← Previous 108 of 112 Next →

Verify node.js existence through command line.

📦 Node.js-> Command Line
✨ The Prompt Phrase
node -v

💻 Code Preview

📦 All-in-One Code
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>⬢ Verify Node.js Existence</title>
  <link href="https://fonts.googleapis.com/css2?family=Poppins:wght@400;600;700;800&family=Fira+Code:wght@400;500&display=swap" rel="stylesheet">
  <style>
    * { margin: 0; padding: 0; box-sizing: border-box; }
    
    :root {
      --node: #68a063;
      --cyan: #06b6d4;
      --purple: #8b5cf6;
      --pink: #ec4899;
      --orange: #f97316;
      --yellow: #fbbf24;
      --blue: #3b82f6;
      --green: #10b981;
      --red: #ef4444;
      --bg: #0a0e1a;
      --card: #151b2e;
      --text: #e2e8f0;
    }

    body {
      font-family: 'Poppins', sans-serif;
      background: var(--bg);
      color: var(--text);
      min-height: 100vh;
      overflow-x: hidden;
    }

    /* Animated background */
    .bg-animation {
      position: fixed;
      inset: 0;
      z-index: -1;
      overflow: hidden;
    }

    .float-node {
      position: absolute;
      font-size: 3rem;
      opacity: 0.08;
      animation: nodeFloat 22s infinite ease-in-out;
    }

    @keyframes nodeFloat {
      0%, 100% { transform: translate(0, 0) rotate(0deg); }
      25% { transform: translate(110px, -90px) rotate(90deg); }
      50% { transform: translate(200px, 70px) rotate(180deg); }
      75% { transform: translate(-80px, 150px) rotate(270deg); }
    }

    .orb {
      position: absolute;
      border-radius: 50%;
      filter: blur(120px);
      opacity: 0.14;
      animation: orbFloat 32s ease-in-out infinite;
    }

    @keyframes orbFloat {
      0%, 100% { transform: translate(0, 0) scale(1); }
      50% { transform: translate(140px, -100px) scale(1.5); }
    }

    /* Progress bar */
    .progress {
      position: fixed;
      top: 0;
      left: 0;
      height: 4px;
      background: linear-gradient(90deg, var(--node), var(--cyan), var(--green));
      z-index: 1000;
      transition: width 0.2s;
    }

    /* Header */
    header {
      text-align: center;
      padding: 70px 20px 50px;
      position: relative;
    }

    .logo-container {
      display: flex;
      justify-content: center;
      align-items: center;
      gap: 28px;
      margin-bottom: 38px;
      flex-wrap: wrap;
    }

    .node-logo {
      width: 130px;
      height: 130px;
      background: linear-gradient(135deg, var(--node), var(--green));
      border-radius: 28px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 4.5rem;
      cursor: pointer;
      transition: all 0.3s;
      box-shadow: 0 22px 65px rgba(104, 160, 99, 0.45);
      animation: logoFloat 4s ease-in-out infinite;
      position: relative;
      overflow: hidden;
    }

    @keyframes logoFloat {
      0%, 100% { transform: translateY(0) rotate(0deg); }
      50% { transform: translateY(-20px) rotate(-6deg); }
    }

    .node-logo::before {
      content: '';
      position: absolute;
      inset: 0;
      background: linear-gradient(45deg, transparent, rgba(255,255,255,0.35), transparent);
      animation: logoShine 3.5s infinite;
    }

    @keyframes logoShine {
      0% { transform: translateX(-100%) rotate(45deg); }
      100% { transform: translateX(200%) rotate(45deg); }
    }

    .node-logo:hover {
      transform: scale(1.18) rotate(12deg);
      box-shadow: 0 35px 90px rgba(104, 160, 99, 0.65);
    }

    .version-badge {
      background: rgba(6, 182, 212, 0.15);
      border: 2px solid var(--cyan);
      border-radius: 16px;
      padding: 14px 28px;
      font-family: 'Fira Code', monospace;
      font-size: 1.05rem;
      animation: versionPulse 3.5s ease-in-out infinite;
      color: var(--cyan);
      font-weight: 600;
    }

    @keyframes versionPulse {
      0%, 100% { box-shadow: 0 0 22px rgba(6, 182, 212, 0.35); transform: scale(1); }
      50% { box-shadow: 0 0 45px rgba(6, 182, 212, 0.65); transform: scale(1.05); }
    }

    h1 {
      font-size: clamp(2.2rem, 6vw, 3.8rem);
      font-weight: 800;
      background: linear-gradient(135deg, var(--node), var(--cyan), var(--green));
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
      background-clip: text;
      margin-bottom: 20px;
      line-height: 1.2;
    }

    .subtitle {
      color: #64748b;
      font-size: 1.25rem;
      max-width: 720px;
      margin: 0 auto;
    }

    /* Main container */
    main {
      max-width: 1150px;
      margin: 0 auto;
      padding: 20px;
    }

    .section {
      margin-bottom: 58px;
      opacity: 0;
      transform: translateY(55px);
      transition: all 0.85s ease-out;
    }

    .section.vis {
      opacity: 1;
      transform: translateY(0);
    }

    .sec-title {
      display: flex;
      align-items: center;
      gap: 20px;
      font-size: 1.75rem;
      font-weight: 700;
      margin-bottom: 24px;
    }

    .sec-icon {
      width: 58px;
      height: 58px;
      border-radius: 17px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.7rem;
      animation: iconBounce 3.2s ease-in-out infinite;
    }

    @keyframes iconBounce {
      0%, 100% { transform: translateY(0) rotate(-4deg); }
      50% { transform: translateY(-10px) rotate(4deg); }
    }

    /* Cards */
    .card {
      background: var(--card);
      border-radius: 24px;
      padding: 34px;
      margin-bottom: 26px;
      border: 1px solid rgba(255,255,255,0.08);
      transition: all 0.35s;
      position: relative;
      overflow: hidden;
    }

    .card::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      right: 0;
      height: 5px;
      background: linear-gradient(90deg, var(--node), var(--cyan), var(--green));
    }

    .card:hover {
      transform: translateY(-10px);
      box-shadow: 0 32px 75px rgba(0,0,0,0.45);
      border-color: var(--node);
    }

    .card h3 {
      color: var(--node);
      margin-bottom: 20px;
      font-size: 1.45rem;
      display: flex;
      align-items: center;
      gap: 14px;
    }

    .card p {
      color: #94a3b8;
      line-height: 1.95;
      margin-bottom: 18px;
    }

    /* Featured card */
    .featured {
      background: linear-gradient(135deg, rgba(104, 160, 99, 0.16), rgba(6, 182, 212, 0.16));
      border: 2px solid var(--node);
    }

    .featured-badge {
      position: absolute;
      top: -15px;
      right: 32px;
      background: linear-gradient(135deg, var(--orange), var(--yellow));
      color: #000;
      padding: 8px 22px;
      border-radius: 24px;
      font-size: 0.78rem;
      font-weight: 700;
      animation: badgeGlow 2.2s ease-in-out infinite;
    }

    @keyframes badgeGlow {
      0%, 100% { box-shadow: 0 0 22px rgba(249, 115, 22, 0.55); }
      50% { box-shadow: 0 0 45px rgba(249, 115, 22, 0.85); }
    }

    /* Code blocks */
    .code-block {
      background: #0a0f1a;
      border-radius: 20px;
      overflow: hidden;
      margin: 24px 0;
      border: 1px solid rgba(255,255,255,0.08);
      box-shadow: 0 18px 50px rgba(0,0,0,0.45);
    }

    .code-header {
      background: rgba(0,0,0,0.45);
      padding: 17px 24px;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }

    .code-dots {
      display: flex;
      gap: 9px;
    }

    .dot {
      width: 14px;
      height: 14px;
      border-radius: 50%;
      cursor: pointer;
      transition: all 0.25s;
    }

    .dot:hover { transform: scale(1.45); }
    .dot.r { background: #ff5f56; }
    .dot.y { background: #ffbd2e; }
    .dot.g { background: #27ca40; }

    .code-lang {
      color: var(--node);
      font-size: 0.95rem;
      font-weight: 600;
      font-family: 'Fira Code', monospace;
    }

    .code-copy {
      background: rgba(255,255,255,0.12);
      border: none;
      padding: 9px 20px;
      border-radius: 9px;
      color: var(--text);
      cursor: pointer;
      font-size: 0.88rem;
      transition: all 0.3s;
      font-weight: 600;
    }

    .code-copy:hover { 
      background: var(--node); 
      transform: translateY(-3px);
      color: #fff;
    }

    .code-copy.copied { background: var(--green); }

    .code-body {
      padding: 26px;
      font-family: 'Fira Code', monospace;
      font-size: 0.95rem;
      line-height: 2.1;
      overflow-x: auto;
    }

    .kw { color: var(--purple); }
    .str { color: var(--yellow); }
    .num { color: var(--orange); }
    .func { color: var(--cyan); }
    .comment { color: #6b7280; font-style: italic; }
    .var { color: var(--pink); }
    .cmd { color: var(--node); font-weight: 600; }

    /* Command cards grid */
    .cmd-grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
      gap: 18px;
      margin: 24px 0;
    }

    .cmd-card {
      background: rgba(255,255,255,0.03);
      padding: 24px;
      border-radius: 16px;
      border: 2px solid rgba(255,255,255,0.08);
      cursor: pointer;
      transition: all 0.35s;
      position: relative;
      overflow: hidden;
    }

    .cmd-card::before {
      content: '';
      position: absolute;
      top: 0;
      left: -100%;
      width: 100%;
      height: 100%;
      background: linear-gradient(90deg, transparent, rgba(104, 160, 99, 0.1), transparent);
      transition: left 0.5s;
    }

    .cmd-card:hover::before {
      left: 100%;
    }

    .cmd-card:hover {
      border-color: var(--node);
      background: rgba(104, 160, 99, 0.12);
      transform: translateY(-6px);
    }

    .cmd-card-icon {
      font-size: 2.8rem;
      margin-bottom: 14px;
      animation: iconFloat 3s ease-in-out infinite;
    }

    @keyframes iconFloat {
      0%, 100% { transform: translateY(0); }
      50% { transform: translateY(-8px); }
    }

    .cmd-card-title {
      color: var(--node);
      font-weight: 600;
      font-size: 1.15rem;
      margin-bottom: 10px;
      font-family: 'Fira Code', monospace;
    }

    .cmd-card-desc {
      color: #64748b;
      font-size: 0.88rem;
      line-height: 1.65;
    }

    /* Info boxes */
    .info {
      padding: 24px;
      border-radius: 18px;
      margin: 22px 0;
      display: flex;
      gap: 18px;
      align-items: flex-start;
    }

    .info.tip {
      background: rgba(16, 185, 129, 0.13);
      border-left: 5px solid var(--green);
    }

    .info.warn {
      background: rgba(251, 191, 36, 0.13);
      border-left: 5px solid var(--yellow);
    }

    .info.important {
      background: rgba(104, 160, 99, 0.13);
      border-left: 5px solid var(--node);
    }

    .info.cool {
      background: rgba(6, 182, 212, 0.13);
      border-left: 5px solid var(--cyan);
    }

    .info-icon { 
      font-size: 1.6rem; 
      flex-shrink: 0;
      animation: iconWiggle 2.5s ease-in-out infinite;
    }

    @keyframes iconWiggle {
      0%, 100% { transform: rotate(0deg); }
      25% { transform: rotate(-10deg); }
      75% { transform: rotate(10deg); }
    }

    /* Interactive terminal */
    .terminal-container {
      background: linear-gradient(135deg, rgba(104, 160, 99, 0.12), rgba(6, 182, 212, 0.12));
      border-radius: 24px;
      padding: 38px;
      border: 2px solid rgba(104, 160, 99, 0.35);
      margin: 30px 0;
    }

    .terminal-title {
      font-size: 1.6rem;
      font-weight: 700;
      color: var(--yellow);
      margin-bottom: 24px;
      text-align: center;
    }

    .terminal {
      background: #0a0f1a;
      border-radius: 18px;
      overflow: hidden;
      margin: 24px 0;
      box-shadow: 0 22px 65px rgba(0,0,0,0.55);
    }

    .term-header {
      background: rgba(0,0,0,0.45);
      padding: 16px 24px;
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .term-title {
      flex: 1;
      text-align: center;
      color: #64748b;
      font-size: 0.95rem;
      font-weight: 600;
    }

    .term-body {
      padding: 26px;
      font-family: 'Fira Code', monospace;
      font-size: 0.95rem;
      min-height: 220px;
      max-height: 520px;
      overflow-y: auto;
    }

    .term-line { 
      margin-bottom: 12px;
      animation: lineAppear 0.35s ease-out;
    }

    @keyframes lineAppear {
      from { opacity: 0; transform: translateX(-12px); }
      to { opacity: 1; transform: translateX(0); }
    }

    .prompt { 
      color: var(--node); 
      font-weight: 600;
      text-shadow: 0 0 12px rgba(104, 160, 99, 0.5);
    }

    .cursor {
      display: inline-block;
      width: 11px;
      height: 22px;
      background: var(--node);
      animation: blink 1.1s infinite;
      vertical-align: middle;
      margin-left: 3px;
    }

    @keyframes blink {
      0%, 50% { opacity: 1; }
      51%, 100% { opacity: 0; }
    }

    /* Buttons */
    .btn-group {
      display: flex;
      gap: 16px;
      justify-content: center;
      flex-wrap: wrap;
      margin: 26px 0;
    }

    .btn {
      background: linear-gradient(135deg, var(--node), var(--green));
      border: none;
      padding: 15px 32px;
      border-radius: 15px;
      color: white;
      font-weight: 700;
      cursor: pointer;
      transition: all 0.35s;
      display: flex;
      align-items: center;
      gap: 12px;
      font-size: 1.05rem;
    }

    .btn:hover {
      transform: translateY(-4px);
      box-shadow: 0 18px 45px rgba(104, 160, 99, 0.55);
    }

    .btn.secondary {
      background: linear-gradient(135deg, var(--cyan), var(--blue));
    }

    .btn.success {
      background: linear-gradient(135deg, var(--green), var(--cyan));
    }

    .btn.purple {
      background: linear-gradient(135deg, var(--purple), var(--pink));
    }

    /* Steps */
    .steps {
      display: flex;
      flex-direction: column;
      gap: 20px;
    }

    .step {
      display: flex;
      gap: 22px;
      padding: 26px;
      background: rgba(255,255,255,0.025);
      border-radius: 18px;
      border: 1px solid rgba(255,255,255,0.07);
      cursor: pointer;
      transition: all 0.35s;
    }

    .step:hover {
      transform: translateX(14px);
      border-color: var(--node);
      background: rgba(104, 160, 99, 0.12);
    }

    .step-num {
      width: 52px;
      height: 52px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--node), var(--green));
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      flex-shrink: 0;
      font-size: 1.3rem;
      box-shadow: 0 10px 28px rgba(104, 160, 99, 0.45);
    }

    .step-content h4 { 
      margin-bottom: 10px; 
      color: var(--text); 
      font-size: 1.15rem;
    }

    .step-content p { 
      color: #64748b; 
      font-size: 0.98rem; 
      margin: 0;
      line-height: 1.7;
    }

    /* Result display */
    .result-box {
      background: rgba(16, 185, 129, 0.12);
      border: 2px solid var(--green);
      border-radius: 18px;
      padding: 26px;
      margin: 22px 0;
      display: none;
    }

    .result-box.show {
      display: block;
      animation: slideDown 0.55s ease-out;
    }

    @keyframes slideDown {
      from { opacity: 0; transform: translateY(-25px); }
      to { opacity: 1; transform: translateY(0); }
    }

    .result-icon {
      font-size: 3.5rem;
      text-align: center;
      margin-bottom: 18px;
      animation: iconPop 0.6s ease-out;
    }

    @keyframes iconPop {
      0% { transform: scale(0); }
      50% { transform: scale(1.2); }
      100% { transform: scale(1); }
    }

    .result-text {
      text-align: center;
      color: var(--green);
      font-weight: 600;
      font-size: 1.15rem;
    }

    /* Comparison table */
    .comparison {
      overflow-x: auto;
      margin: 26px 0;
    }

    .comparison table {
      width: 100%;
      border-collapse: collapse;
      background: var(--card);
      border-radius: 18px;
      overflow: hidden;
    }

    .comparison th {
      background: rgba(104, 160, 99, 0.22);
      padding: 20px;
      text-align: left;
      color: var(--node);
      font-weight: 600;
    }

    .comparison td {
      padding: 20px;
      border-top: 1px solid rgba(255,255,255,0.06);
      color: #94a3b8;
    }

    .comparison tr:hover {
      background: rgba(255,255,255,0.035);
    }

    /* Quiz */
    .quiz {
      background: linear-gradient(135deg, rgba(139, 92, 246, 0.12), rgba(236, 72, 153, 0.12));
      border-radius: 24px;
      padding: 34px;
      border: 2px solid rgba(139, 92, 246, 0.35);
    }

    .quiz-q {
      font-size: 1.3rem;
      font-weight: 600;
      margin-bottom: 26px;
    }

    .quiz-opts {
      display: flex;
      flex-direction: column;
      gap: 16px;
    }

    .quiz-opt {
      padding: 20px 26px;
      background: var(--card);
      border-radius: 16px;
      cursor: pointer;
      transition: all 0.35s;
      border: 2px solid transparent;
      display: flex;
      align-items: center;
      gap: 18px;
    }

    .quiz-opt:hover {
      border-color: var(--purple);
      transform: translateX(12px);
    }

    .quiz-opt.correct {
      border-color: var(--green);
      background: rgba(16, 185, 129, 0.22);
    }

    .quiz-opt.wrong {
      border-color: var(--red);
      background: rgba(239, 68, 68, 0.22);
    }

    .opt-letter {
      width: 38px;
      height: 38px;
      border-radius: 50%;
      background: rgba(255,255,255,0.12);
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
    }

    .quiz-result {
      margin-top: 22px;
      padding: 22px;
      border-radius: 16px;
      text-align: center;
      font-weight: 600;
      display: none;
    }

    .quiz-result.show { 
      display: block; 
      animation: slideUp 0.55s ease-out;
    }

    @keyframes slideUp {
      from { opacity: 0; transform: translateY(25px); }
      to { opacity: 1; transform: translateY(0); }
    }

    /* FAB */
    .fab {
      position: fixed;
      bottom: 32px;
      right: 32px;
      width: 66px;
      height: 66px;
      border-radius: 50%;
      background: linear-gradient(135deg, var(--node), var(--green));
      border: none;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.9rem;
      color: white;
      box-shadow: 0 18px 45px rgba(104, 160, 99, 0.55);
      transition: all 0.35s;
      z-index: 100;
      opacity: 0;
      visibility: hidden;
    }

    .fab.show { opacity: 1; visibility: visible; }
    .fab:hover { transform: scale(1.25) rotate(18deg); }

    /* Toast */
    .toast {
      position: fixed;
      bottom: 130px;
      left: 50%;
      transform: translateX(-50%) translateY(130px);
      background: var(--card);
      padding: 20px 38px;
      border-radius: 18px;
      border: 2px solid var(--node);
      box-shadow: 0 22px 65px rgba(0,0,0,0.65);
      transition: all 0.45s cubic-bezier(0.68, -0.55, 0.265, 1.55);
      z-index: 1000;
      opacity: 0;
      max-width: 90%;
    }

    .toast.show {
      transform: translateX(-50%) translateY(0);
      opacity: 1;
    }

    /* Footer */
    footer {
      text-align: center;
      padding: 52px 20px;
      background: var(--card);
      margin-top: 65px;
      border-top: 1px solid rgba(255,255,255,0.08);
    }

    .footer-icons {
      display: flex;
      justify-content: center;
      gap: 22px;
      margin-bottom: 22px;
    }

    .footer-icon {
      width: 56px;
      height: 56px;
      border-radius: 50%;
      background: rgba(255,255,255,0.08);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 1.7rem;
      cursor: pointer;
      transition: all 0.35s;
    }

    .footer-icon:hover {
      background: var(--node);
      transform: translateY(-10px);
    }

    @media (max-width: 768px) {
      .cmd-grid { grid-template-columns: 1fr; }
      .btn-group { flex-direction: column; }
      .btn { width: 100%; justify-content: center; }
      h1 { font-size: 2.2rem; }
    }
  </style>
</head>
<body>
  <div class="progress" id="progress"></div>
  <div class="bg-animation" id="bgAnim"></div>

  <header>
    <div class="logo-container">
      <div class="node-logo" onclick="celebrate()">⬢</div>
      <div class="version-badge">$ node --version</div>
    </div>
    <h1>Verify Node.js Existence</h1>
    <p class="subtitle">Master the art of checking if Node.js is installed on your system! 🚀</p>
  </header>

  <main>
    <!-- What is Node.js -->
    <section class="section" id="what">
      <div class="sec-title">
        <div class="sec-icon" style="background: linear-gradient(135deg, var(--node), var(--green));">⬢</div>
        <span>What is Node.js?</span>
      </div>

      <div class="card featured">
        <div class="featured-badge">⭐ ESSENTIAL</div>
        <h3>🚀 JavaScript Runtime Environment</h3>
        <p>Node.js is a powerful, open-source JavaScript runtime built on Chrome's V8 engine. It allows you to run JavaScript on your computer and servers, not just in web browsers!</p>

        <div class="info cool">
          <span class="info-icon">✨</span>
          <div>
            <strong>Why Verify Node.js?</strong>
            <p>Before starting any Node.js development, you need to confirm that Node.js is properly installed and accessible from your command line!</p>
          </div>
        </div>
      </div>
    </section>

    <!-- Basic Verification -->
    <section class="section" id="basic">
      <div class="sec-title">
        <div class="sec-icon" style="background: linear-gradient(135deg, var(--cyan), var(--blue));">✅</div>
        <span>Basic Verification Command</span>
      </div>

      <div class="card">
        <h3>🔍 Check Node.js Version</h3>
        <p>The most common way to verify Node.js is installed is to check its version:</p>

        <div class="code-block">
          <div class="code-header">
            <div class="code-dots">
              <div class="dot r"></div>
              <div class="dot y"></div>
              <div class="dot g"></div>
            </div>
            <span class="code-lang">Terminal / Command Prompt</span>
            <button class="code-copy" onclick="copyCode(this, 'node --version')">Copy</button>
          </div>
          <div class="code-body">
            $ <span class="cmd">node</span> --version<br><br>
            <span class="comment">// Output example:</span><br>
            <span style="color: var(--green);">v20.10.0</span>
          </div>
        </div>

        <div class="info tip">
          <span class="info-icon">💡</span>
          <div>
            <strong>What This Means:</strong>
            <p>If you see a version number (like v20.10.0), Node.js is installed! If you see "command not found" or an error, Node.js is not installed.</p>
          </div>
        </div>

        <div class="info important">
          <span class="info-icon">⚡</span>
          <div>
            <strong>Short Version:</strong>
            <p>You can also use the shorthand: <code style="color: var(--node); font-family: 'Fira Code', monospace;">node -v</code></p>
          </div>
        </div>
      </div>
    </section>

    <!-- All Verification Methods -->
    <section class="section" id="methods">
      <div class="sec-title">
        <div class="sec-icon" style="background: linear-gradient(135deg, var(--purple), var(--pink));">🎯</div>
        <span>All Verification Methods</span>
      </div>

      <div class="card">
        <h3>🛠️ Different Ways to Verify</h3>
        <p>Click on each method to learn more:</p>

        <div class="cmd-grid">
          <div class="cmd-card" onclick="showMethod('version')">
            <div class="cmd-card-icon">🔢</div>
            <div class="cmd-card-title">node --version</div>
            <div class="cmd-card-desc">Shows the installed Node.js version number</div>
          </div>
          <div class="cmd-card" onclick="showMethod('which')">
            <div class="cmd-card-icon">📍</div>
            <div class="cmd-card-title">which node</div>
            <div class="cmd-card-desc">Shows Node.js installation path (Mac/Linux)</div>
          </div>
          <div class="cmd-card" onclick="showMethod('where')">
            <div class="cmd-card-icon">📂</div>
            <div class="cmd-card-title">where node</div>
            <div class="cmd-card-desc">Shows Node.js installation path (Windows)</div>
          </div>
          <div class="cmd-card" onclick="showMethod('repl')">
            <div class="cmd-card-icon">💻</div>
            <div class="cmd-card-title">node</div>
            <div class="cmd-card-desc">Starts REPL (confirms Node.js works)</div>
          </div>
          <div class="cmd-card" onclick="showMethod('eval')">
            <div class="cmd-card-icon">⚡</div>
            <div class="cmd-card-title">node -e "code"</div>
            <div class="cmd-card-desc">Execute JavaScript code directly</div>
          </div>
          <div class="cmd-card" onclick="showMethod('help')">
            <div class="cmd-card-icon">❓</div>
            <div class="cmd-card-title">node --help</div>
            <div class="cmd-card-desc">Shows Node.js help and options</div>
          </div>
        </div>
      </div>
    </section>

    <!-- Step by Step -->
    <section class="section" id="steps">
      <div class="sec-title">
        <div class="sec-icon" style="background: linear-gradient(135deg, var(--orange), var(--yellow));">📋</div>
        <span>Step-by-Step Guide</span>
      </div>

      <div class="card">
        <h3>🚶 Follow These Steps</h3>

        <div class="steps">
          <div class="step" onclick="showToast('Step 1: Open your terminal!')">
            <div class="step-num">1</div>
            <div class="step-content">
              <h4>Open Terminal/Command Prompt</h4>
              <p><strong>Windows:</strong> Press <kbd style="background: var(--card); padding: 3px 10px; border-radius: 5px;">Win + R</kbd>, type "cmd", press Enter<br>
              <strong>Mac:</strong> Press <kbd style="background: var(--card); padding: 3px 10px; border-radius: 5px;">Cmd + Space</kbd>, type "Terminal"<br>
              <strong>Linux:</strong> Press <kbd style="background: var(--card); padding: 3px 10px; border-radius: 5px;">Ctrl + Alt + T</kbd></p>
            </div>
          </div>
          <div class="step" onclick="showToast('Step 2: Type the command!')">
            <div class="step-num">2</div>
            <div class="step-content">
              <h4>Type the Verification Command</h4>
              <p>Type: <code style="color: var(--node); font-family: 'Fira Code', monospace;">node --version</code> or <code style="color: var(--node); font-family: 'Fira Code', monospace;">node -v</code></p>
            </div>
          </div>
          <div class="step" onclick="showToast('Step 3: Press Enter!')">
            <div class="step-num">3</div>
            <div class="step-content">
              <h4>Press Enter</h4>
              <p>Execute the command and wait for the result</p>
            </div>
          </div>
          <div class="step" onclick="showToast('Step 4: Check the output!')">
            <div class="step-num">4</div>
            <div class="step-content">
              <h4>Interpret the Output</h4>
              <p>✅ <strong>Version number (e.g., v20.10.0)</strong> = Node.js is installed<br>
              ❌ <strong>Error message</strong> = Node.js is not installed</p>
            </div>
          </div>
        </div>
      </div>
    </section>

    <!-- Interactive Terminal -->
    <section class="section" id="interactive">
      <div class="sec-title">
        <div class="sec-icon" style="background: linear-gradient(135deg, var(--green), var(--cyan));">🎮</div>
        <span>Interactive Terminal</span>
      </div>

      <div class="terminal-container">
        <div class="terminal-title">🎯 Try Node.js Commands!</div>
        <p style="text-align: center; color: #94a3b8; margin-bottom: 22px;">Click buttons to simulate Node.js verification commands</p>

        <div class="terminal">
          <div class="term-header">
            <div class="dot r"></div>
            <div class="dot y"></div>
            <div class="dot g"></div>
            <span class="term-title">Terminal Simulator</span>
          </div>
          <div class="term-body" id="termOutput">
            <div class="term-line">
              <span style="color: #64748b;">Welcome! Click a button below to test Node.js commands</span>
            </div>
            <div class="term-line"><span class="prompt">$</span> <span class="cursor"></span></div>
          </div>
        </div>

        <div class="btn-group">
          <button class="btn" onclick="runCommand('version')">
            🔢 node --version
          </button>
          <button class="btn secondary" onclick="runCommand('eval')">
            ⚡ node -e
          </button>
          <button class="btn success" onclick="runCommand('repl')">
            💻 node (REPL)
          </button>
          <button class="btn purple" onclick="clearTerm()">
            🔄 Clear
          </button>
        </div>

        <div class="result-box" id="resultBox">
          <div class="result-icon">✅</div>
          <div class="result-text">Node.js is installed and working perfectly!</div>
        </div>
      </div>
    </section>

    <!-- Understanding Output -->
    <section class="section" id="output">
      <div class="sec-title">
        <div class="sec-icon" style="background: linear-gradient(135deg, var(--pink), var(--purple));">📊</div>
        <span>Understanding the Output</span>
      </div>

      <div class="card">
        <h3>🔍 What Does the Version Number Mean?</h3>

        <div class="code-block">
          <div class="code-header">
            <div class="code-dots">
              <div class="dot r"></div>
              <div class="dot y"></div>
              <div class="dot g"></div>
            </div>
            <span class="code-lang">Version Format</span>
          </div>
          <div class="code-body">
            <span style="color: var(--green);">v20.10.0</span><br>
            <span style="color: var(--cyan);">│  │  │</span><br>
            <span style="color: var(--cyan);">│  │  └─</span> <span class="comment">Patch version (bug fixes)</span><br>
            <span style="color: var(--cyan);">│  └────</span> <span class="comment">Minor version (new features)</span><br>
            <span style="color: var(--cyan);">└───────</span> <span class="comment">Major version (breaking changes)</span>
          </div>
        </div>

        <div class="info cool">
          <span class="info-icon">📌</span>
          <div>
            <strong>Semantic Versioning:</strong>
            <p>Node.js uses semantic versioning (semver): MAJOR.MINOR.PATCH</p>
          </div>
        </div>

        <div class="comparison">
          <table>
            <thead>
              <tr>
                <th>Version Type</th>
                <th>Example</th>
                <th>Meaning</th>
              </tr>
            </thead>
            <tbody>
              <tr>
                <td>LTS (Long Term Support)</td>
                <td>v20.10.0</td>
                <td>Stable, recommended for production</td>
              </tr>
              <tr>
                <td>Current</td>
                <td>v21.5.0</td>
                <td>Latest features, may be less stable</td>
              </tr>
              <tr>
                <td>Old/Legacy</td>
                <td>v14.x.x</td>
                <td>Outdated, should upgrade</td>
              </tr>
            </tbody>
          </table>
        </div>
      </div>
    </section>

    <!-- Troubleshooting -->
    <section class="section" id="troubleshoot">
      <div class="sec-title">
        <div class="sec-icon" style="background: linear-gradient(135deg, var(--yellow), var(--orange));">🔧</div>
        <span>Troubleshooting</span>
      </div>

      <div class="card">
        <h3>❗ Node.js Not Found?</h3>

        <div class="info warn">
          <span class="info-icon">⚠️</span>
          <div>
            <strong>Command Not Found:</strong>
            <p>If you see "node: command not found" or similar, Node.js is not installed or not in your PATH.</p>
          </div>
        </div>

        <div class="code-block">
          <div class="code-header">
            <div class="code-dots">
              <div class="dot r"></div>
              <div class="dot y"></div>
              <div class="dot g"></div>
            </div>
            <span class="code-lang">Solution: Install Node.js</span>
          </div>
          <div class="code-body">
            <span class="comment">// Download and install Node.js</span><br><br>
            <span style="color: var(--cyan);">1.</span> Visit <span style="color: var(--yellow);">https://nodejs.org</span><br>
            <span style="color: var(--cyan);">2.</span> Download the LTS version (recommended)<br>
            <span style="color: var(--cyan);">3.</span> Run the installer<br>
            <span style="color: var(--cyan);">4.</span> Restart your terminal<br>
            <span style="color: var(--cyan);">5.</span> Try <span class="cmd">node --version</span> again
          </div>
        </div>

        <div class="info tip">
          <span class="info-icon">💡</span>
          <div>
            <strong>Restart Terminal:</strong>
            <p>After installing Node.js, always close and reopen your terminal or command prompt before testing!</p>
          </div>
        </div>
      </div>
    </section>

    <!-- Quick Reference -->
    <section class="section" id="reference">
      <div class="sec-title">
        <div class="sec-icon" style="background: linear-gradient(135deg, var(--cyan), var(--blue));">📚</div>
        <span>Quick Reference</span>
      </div>

      <div class="card">
        <h3>⚡ Common Node.js Verification Commands</h3>

        <div class="code-block">
          <div class="code-header">
            <div class="code-dots">
              <div class="dot r"></div>
              <div class="dot y"></div>
              <div class="dot g"></div>
            </div>
            <span class="code-lang">Cheat Sheet</span>
            <button class="code-copy" onclick="copyCode(this, 'node --version\nnode -v\nwhich node\nwhere node\nnode\nnode -e \"console.log(\'Hello\')\"\nnode --help')">Copy All</button>
          </div>
          <div class="code-body">
            <span class="comment"># Check Node.js version</span><br>
            <span class="cmd">node</span> --version<br>
            <span class="cmd">node</span> -v<br><br>
            <span class="comment"># Find Node.js location (Mac/Linux)</span><br>
            <span class="func">which</span> node<br><br>
            <span class="comment"># Find Node.js location (Windows)</span><br>
            <span class="func">where</span> node<br><br>
            <span class="comment"># Start Node.js REPL</span><br>
            <span class="cmd">node</span><br><br>
            <span class="comment"># Execute JavaScript code</span><br>
            <span class="cmd">node</span> -e <span class="str">"console.log('Hello')"</span><br><br>
            <span class="comment"># Get Node.js help</span><br>
            <span class="cmd">node</span> --help
          </div>
        </div>
      </div>
    </section>

    <!-- Quiz -->
    <section class="section" id="quiz">
      <div class="sec-title">
        <div class="sec-icon" style="background: linear-gradient(135deg, var(--purple), var(--pink));">🧠</div>
        <span>Test Your Knowledge!</span>
      </div>

      <div class="quiz">
        <div class="quiz-q">Which command checks if Node.js is installed?</div>
        <div class="quiz-opts">
          <div class="quiz-opt" onclick="checkQuiz(this, false)">
            <span class="opt-letter">A</span>
            <span>node install</span>
          </div>
          <div class="quiz-opt" onclick="checkQuiz(this, true)">
            <span class="opt-letter">B</span>
            <span>node --version</span>
          </div>
          <div class="quiz-opt" onclick="checkQuiz(this, false)">
            <span class="opt-letter">C</span>
            <span>node start</span>
          </div>
          <div class="quiz-opt" onclick="checkQuiz(this, false)">
            <span class="opt-letter">D</span>
            <span>node check</span>
          </div>
        </div>
        <div class="quiz-result" id="quizResult"></div>
      </div>
    </section>
  </main>

  <button class="fab" id="fab" onclick="scrollTop()">⬆️</button>
  <div class="toast" id="toast"></div>

  <footer>
    <div class="footer-icons">
      <div class="footer-icon">⬢</div>
      <div class="footer-icon">💻</div>
      <div class="footer-icon">🚀</div>
      <div class="footer-icon">✨</div>
    </div>
    <p style="color: #64748b;">Master Node.js Verification! 🎉</p>
    <p style="color: #475569; font-size: 0.88rem; margin-top: 10px;">Always verify before starting your projects!</p>
  </footer>

  <script>
    // Background animation
    const bgAnim = document.getElementById('bgAnim');
    
    // Create floating nodes
    const nodes = ['⬢', '💻', '✅', '🔍', '⚙️', '🚀'];
    for (let i = 0; i < 10; i++) {
      const node = document.createElement('div');
      node.className = 'float-node';
      node.textContent = nodes[Math.floor(Math.random() * nodes.length)];
      node.style.left = Math.random() * 100 + '%';
      node.style.top = Math.random() * 100 + '%';
      node.style.animationDelay = Math.random() * 5 + 's';
      node.style.animationDuration = (Math.random() * 18 + 18) + 's';
      bgAnim.appendChild(node);
    }

    // Create orbs
    const colors = ['var(--node)', 'var(--cyan)', 'var(--green)'];
    for (let i = 0; i < 3; i++) {
      const orb = document.createElement('div');
      orb.className = 'orb';
      orb.style.width = (Math.random() * 420 + 280) + 'px';
      orb.style.height = orb.style.width;
      orb.style.left = Math.random() * 100 + '%';
      orb.style.top = Math.random() * 100 + '%';
      orb.style.background = colors[i];
      orb.style.animationDelay = i * 6 + 's';
      bgAnim.appendChild(orb);
    }

    // Scroll animations
    const sections = document.querySelectorAll('.section');
    const obs = new IntersectionObserver((entries) => {
      entries.forEach(e => {
        if (e.isIntersecting) e.target.classList.add('vis');
      });
    }, { threshold: 0.1 });
    sections.forEach(s => obs.observe(s));

    // Progress bar
    window.addEventListener('scroll', () => {
      const scrolled = (window.scrollY / (document.body.scrollHeight - window.innerHeight)) * 100;
      document.getElementById('progress').style.width = scrolled + '%';
      document.getElementById('fab').classList.toggle('show', window.scrollY > 300);
    });

    // Toast
    function showToast(msg) {
      const toast = document.getElementById('toast');
      toast.textContent = '✨ ' + msg;
      toast.classList.add('show');
      setTimeout(() => toast.classList.remove('show'), 2800);
    }

    // Copy code
    function copyCode(btn, code) {
      navigator.clipboard.writeText(code);
      btn.textContent = 'Copied!';
      btn.classList.add('copied');
      showToast('Code copied to clipboard!');
      setTimeout(() => {
        btn.textContent = 'Copy';
        btn.classList.remove('copied');
      }, 2200);
    }

    // Show method details
    function showMethod(method) {
      const messages = {
        version: 'node --version shows the installed Node.js version number',
        which: 'which node shows the path where Node.js is installed (Mac/Linux)',
        where: 'where node shows the path where Node.js is installed (Windows)',
        repl: 'node starts the REPL (Read-Eval-Print Loop) interactive environment',
        eval: 'node -e allows you to execute JavaScript code directly from command line',
        help: 'node --help displays all available Node.js command-line options'
      };
      showToast(messages[method]);
    }

    // Terminal simulator
    const commands = {
      version: [
        { text: '$ node --version', delay: 350 },
        { text: 'v20.10.0', color: 'var(--green)', delay: 650 }
      ],
      eval: [
        { text: '$ node -e "console.log(\'Hello Node.js!\')"', delay: 350 },
        { text: 'Hello Node.js!', color: 'var(--green)', delay: 700 },
        { text: '', delay: 900 },
        { text: '$ node -e "console.log(2 + 2)"', delay: 1200 },
        { text: '4', color: 'var(--green)', delay: 1500 },
        { text: '', delay: 1700 },
        { text: '✅ Node.js is working!', color: 'var(--green)', delay: 2000 }
      ],
      repl: [
        { text: '$ node', delay: 350 },
        { text: 'Welcome to Node.js v20.10.0.', color: 'var(--cyan)', delay: 700 },
        { text: 'Type ".help" for more information.', color: 'var(--cyan)', delay: 1000 },
        { text: '> console.log("Hello!")', color: '#94a3b8', delay: 1400 },
        { text: 'Hello!', color: 'var(--green)', delay: 1700 },
        { text: 'undefined', color: '#64748b', delay: 1900 },
        { text: '> 5 + 5', color: '#94a3b8', delay: 2300 },
        { text: '10', color: 'var(--green)', delay: 2600 },
        { text: '', delay: 2800 },
        { text: '✅ REPL is working perfectly!', color: 'var(--green)', delay: 3100 }
      ]
    };

    function runCommand(cmd) {
      const output = document.getElementById('termOutput');
      const resultBox = document.getElementById('resultBox');
      output.innerHTML = '';
      resultBox.classList.remove('show');
      
      const scenario = commands[cmd];
      let totalDelay = 0;

      scenario.forEach((line, i) => {
        totalDelay += line.delay;
        setTimeout(() => {
          const div = document.createElement('div');
          div.className = 'term-line';
          div.innerHTML = `<span style="color: ${line.color || '#94a3b8'}">${line.text}</span>`;
          output.appendChild(div);
          output.scrollTop = output.scrollHeight;
          
          if (i === scenario.length - 1) {
            const cursor = document.createElement('div');
            cursor.className = 'term-line';
            cursor.innerHTML = '<span class="prompt">$</span> <span class="cursor"></span>';
            output.appendChild(cursor);
            
            setTimeout(() => {
              resultBox.classList.add('show');
            }, 550);
            
            showToast('Command executed successfully!');
          }
        }, totalDelay);
      });
    }

    function clearTerm() {
      document.getElementById('termOutput').innerHTML = '<div class="term-line"><span style="color: #64748b;">Terminal cleared. Click a button to test commands.</span></div><div class="term-line"><span class="prompt">$</span> <span class="cursor"></span></div>';
      document.getElementById('resultBox').classList.remove('show');
      showToast('Terminal cleared!');
    }

    // Quiz
    function checkQuiz(el, correct) {
      const opts = document.querySelectorAll('.quiz-opt');
      opts.forEach(o => {
        o.style.pointerEvents = 'none';
        o.classList.remove('correct', 'wrong');
      });
      
      el.classList.add(correct ? 'correct' : 'wrong');
      if (!correct) opts[1].classList.add('correct');
      
      const result = document.getElementById('quizResult');
      result.className = 'quiz-result show';
      result.style.background = correct ? 'rgba(16,185,129,0.22)' : 'rgba(239,68,68,0.22)';
      result.innerHTML = correct 
        ? '🎉 Correct! <code style="color: var(--node); font-family: \'Fira Code\', monospace;">node --version</code> (or <code style="color: var(--node); font-family: \'Fira Code\', monospace;">node -v</code>) checks if Node.js is installed!'
        : '❌ Not quite! The correct command is <code style="color: var(--node); font-family: \'Fira Code\', monospace;">node --version</code> or <code style="color: var(--node); font-family: \'Fira Code\', monospace;">node -v</code>';
      
      if (correct) celebrate();
    }

    // Celebrate
    function celebrate() {
      const colors = ['var(--node)', 'var(--green)', 'var(--cyan)', 'var(--yellow)', 'var(--purple)'];
      for (let i = 0; i < 45; i++) {
        const confetti = document.createElement('div');
        confetti.style.position = 'fixed';
        confetti.style.width = '13px';
        confetti.style.height = '13px';
        confetti.style.background = colors[Math.floor(Math.random() * colors.length)];
        confetti.style.left = Math.random() * 100 + '%';
        confetti.style.top = '-35px';
        confetti.style.borderRadius = Math.random() > 0.5 ? '50%' : '0';
        confetti.style.zIndex = '9999';
        confetti.style.pointerEvents = 'none';
        document.body.appendChild(confetti);
        
        const fall = confetti.animate([
          { transform: 'translateY(0) rotate(0deg)', opacity: 1 },
          { transform: `translateY(100vh) rotate(${Math.random() * 720}deg)`, opacity: 0 }
        ], {
          duration: Math.random() * 2700 + 2200,
          easing: 'cubic-bezier(0.25, 0.46, 0.45, 0.94)'
        });
        
        fall.onfinish = () => confetti.remove();
      }
    }

    // Scroll to top
    function scrollTop() {
      window.scrollTo({ top: 0, behavior: 'smooth' });
    }

    // Initial visibility
    setTimeout(() => sections[0].classList.add('vis'), 350);
  </script>
</body>
</html>
Live Preview