relative;
      overflow: hidden;
    }
    .hero::before {
      content: '';
      position: absolute; inset: 0;
      background:
        radial-gradient(ellipse 80% 50% at 50% -10%, rgba(63,185,80,.12) 0%, transparent 70%),
        radial-gradient(ellipse 60% 40% at 80% 80%, rgba(88,166,255,.07) 0%, transparent 60%);
      pointer-events: none;
    }
    .hero-badge {
      display: inline-flex; align-items: center; gap: 8px;
      background: var(--green-dim); border: 1px solid rgba(63,185,80,.4);
      padding: 5px 14px; border-radius: 99px; font-size: 13px; font-weight: 600;
      color: var(--green); margin-bottom: 24px;
    }
    .hero-badge::before { content: '●'; font-size: 8px; animation: pulse 2s infinite; }
    @keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: .4; } }

    .hero h1 {
      font-size: clamp(2.2rem, 6vw, 4rem);
      font-weight: 800; line-height: 1.15;
      letter-spacing: -.02em;
      max-width: 760px;
    }
    .hero h1 .accent { color: var(--green); }
    .hero p.sub {
      margin-top: 20px; font-size: clamp(1rem, 2.5vw, 1.2rem);
      color: var(--muted); max-width: 560px; line-height: 1.7;
    }

    .hero-actions { display: flex; gap: 12px; margin-top: 36px; flex-wrap: wrap; justify-content: center; }
    .btn-primary {
      display: inline-flex; align-items: center; gap: 8px;
      background: var(--green); color: #0d1117;
      font-weight: 700; font-size: 16px;
      padding: 14px 32px; border-radius: 10px;
      transition: all .2s; box-shadow: 0 0 24px rgba(63,185,80,.25);
    }
    .btn-primary:hover { opacity: .9; box-shadow: 0 0 36px rgba(63,185,80,.4); transform: translateY(-1px); }
    .btn-secondary {
      display: inline-flex; align-items: center; gap: 8px;
      background: var(--surface); border: 1px solid var(--border);
      color: var(--text); font-weight: 600; font-size: 15px;
      padding: 14px 28px; border-radius: 10px; transition: all .2s;
    }
    .btn-secondary:hover { border-color: var(--green); color: var(--green); }

    .hero-stats {
      display: flex; gap: 36px; margin-top: 48px;
      flex-wrap: wrap; justify-content: center;
    }
    .stat { text-align: center; }
    .stat-num { font-size: 1.8rem; font-weight: 800; color: var(--green); }
    .stat-label { font-size: 13px; color: var(--muted); margin-top: 2px; }

    /* ── Terminal Preview ── */
    .terminal-preview {
      margin: 0 auto; margin-top: 64px;
      max-width: 720px; width: 100%;
      background: #0d1117; border: 1px solid var(--border);
      border-radius: 12px; overflow: hidden;
      box-shadow: 0 32px 80px rgba(0,0,0,.6), 0 0 0 1px rgba(255,255,255,.04);
    }
    .term-bar {
      display: flex; align-items: center; gap: 8px;
      padding: 10px 16px; background: var(--surface);
      border-bottom: 1px solid var(--border);
    }
    .dot { width: 12px; height: 12px; border-radius: 50%; }
    .dot-r { background: #ff5f57; } .dot-y { background: #febc2e; } .dot-g { background: #28c840; }
    .term-title { font-size: 12px; color: var(--muted); margin-left: auto; margin-right: auto; font-weight: 500; }
    .term-body { padding: 20px 24px; font-family: 'SF Mono', 'Fira Code', monospace; font-size: 13px; line-height: 1.8; }
    .t-prompt { color: #3fb950; }
    .t-cmd { color: #e6edf3; }
    .t-out { color: #8b949e; }
    .t-hi { color: #58a6ff; }
    .t-yellow { color: #e3b341; }
    .t-green { color: #3fb950; }
    .t-cursor { display: inline-block; width: 8px; height: 14px; background: #3fb950; vertical-align: middle; animation: blink 1s step-end infinite; }
    @keyframes blink { 0%,100% { opacity: 1; } 50% { opacity: 0; } }

    /* ── Section ── */
    section { padding: 80px 24px; max-width: 1100px; margin: 0 auto; }
    .section-label {
      font-size: 13px; font-weight: 700; letter-spacing: .08em;
      text-transform: uppercase; color: var(--green); margin-bottom: 12px;
    }
    .section-title {
      font-size: clamp(1.6rem, 4vw, 2.4rem);
      font-weight: 800; line-height: 1.2; letter-spacing: -.02em;
    }
    .section-title .accent { color: var(--green); }
    .section-sub { margin-top: 12px; color: var(--muted); font-size: 1.05rem; max-width: 540px; }

    /* ── Features grid ── */
    .features { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 16px; margin-top: 48px; }
    .feat-card {
      background: var(--surface); border: 1px solid var(--border);
      border-radius: 12px; padding: 28px; transition: border-color .2s;
    }
    .feat-card:hover { border-color: rgba(63,185,80,.4); }
.feat-title { font-weight: 700; font-size: 16px; margin-bottom: 8px; }
    .feat-desc { font-size: 14px; color: var(--muted); line-height: 1.6; }

    /* ── Lessons list ── */
    .lessons-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 12px; margin-top: 40px; }
    .lesson-pill {
      display: flex; align-items: center; gap: 12px;
      background: var(--surface); border: 1px solid var(--border);
      border-radius: 10px; padding: 14px 16px;
      font-size: 14px; font-weight: 500;
    }
    .lesson-pill .num {
      width: 26px; height: 26px; border-radius: 6px;
      background: var(--green-dim); border: 1px solid rgba(63,185,80,.3);
      display: flex; align-items: center; justify-content: center;
      font-size: 11px; font-weight: 700; color: var(--green); flex-shrink: 0;
    }

    /* ── How it works ── */
    .steps { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 24px; margin-top: 48px; }
    .step { position: relative; }
    .step-num {
      width: 40px; height: 40px; border-radius: 10px;
      background: var(--green-dim); border: 1px solid rgba(63,185,80,.4);
      display: flex; align-items: center; justify-content: center;
      font-weight: 800; font-size: 18px; color: var(--green); margin-bottom: 16px;
    }
    .step h3 { font-weight: 700; font-size: 16px; margin-bottom: 8px; }
    .step p { font-size: 14px; color: var(--muted); line-height: 1.6; }

    /* ── CTA banner ── */
    .cta-banner {
      margin: 0 24px 80px;
      border-radius: 16px;
      background: linear-gradient(135deg, rgba(63,185,80,.12) 0%, rgba(88,166,255,.08) 100%);
      border: 1px solid rgba(63,185,80,.25);
      padding: 60px 40px;
      text-align: center;
      position: relative; overflow: hidden;
    }
    .cta-banner::before {
      content: '';
      position: absolute; top: -50%; left: -20%;
      width: 60%; height: 200%;
      background: radial-gradient(ellipse, rgba(63,185,80,.08) 0%, transparent 70%);
      pointer-events: none;
    }
    .cta-banner h2 { font-size: clamp(1.6rem, 4vw, 2.2rem); font-weight: 800; line-height: 1.2; }
    .cta-banner p { color: var(--muted); margin-top: 12px; font-size: 1rem; }
    .cta-banner .btn-primary { margin-top: 32px; font-size: 17px; padding: 16px 40px; }

    /* ── Footer ── */
    footer {
      border-top: 1px solid var(--border);
      padding: 32px 24px;
      text-align: center;
      color: var(--muted);
      font-size: 13px;
    }
    footer a { color: var(--green); }

    /* ── Divider ── */
    .divider { border: none; border-top: 1px solid var(--border); margin: 0; }

    /* ── Mobile ── */
    @media (max-width: 600px) {
      nav { padding: 0 16px; }
      .hero-stats { gap: 24px; }
      .cta-banner { padding: 40px 20px; margin: 0 12px 60px; }
    }