Einstein-de Haas Effect

by Chantal Roth

HTML

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Einstein–de Haas · angular momentum transfer</title>
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <style>
    body { margin: 0; overflow: hidden; background-color: #f0f2f5; font-family: 'Segoe UI', Roboto, sans-serif; }

    #info {
      position: absolute;
      top: 20px;
      left: 20px;
      color: #333;
      background: rgba(255, 255, 255, 0.95);
      padding: 25px;
      border-radius: 12px;
      border: 1px solid #ddd;
      box-shadow: 0 10px 30px rgba(0,0,0,0.1);
      max-width: 370px;
      z-index: 10;
    }

    h1 { margin: 0 0 10px 0; font-size: 1.4em; color: #0056b3; }
    p { font-size: 0.95em; line-height: 1.5em; color: #555; margin-bottom: 8px; }

    .metric-box {
      background: #f4f6f9;
      padding: 12px;
      border-radius: 8px;
      margin-top: 15px;
      border-left: 5px solid #0056b3;
    }
    .metric { display: flex; justify-content: space-between; font-family: monospace; font-size: 1.05em; color: #444; margin-bottom: 4px; }
    .val { font-weight: bold; color: #d63031; }

    #controls {
      position: absolute;
      bottom: 40px;
      width: 100%;
      display: flex;
      justify-content: center;
      gap: 14px;
      pointer-events: auto;
      z-index: 10;
      flex-wrap: wrap;
    }

    button {
      background: white;
      border: 2px solid #0056b3;
      border-radius: 8px;
      padding: 12px 18px;
      color: #0056b3;
      font-weight: bold;
      font-size: 13px;
      text-transform: uppercase;
      cursor: pointer;
      box-shadow: 0 4px 6px rgba(0,0,0,0.05);
      transition: all 0.2s ease;
    }
    button:hover {
      transform: translateY(-2px);
      background: #f8faff;
      box-shadow: 0 6px 12px rgba(0,0,0,0.1);
    }
    button.active {
      background: #0056b3;
      color: white;
      box-shadow: inset 0 2px 4px...