@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@300;400;600;800&family=Space+Grotesk:wght@300;500;700&display=swap');

  :root {
    --bg: #0d1117;
    --surface: #161b22;
    --surface2: #1f2937;
    --border: #30363d;
    --green: #3fb950;
    --green-dim: #1a3a24;
    --blue: #58a6ff;
    --yellow: #e3b341;
    --purple: #bc8cff;
    --red: #ff7b72;
    --orange: #ffa657;
    --text: #e6edf3;
    --text-dim: #7d8590;
  }

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

  body {
    background: var(--bg);
    color: var(--text);
    font-family: 'Space Grotesk', sans-serif;
    line-height: 1.6;
    min-height: 100vh;
  }

  .scanlines {
    position: fixed; inset: 0; pointer-events: none; z-index: 100;
    background: repeating-linear-gradient(0deg, transparent, transparent 2px, rgba(0,0,0,0.03) 2px, rgba(0,0,0,0.03) 4px);
  }

  header {
    border-bottom: 1px solid var(--border);
    padding: 2rem 3rem;
    display: flex;
    align-items: center;
    gap: 1.5rem;
    background: linear-gradient(135deg, #0d1117 0%, #161b22 100%);
  }

  .logo {
    font-family: 'JetBrains Mono', monospace;
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--green);
    text-shadow: 0 0 30px rgba(63,185,80,0.4);
    letter-spacing: -2px;
  }

  .logo span { color: var(--text-dim); }

  header h1 {
    font-size: 1rem;
    font-weight: 300;
    color: var(--text-dim);
    border-left: 2px solid var(--border);
    padding-left: 1.5rem;
  }

  header h1 strong { color: var(--text); display: block; font-size: 1.2rem; font-weight: 700; }

  .container { max-width: 1100px; margin: 0 auto; padding: 3rem 2rem; }

  /* Mode indicator */
  .mode-bar {
    display: flex; gap: 0.5rem; margin-bottom: 3rem;
    background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 0.75rem 1rem;
    align-items: center; font-family: 'JetBrains Mono', monospace; font-size: 0.85rem;
  }
  .mode-bar span { color: var(--text-dim); }
  .mode-pill {
    padding: 0.2rem 0.8rem; border-radius: 20px; font-weight: 600; font-size: 0.75rem;
    cursor: pointer; transition: all 0.2s;
  }
  .mode-pill.normal { background: var(--green-dim); color: var(--green); border: 1px solid var(--green); }
  .mode-pill.insert { background: #1a2a3a; color: var(--blue); border: 1px solid var(--blue); }
  .mode-pill.visual { background: #2a1a3a; color: var(--purple); border: 1px solid var(--purple); }
  .mode-pill.command { background: #3a2a1a; color: var(--yellow); border: 1px solid var(--yellow); }

  /* Section */
  .section { margin-bottom: 3rem; }

  .section-title {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.7rem;
    letter-spacing: 3px;
    text-transform: uppercase;
    color: var(--text-dim);
    margin-bottom: 1rem;
    display: flex; align-items: center; gap: 1rem;
  }
  .section-title::after {
    content: ''; flex: 1; height: 1px; background: var(--border);
  }

  .section-header {
    font-size: 1.5rem; font-weight: 700; margin-bottom: 1.5rem;
  }

  /* Cards grid */
  .grid { display: grid; gap: 1rem; }
  .grid-2 { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
  .grid-3 { grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); }

  .card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
    transition: border-color 0.2s, transform 0.2s;
  }
  .card:hover { border-color: var(--green); transform: translateY(-2px); }

  .card-title {
    font-size: 0.8rem; font-weight: 700; letter-spacing: 1px;
    text-transform: uppercase; margin-bottom: 1rem;
    display: flex; align-items: center; gap: 0.5rem;
  }
  .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--green); }
  .dot.blue { background: var(--blue); }
  .dot.yellow { background: var(--yellow); }
  .dot.purple { background: var(--purple); }
  .dot.red { background: var(--red); }
  .dot.orange { background: var(--orange); }

  /* Key-value rows */
  .kv { display: flex; flex-direction: column; gap: 0.5rem; }
  .kv-row {
    display: flex; align-items: center; justify-content: space-between;
    padding: 0.5rem 0.75rem;
    background: var(--bg);
    border-radius: 6px;
    font-size: 0.9rem;
    gap: 1rem;
  }
  .kv-row:hover { background: var(--surface2); }

  kbd {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    font-weight: 600;
    padding: 0.2rem 0.6rem;
    border-radius: 5px;
    border: 1px solid;
    white-space: nowrap;
    flex-shrink: 0;
  }
  kbd.green { color: var(--green); background: var(--green-dim); border-color: var(--green); }
  kbd.blue { color: var(--blue); background: #1a2a3a; border-color: var(--blue); }
  kbd.yellow { color: var(--yellow); background: #3a2a1a; border-color: var(--yellow); }
  kbd.purple { color: var(--purple); background: #2a1a3a; border-color: var(--purple); }
  kbd.red { color: var(--red); background: #3a1a1a; border-color: var(--red); }
  kbd.orange { color: var(--orange); background: #3a2a1a; border-color: var(--orange); }

  .desc { color: var(--text-dim); font-size: 0.85rem; flex: 1; }

  /* Big concept blocks */
  .concept {
    background: var(--surface);
    border: 1px solid var(--border);
    border-left: 4px solid var(--green);
    border-radius: 0 12px 12px 0;
    padding: 1.5rem;
    margin-bottom: 1rem;
  }
  .concept.blue { border-left-color: var(--blue); }
  .concept.yellow { border-left-color: var(--yellow); }
  .concept.purple { border-left-color: var(--purple); }

  .concept-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.7rem; letter-spacing: 2px; text-transform: uppercase;
    color: var(--green); margin-bottom: 0.5rem;
  }
  .concept.blue .concept-label { color: var(--blue); }
  .concept.yellow .concept-label { color: var(--yellow); }
  .concept.purple .concept-label { color: var(--purple); }

  .concept p { color: var(--text-dim); font-size: 0.9rem; }

  /* Terminal demo */
  .terminal {
    background: #010409;
    border: 1px solid var(--border);
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 1rem;
  }
  .term-bar {
    background: var(--surface2);
    padding: 0.6rem 1rem;
    display: flex; align-items: center; gap: 0.5rem;
    border-bottom: 1px solid var(--border);
  }
  .term-dot { width: 12px; height: 12px; border-radius: 50%; }
  .term-dot:nth-child(1) { background: #ff5f57; }
  .term-dot:nth-child(2) { background: #febc2e; }
  .term-dot:nth-child(3) { background: #28c840; }
  .term-bar span { color: var(--text-dim); font-size: 0.8rem; margin-left: 0.5rem; font-family: 'JetBrains Mono', monospace; }
  .term-body {
    padding: 1.5rem; font-family: 'JetBrains Mono', monospace; font-size: 0.85rem;
    line-height: 1.8;
  }
  .term-cmd { color: var(--green); }
  .term-out { color: var(--text-dim); }
  .term-comment { color: #3d5a3e; }
  .cursor {
    display: inline-block; width: 10px; height: 1em;
    background: var(--green); opacity: 0.8;
    animation: blink 1s step-end infinite; vertical-align: text-bottom;
  }
  @keyframes blink { 50% { opacity: 0; } }

  /* Workflow diagram */
  .flow {
    display: flex; align-items: center; gap: 0; flex-wrap: wrap;
    background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 2rem;
    justify-content: center; gap: 0.5rem;
  }
  .flow-node {
    padding: 0.8rem 1.5rem; border-radius: 8px; font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem; font-weight: 600; text-align: center;
  }
  .flow-node.green { background: var(--green-dim); color: var(--green); border: 2px solid var(--green); }
  .flow-node.blue { background: #1a2a3a; color: var(--blue); border: 2px solid var(--blue); }
  .flow-node.purple { background: #2a1a3a; color: var(--purple); border: 2px solid var(--purple); }
  .flow-node.yellow { background: #3a2a1a; color: var(--yellow); border: 2px solid var(--yellow); }
  .flow-node small { display: block; font-weight: 300; font-size: 0.7rem; opacity: 0.7; margin-top: 2px; }
  .flow-arrow { color: var(--text-dim); font-size: 1.5rem; }

  /* Tip box */
  .tip {
    background: #0d2318;
    border: 1px solid var(--green);
    border-radius: 8px;
    padding: 1rem 1.5rem;
    font-size: 0.9rem;
    display: flex; gap: 1rem; align-items: flex-start;
    margin-top: 1rem;
  }
  .tip-icon { font-size: 1.2rem; flex-shrink: 0; }
  .tip p { color: var(--text-dim); }
  .tip strong { color: var(--text); }

  .warn {
    background: #2a1a0a;
    border-color: var(--orange);
  }
  .warn .tip-icon { filter: hue-rotate(30deg); }

  footer {
    border-top: 1px solid var(--border);
    padding: 2rem 3rem;
    text-align: center;
    color: var(--text-dim);
    font-size: 0.85rem;
    font-family: 'JetBrains Mono', monospace;
  }
  footer span { color: var(--green); }