<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, sans-serif;
      color: #1e2945;
      background: #ffffff;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
      user-select: none;
    }

    .header-row {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
      max-width: 580px;
      margin-bottom: 8px;
    }

    .title-tag {
      font-size: 15px;
      font-weight: 700;
      letter-spacing: 0.5px;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .btn-toggle {
      background: #f1f5f9;
      border: 1px solid #cbd5e1;
      color: #1e2945;
      padding: 6px 14px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 600;
      cursor: pointer;
      display: flex;
      align-items: center;
      gap: 6px;
      transition: all 0.2s ease;
    }
    .btn-toggle:hover { background: #e2e8f0; }

    /* RAM Stick Housing */
    .ram-container {
      width: 100%;
      max-width: 580px;
      background: #0f172a;
      border-radius: 8px;
      padding: 10px 10px 4px 10px;
      position: relative;
      box-shadow: 0 4px 12px rgba(15, 23, 42, 0.15);
    }

    .ram-notch {
      position: absolute;
      bottom: -6px;
      left: 45%;
      width: 18px;
      height: 8px;
      background: #ffffff;
      border-radius: 4px 4px 0 0;
      z-index: 2;
    }

    .ram-label {
      color: #94a3b8;
      font-size: 11px;
      font-weight: 700;
      letter-spacing: 1px;
      margin-bottom: 6px;
      display: flex;
      justify-content: space-between;
    }

    .ram-bar {
      display: flex;
      height: 76px;
      border-radius: 6px;
      overflow: hidden;
      background: #334155;
      position: relative;
    }

    .ram-block {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      color: #ffffff;
      font-size: 13px;
      font-weight: 700;
      text-align: center;
      position: relative;
      transition: all 0.5s ease;
    }

    .ram-block span {
      font-size: 11px;
      font-weight: 500;
      opacity: 0.9;
    }

    .os-block {
      width: 25%;
      background: #ef4444;
    }

    .browser-block {
      width: 25%;
      background: #3b82f6;
    }

    .game-block {
      width: 50%;
      background: #10b981;
    }

    .free-block {
      width: 25%;
      background: #94a3b8;
      color: #1e2945;
    }

    /* Protected Boundary Lines */
    .boundary {
      width: 3px;
      height: 100%;
      background: #ffffff;
      position: relative;
      z-index: 10;
      box-shadow: 0 0 4px rgba(0,0,0,0.4);
    }

    .boundary-tag {
      position: absolute;
      top: -18px;
      left: 50%;
      transform: translateX(-50%);
      background: #1e2945;
      color: #f8fafc;
      font-size: 9px;
      font-weight: 700;
      padding: 2px 6px;
      border-radius: 4px;
      white-space: nowrap;
      pointer-events: none;
    }

    /* RAM Gold Pins */
    .pins-row {
      display: flex;
      justify-content: space-between;
      padding: 4px 6px 0 6px;
      gap: 3px;
    }
    .pin {
      flex: 1;
      height: 6px;
      background: #eab308;
      border-radius: 1px;
    }

    /* Middle Connector & Arrow Section */
    .overflow-zone {
      width: 100%;
      max-width: 580px;
      height: 56px;
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .page-arrow {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 12px;
      font-weight: 700;
      color: #6366f1;
      background: #eef2ff;
      border: 1px dashed #6366f1;
      padding: 4px 12px;
      border-radius: 20px;
      transition: all 0.4s ease;
      opacity: 0.2;
      transform: translateY(-4px);
    }

    .page-arrow.active {
      opacity: 1;
      transform: translateY(0);
      background: #e0e7ff;
      box-shadow: 0 2px 8px rgba(99, 102, 241, 0.2);
    }

    /* Virtual Memory / SSD */
    .ssd-container {
      width: 100%;
      max-width: 580px;
      background: #f8fafc;
      border: 2px solid #cbd5e1;
      border-radius: 8px;
      padding: 8px 12px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 12px;
    }

    .ssd-info {
      display: flex;
      flex-direction: column;
      gap: 2px;
    }

    .ssd-title {
      font-size: 13px;
      font-weight: 700;
      color: #1e2945;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .ssd-sub {
      font-size: 11px;
      color: #64748b;
      font-weight: 500;
    }

    .vmem-slot {
      flex: 1;
      max-width: 220px;
      height: 38px;
      background: #e2e8f0;
      border: 1.5px dashed #94a3b8;
      border-radius: 6px;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 12px;
      font-weight: 600;
      color: #64748b;
      transition: all 0.4s ease;
    }

    .vmem-slot.filled {
      background: #3b82f6;
      border: 1.5px solid #2563eb;
      color: #ffffff;
    }
  </style>
</head>
<body>

  <div class="header-row">
    <div class="title-tag">🧠 Physical RAM (8 GB)</div>
    <button class="btn-toggle" id="actionBtn" onclick="toggleSwap()">
      <span id="btnIcon">⚡</span> <span id="btnText">Simulate Heavy Game</span>
    </button>
  </div>

  
  <div class="ram-container">
    <div class="ram-label">
      <span>DDR4 MEMORY</span>
      <span>PROTECTED ADDRESS SPACES</span>
    </div>
    
    <div class="ram-bar">
      
      <div class="ram-block os-block">
        🔒 OS Kernel
        <span>2 GB</span>
      </div>

      <div class="boundary">
        <div class="boundary-tag">Protected Boundary</div>
      </div>

      
      <div class="ram-block browser-block" id="block2">
        <span id="b2Icon" style="font-size:13px; font-weight:700;">🌐 Browser</span>
        <span id="b2Size">2 GB (Active)</span>
      </div>

      <div class="boundary"></div>

      
      <div class="ram-block game-block" id="block3">
        🎮 Game
        <span id="b3Size">4 GB</span>
      </div>

      <div class="boundary" id="bound3"></div>

      
      <div class="ram-block free-block" id="block4" style="display:none;">
        Free
        <span>2 GB</span>
      </div>
    </div>

    
    <div class="pins-row">
      <div class="pin"></div><div class="pin"></div><div class="pin"></div><div class="pin"></div>
      <div class="pin"></div><div class="pin"></div><div class="pin"></div><div class="pin"></div>
      <div class="pin"></div><div class="pin"></div><div class="pin"></div><div class="pin"></div>
      <div class="pin"></div><div class="pin"></div><div class="pin"></div><div class="pin"></div>
      <div class="pin"></div><div class="pin"></div><div class="pin"></div><div class="pin"></div>
    </div>
    <div class="ram-notch"></div>
  </div>

  
  <div class="overflow-zone">
    <div class="page-arrow" id="pageArrow">
      <span>⬇ Inactive Pages Paged Out</span>
    </div>
  </div>

  
  <div class="ssd-container">
    <div class="ssd-info">
      <div class="ssd-title">💾 Secondary Storage (SSD)</div>
      <div class="ssd-sub">Virtual Memory Pagefile</div>
    </div>
    <div class="vmem-slot" id="vmemSlot">
      <span>Empty Pagefile</span>
    </div>
  </div>

  <script>
    let pagedOut = false;

    function toggleSwap() {
      pagedOut = !pagedOut;
      
      const b2 = document.getElementById('block2');
      const b2Icon = document.getElementById('b2Icon');
      const b2Size = document.getElementById('b2Size');
      const b3 = document.getElementById('block3');
      const b3Size = document.getElementById('b3Size');
      const pageArrow = document.getElementById('pageArrow');
      const vmemSlot = document.getElementById('vmemSlot');
      const btnText = document.getElementById('btnText');
      const btnIcon = document.getElementById('btnIcon');

      if (pagedOut) {
        // Game expands to 6GB, Browser pages swap to SSD
        b2.style.width = "0%";
        b2.style.padding = "0";
        b2.style.overflow = "hidden";
        b2.style.opacity = "0";

        b3.style.width = "75%";
        b3Size.textContent = "6 GB (High Load)";

        pageArrow.classList.add('active');
        pageArrow.innerHTML = "<span>⬇ Browser Inactive Pages → Virtual Memory</span>";

        vmemSlot.classList.add('filled');
        vmemSlot.innerHTML = "🌐 Browser Pages (2 GB)";

        btnText.textContent = "Restore Browser";
        btnIcon.textContent = "↺";
      } else {
        // Reset to normal 2GB + 4GB
        b2.style.width = "25%";
        b2.style.padding = "";
        b2.style.overflow = "visible";
        b2.style.opacity = "1";
        b2Icon.textContent = "🌐 Browser";
        b2Size.textContent = "2 GB";

        b3.style.width = "50%";
        b3Size.textContent = "4 GB";

        pageArrow.classList.remove('active');
        pageArrow.innerHTML = "<span>⬇ Inactive Pages Paged Out</span>";

        vmemSlot.classList.remove('filled');
        vmemSlot.innerHTML = "<span>Empty Pagefile</span>";

        btnText.textContent = "Simulate Heavy Game";
        btnIcon.textContent = "⚡";
      }
    }
  </script>
</body>
</html>

Operating Systems: Managing Your Computer

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>OS Roles: Peripheral & File Management</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
      color: #1e2945;
      background: transparent;
      padding: 12px;
      line-height: 1.4;
    }
    .grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 20px;
      width: 100%;
      max-width: 760px;
      margin: 0 auto;
    }
    @media (max-width: 560px) {
      .grid {
        grid-template-columns: 1fr;
        gap: 18px;
      }
    }
    .column {
      display: flex;
      flex-direction: column;
      gap: 10px;
    }
    .col-header {
      font-size: 13px;
      font-weight: 700;
      letter-spacing: 0.04em;
      text-transform: uppercase;
      color: #475569;
      display: flex;
      align-items: center;
      gap: 7px;
      padding-bottom: 4px;
      border-bottom: 2px solid #e2e8f0;
    }
    .col-header svg {
      width: 16px;
      height: 16px;
      flex-shrink: 0;
    }

    /* Left Column: Peripheral Pipeline */
    .pipe-node {
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 9px 12px;
      background: #ffffff;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 8px;
      box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
    }
    .node-title {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 13px;
      font-weight: 600;
      color: #1e2945;
    }
    .node-os {
      border-left: 4px solid #0284c7;
      background: #f0f9ff;
    }
    .node-driver {
      border-left: 4px solid #7c3aed;
      background: #faf5ff;
    }
    .node-hw {
      border-left: 4px solid #475569;
      background: #f8fafc;
    }
    .pipe-arrow {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 2px;
      font-size: 11px;
      font-weight: 600;
      color: #64748b;
      padding: 1px 0;
    }
    .pipe-arrow svg {
      width: 14px;
      height: 14px;
      color: #94a3b8;
    }
    .pipe-code {
      font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
      font-size: 11px;
      background: #e2e8f0;
      color: #0f172a;
      padding: 2px 7px;
      border-radius: 4px;
      font-weight: 500;
      white-space: nowrap;
    }
    .driver-tag {
      font-size: 11px;
      font-weight: 600;
      color: #7c3aed;
      background: #ede9fe;
      padding: 2px 7px;
      border-radius: 4px;
      white-space: nowrap;
    }

    /* Right Column: File System */
    .tree-row {
      display: flex;
      align-items: center;
      justify-content: space-between;
      font-size: 12px;
      font-weight: 600;
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-left: 4px solid #0284c7;
      border-radius: 8px;
      padding: 8px 12px;
      box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
    }
    .tree-path-wrap {
      display: flex;
      align-items: center;
      gap: 6px;
      overflow: hidden;
    }
    .tree-path {
      color: #64748b;
      font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    }
    .tree-file {
      color: #0284c7;
      font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
      font-weight: 700;
    }
    .fat-map {
      display: flex;
      align-items: center;
      justify-content: space-between;
      background: #ecfdf5;
      border: 1px solid #a7f3d0;
      border-left: 4px solid #059669;
      border-radius: 8px;
      padding: 8px 12px;
      font-size: 12px;
      font-weight: 600;
      color: #065f46;
      box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
    }
    .fat-sectors {
      font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
      font-weight: 700;
      color: #047857;
      letter-spacing: 0.02em;
    }
    .physical-view-wrap {
      display: flex;
      flex-direction: column;
      gap: 6px;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 10px;
    }
    .physical-title {
      font-size: 11px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.03em;
      color: #64748b;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    .sector-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 6px;
    }
    .sector {
      aspect-ratio: 1.5;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 12px;
      font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
      font-weight: 700;
      border-radius: 5px;
      border: 1px solid #cbd5e1;
      background: #ffffff;
      color: #475569;
    }
    .sector.allocated {
      background: #059669;
      border-color: #047857;
      color: #ffffff;
      box-shadow: 0 1px 3px rgba(5, 150, 105, 0.3);
    }
    .legend {
      display: flex;
      align-items: center;
      gap: 14px;
      font-size: 11px;
      font-weight: 600;
      color: #64748b;
      padding-top: 2px;
    }
    .legend-item {
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .color-swatch {
      width: 12px;
      height: 12px;
      border-radius: 3px;
      border: 1px solid #94a3b8;
      background: #ffffff;
    }
    .color-swatch.allocated {
      background: #059669;
      border-color: #047857;
    }
  </style>
</head>
<body>

  <div class="grid">
    
    <div class="column">
      <div class="col-header">
        <svg fill="none" stroke="currentColor" stroke-width="2" viewBox="0 0 24 24">
          <path stroke-linecap="round" stroke-linejoin="round" d="M10.325 4.317c.426-1.756 2.924-1.756 3.35 0a1.724 1.724 0 002.573 1.066c1.543-.94 3.31.826 2.37 2.37a1.724 1.724 0 001.065 2.572c1.756.426 1.756 2.924 0 3.35a1.724 1.724 0 00-1.066 2.573c.94 1.543-.826 3.31-2.37 2.37a1.724 1.724 0 00-2.572 1.065c-.426 1.756-2.924 1.756-3.35 0a1.724 1.724 0 00-2.573-1.066c-1.543.94-3.31-.826-2.37-2.37a1.724 1.724 0 00-1.065-2.572c-1.756-.426-1.756-2.924 0-3.35a1.724 1.724 0 001.066-2.573c-.94-1.543.826-3.31 2.37-2.37.996.608 2.296.07 2.572-1.065z"></path>
          <path stroke-linecap="round" stroke-linejoin="round" d="M15 12a3 3 0 11-6 0 3 3 0 016 0z"></path>
        </svg>
        Peripheral Management
      </div>

      
      <div class="pipe-node node-os">
        <div class="node-title">
          <svg width="16" height="16" fill="none" stroke="#0284c7" stroke-width="2" viewBox="0 0 24 24">
            <rect x="2" y="3" width="20" height="14" rx="2"></rect>
            <path d="M8 21h8m-4-4v4"></path>
          </svg>
          <span>OS / App Layer</span>
        </div>
        <span class="pipe-code">PRINT "Notes.docx"</span>
      </div>

      
      <div class="pipe-arrow">
        <svg fill="none" stroke="currentColor" stroke-width="2.5" viewBox="0 0 24 24">
          <path stroke-linecap="round" stroke-linejoin="round" d="M19 14l-7 7m0 0l-7-7m7 7V3"></path>
        </svg>
        <span>Generic High-Level Command</span>
      </div>

      
      <div class="pipe-node node-driver">
        <div class="node-title">
          <svg width="16" height="16" fill="none" stroke="#7c3aed" stroke-width="2" viewBox="0 0 24 24">
            <path d="M4 7v10l8 4 8-4V7L12 3 4 7z"></path>
            <path d="M12 11l4 2-4 2-4-2 4-2z"></path>
          </svg>
          <span>Device Driver</span>
        </div>
        <span class="driver-tag">Translator (PCL / PostScript)</span>
      </div>

      
      <div class="pipe-arrow">
        <svg fill="none" stroke="currentColor" stroke-width="2.5" viewBox="0 0 24 24">
          <path stroke-linecap="round" stroke-linejoin="round" d="M19 14l-7 7m0 0l-7-7m7 7V3"></path>
        </svg>
        <span class="pipe-code">ESC/P2: 0x1B 0x40 0x4A...</span>
      </div>

      
      <div class="pipe-node node-hw">
        <div class="node-title">
          <svg width="16" height="16" fill="none" stroke="#475569" stroke-width="2" viewBox="0 0 24 24">
            <path d="M6 9V2h12v7M6 18H4a2 2 0 01-2-2v-5a2 2 0 012-2h16a2 2 0 012 2v5a2 2 0 01-2 2h-2"></path>
            <rect x="6" y="14" width="12" height="8" rx="1"></rect>
          </svg>
          <span>Hardware (Printer)</span>
        </div>
        <span style="font-size: 11px; font-weight: 600; color: #475569;">Physical Output</span>
      </div>
    </div>

    
    <div class="column">
      <div class="col-header">
        <svg fill="none" stroke="currentColor" stroke-width="2" viewBox="0 0 24 24">
          <path stroke-linecap="round" stroke-linejoin="round" d="M3 7v10a2 2 0 002 2h14a2 2 0 002-2V9a2 2 0 00-2-2h-6l-2-2H5a2 2 0 00-2 2z"></path>
        </svg>
        File Management
      </div>

      
      <div class="tree-row">
        <div class="tree-path-wrap">
          <svg width="15" height="15" fill="none" stroke="#0284c7" stroke-width="2" viewBox="0 0 24 24">
            <path stroke-linecap="round" stroke-linejoin="round" d="M9 12h6m-6 4h6m2 5H7a2 2 0 01-2-2V5a2 2 0 012-2h5.586a1 1 0 01.707.293l5.414 5.414a1 1 0 01.293.707V19a2 2 0 01-2 2z"></path>
          </svg>
          <span class="tree-path">/Documents/CompSci/</span><span class="tree-file">Notes.txt</span>
        </div>
        <span style="font-size: 11px; color: #64748b; font-weight: 600;">Logical</span>
      </div>

      
      <div class="fat-map">
        <span>File System / FAT Mapping</span>
        <span class="fat-sectors">#03 → #07 → #11</span>
      </div>

      
      <div class="physical-view-wrap">
        <div class="physical-title">
          <span>Physical Storage (Sectors)</span>
          <span style="font-weight: 600; color: #059669;">Fragmented Map</span>
        </div>

        <div class="sector-grid">
          <div class="sector">#01</div>
          <div class="sector">#02</div>
          <div class="sector allocated">#03</div>
          <div class="sector">#04</div>
          <div class="sector">#05</div>
          <div class="sector">#06</div>
          <div class="sector allocated">#07</div>
          <div class="sector">#08</div>
          <div class="sector">#09</div>
          <div class="sector">#10</div>
          <div class="sector allocated">#11</div>
          <div class="sector">#12</div>
        </div>

        <div class="legend">
          <div class="legend-item">
            <div class="color-swatch allocated"></div>
            <span>Allocated (#03, #07, #11)</span>
          </div>
          <div class="legend-item">
            <div class="color-swatch"></div>
            <span>Free / Other</span>
          </div>
        </div>
      </div>
    </div>
  </div>

</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      background-color: #f8f9fa;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
      padding: 16px;
    }

    .diagram {
      width: 100%;
      max-width: 480px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 6px;
    }

    .layer {
      width: 100%;
      background: #ffffff;
      border: 1.5px solid #e2e8f0;
      border-radius: 12px;
      padding: 10px 16px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
      transition: box-shadow 0.2s ease;
    }

    .layer.os {
      background-color: #e0f2fe;
      border: 2px solid #0284c7;
      box-shadow: 0 4px 12px rgba(2, 132, 199, 0.12);
    }

    .layer-title {
      font-size: 15px;
      font-weight: 700;
      letter-spacing: -0.01em;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .layer.os .layer-title {
      color: #0369a1;
    }

    .tags {
      display: flex;
      flex-wrap: wrap;
      justify-content: center;
      gap: 6px;
      margin-top: 6px;
    }

    .tag {
      font-size: 12px;
      font-weight: 500;
      background: #f1f5f9;
      color: #334155;
      padding: 3px 8px;
      border-radius: 6px;
      border: 1px solid #e2e8f0;
    }

    .layer.os .tag {
      background: #ffffff;
      color: #0284c7;
      border-color: #bae6fd;
      font-weight: 600;
    }

    .arrow-bridge {
      display: flex;
      align-items: center;
      justify-content: center;
      height: 18px;
      color: #94a3b8;
      font-size: 14px;
      line-height: 1;
      user-select: none;
    }

    .arrow-bridge svg {
      width: 12px;
      height: 18px;
      fill: none;
      stroke: #94a3b8;
      stroke-width: 2;
      stroke-linecap: round;
      stroke-linejoin: round;
    }
  </style>
</head>
<body>

  <div class="diagram">
    
    <div class="layer">
      <div class="layer-title">
        <span>👤</span> User
      </div>
    </div>

    
    <div class="arrow-bridge">
      <svg viewBox="0 0 24 24">
        <path d="M12 3v18M8 7l4-4 4 4M8 17l4 4 4-4"/>
      </svg>
    </div>

    
    <div class="layer">
      <div class="layer-title">Applications</div>
      <div class="tags">
        <span class="tag">🌐 Browser</span>
        <span class="tag">🎮 Game</span>
        <span class="tag">🎵 Music</span>
      </div>
    </div>

    
    <div class="arrow-bridge">
      <svg viewBox="0 0 24 24">
        <path d="M12 3v18M8 7l4-4 4 4M8 17l4 4 4-4"/>
      </svg>
    </div>

    
    <div class="layer os">
      <div class="layer-title">Operating System</div>
      <div class="tags">
        <span class="tag">Kernel</span>
        <span class="tag">Process Scheduler</span>
        <span class="tag">Memory Manager</span>
        <span class="tag">Device Drivers</span>
      </div>
    </div>

    
    <div class="arrow-bridge">
      <svg viewBox="0 0 24 24">
        <path d="M12 3v18M8 7l4-4 4 4M8 17l4 4 4-4"/>
      </svg>
    </div>

    
    <div class="layer">
      <div class="layer-title">Hardware</div>
      <div class="tags">
        <span class="tag">CPU</span>
        <span class="tag">RAM</span>
        <span class="tag">SSD</span>
        <span class="tag">GPU</span>
      </div>
    </div>
  </div>

</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    }

    body {
      padding: 16px;
      background: transparent;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
      user-select: none;
    }

    .main-stage {
      width: 100%;
      max-width: 480px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 16px;
    }

    /* CPU Box */
    .cpu-card {
      width: 100%;
      max-width: 220px;
      background: #ffffff;
      border: 2px solid #e2e8f0;
      border-radius: 12px;
      padding: 12px;
      text-align: center;
      box-shadow: 0 4px 12px rgba(30, 41, 69, 0.05);
      transition: border-color 0.3s ease;
    }

    .cpu-title {
      font-size: 13px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.5px;
      color: #64748b;
      margin-bottom: 6px;
    }

    .cpu-active-task {
      font-size: 16px;
      font-weight: 700;
      padding: 6px 12px;
      border-radius: 6px;
      color: #ffffff;
      transition: background-color 0.3s ease;
    }

    /* Connector line */
    .bus-indicator {
      width: 2px;
      height: 20px;
      background: #cbd5e1;
      position: relative;
    }

    .bus-pulse {
      position: absolute;
      top: 0;
      left: -3px;
      width: 8px;
      height: 8px;
      border-radius: 50%;
      background: #2563eb;
      animation: busFlow 0.8s infinite linear;
    }

    @keyframes busFlow {
      0% { top: 0; opacity: 0; }
      50% { opacity: 1; }
      100% { top: 12px; opacity: 0; }
    }

    /* Timeline Container */
    .timeline-wrap {
      width: 100%;
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 10px;
      padding: 12px 10px;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .timeline-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: 12px;
      font-weight: 600;
      color: #64748b;
      padding: 0 2px;
    }

    .slice-grid {
      display: grid;
      grid-template-columns: repeat(6, 1fr);
      gap: 6px;
      width: 100%;
    }

    .slice {
      border: 2px solid transparent;
      border-radius: 6px;
      padding: 10px 2px;
      text-align: center;
      font-size: 13px;
      font-weight: 700;
      color: #ffffff;
      cursor: pointer;
      transition: transform 0.2s ease, box-shadow 0.2s ease, opacity 0.2s ease;
      opacity: 0.45;
    }

    .slice.active {
      opacity: 1;
      transform: translateY(-2px);
      box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
      border-color: #1e2945;
    }

    .task-game { background: #2563eb; }
    .task-music { background: #059669; }
    .task-dl { background: #7c3aed; }

    /* Footer Info & Controls */
    .control-panel {
      width: 100%;
      max-width: 480px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 8px;
      margin-top: 10px;
    }

    .info-badge {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 8px;
      padding: 6px 12px;
      font-size: 13px;
      font-weight: 700;
      color: #1e2945;
    }

    .btn-group {
      display: flex;
      gap: 6px;
    }

    .btn {
      background: #ffffff;
      border: 1px solid #cbd5e1;
      border-radius: 6px;
      padding: 6px 12px;
      font-size: 13px;
      font-weight: 600;
      color: #1e2945;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .btn:active {
      background: #f1f5f9;
    }
  </style>
</head>
<body>

  <div class="main-stage">
    
    <div class="cpu-card" id="cpuCard">
      <div class="cpu-title">CPU Core</div>
      <div class="cpu-active-task task-game" id="cpuTask">Game</div>
    </div>

    
    <div class="bus-indicator">
      <div class="bus-pulse" id="busPulse"></div>
    </div>

    
    <div class="timeline-wrap">
      <div class="timeline-header">
        <span>0ms</span>
        <span>Round-Robin Timeline</span>
        <span>60ms</span>
      </div>

      <div class="slice-grid">
        <div class="slice task-game active" data-name="Game" data-color="#2563eb">Game</div>
        <div class="slice task-music" data-name="Music" data-color="#059669">Music</div>
        <div class="slice task-dl" data-name="Download" data-color="#7c3aed">DL</div>
        <div class="slice task-game" data-name="Game" data-color="#2563eb">Game</div>
        <div class="slice task-music" data-name="Music" data-color="#059669">Music</div>
        <div class="slice task-dl" data-name="Download" data-color="#7c3aed">DL</div>
      </div>
    </div>
  </div>

  
  <div class="control-panel">
    <div class="info-badge">Time Slice = 10ms</div>
    <div class="btn-group">
      <button class="btn" id="prevBtn" title="Previous">◀</button>
      <button class="btn" id="playBtn" title="Play/Pause">⏸</button>
      <button class="btn" id="nextBtn" title="Next">▶</button>
    </div>
  </div>

  <script>
    const slices = document.querySelectorAll('.slice');
    const cpuTask = document.getElementById('cpuTask');
    const cpuCard = document.getElementById('cpuCard');
    const busPulse = document.getElementById('busPulse');
    const playBtn = document.getElementById('playBtn');
    const prevBtn = document.getElementById('prevBtn');
    const nextBtn = document.getElementById('nextBtn');

    let currentIndex = 0;
    let isPlaying = true;
    let timer = null;

    function setStep(index) {
      currentIndex = (index + slices.length) % slices.length;
      
      slices.forEach((slice, i) => {
        slice.classList.toggle('active', i === currentIndex);
      });

      const activeSlice = slices[currentIndex];
      const taskName = activeSlice.dataset.name;
      const taskColor = activeSlice.dataset.color;

      cpuTask.textContent = taskName;
      cpuTask.style.backgroundColor = taskColor;
      cpuCard.style.borderColor = taskColor;
      busPulse.style.backgroundColor = taskColor;
    }

    function startTimer() {
      if (timer) clearInterval(timer);
      timer = setInterval(() => {
        setStep(currentIndex + 1);
      }, 1000);
    }

    function pause() {
      isPlaying = false;
      clearInterval(timer);
      playBtn.textContent = '▶';
    }

    function play() {
      isPlaying = true;
      startTimer();
      playBtn.textContent = '⏸';
    }

    playBtn.addEventListener('click', () => {
      if (isPlaying) pause();
      else play();
    });

    prevBtn.addEventListener('click', () => {
      pause();
      setStep(currentIndex - 1);
    });

    nextBtn.addEventListener('click', () => {
      pause();
      setStep(currentIndex + 1);
    });

    slices.forEach((slice, i) => {
      slice.addEventListener('click', () => {
        pause();
        setStep(i);
      });
    });

    // Initialize
    setStep(0);
    startTimer();
  </script>
</body>
</html>

CS-9

Aligned learning resources

Related diagrams