/* ----------------------------------- */
    /* GLOBAL & STRUCTURE */
    /* ----------------------------------- */
    body {
      font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
      display: flex;
      flex-direction: row; /* Default: controls on left, canvas on right */
      min-height: 100vh;
      margin: 0;
      background-color: #f4f6f8;
    }

    /* Make the layout vertical on small screens (mobile) */
    @media (max-width: 900px) {
      body {
        flex-direction: column;
      }
      #controls {
        width: 100% !important; /* Take full width on mobile */
      }
    }

    /* ----------------------------------- */
    /* CONTROLS PANEL */
    /* ----------------------------------- */
    #controls {
      width: 340px;
      min-width: 300px;
      background-color: #fff;
      border-right: 1px solid #ddd;
      box-shadow: 2px 0 6px rgba(0, 0, 0, 0.05);
      padding: 25px;
      display: flex;
      flex-direction: column;
      justify-content: flex-start;
      overflow-y: auto; /* Allow scrolling if controls are too long */
    }

    h2, h3 {
      margin-top: 15px;
      color: #333;
    }
    
    .matrix-vector-section {
      display: flex;
      align-items: flex-start;
      gap: 25px;
      margin-top: 10px;
    }

    .matrix-container {
      display: inline-grid;
      grid-template-columns: repeat(2, 70px);
      gap: 8px;
      margin-top: 10px;
    }
    
    .vector-container {
      display: flex;
      flex-direction: column;
      align-items: flex-start;
      gap: 8px;
      margin-top: 10px;
    }

    input[type="number"] {
      width: 70px;
      padding: 6px;
      border: 1px solid #ccc;
      border-radius: 5px;
      font-size: 14px;
      text-align: right;
    }

    /* ----------------------------------- */
    /* BUTTONS & INFO */
    /* ----------------------------------- */
    #buttons-container {
      display: flex;
      flex-wrap: wrap; 
      gap: 10px;
      margin-top: 15px;
    }

    button {
      flex: 1;
      padding: 10px 15px;
      border: none;
      color: white;
      font-size: 14px;
      cursor: pointer;
      border-radius: 6px;
      transition: background-color 0.3s;
      min-width: 100px;
    }

    #animate-btn { background-color: #007bff; }
    #animate-btn:hover { background-color: #0056b3; }
    #eigen-btn { background-color: #28a745; }
    #eigen-btn:hover { background-color: #1e7e34; }
    #reset-btn { background-color: #6c757d; }
    #reset-btn:hover { background-color: #5a6268; }
    #full-reset-btn { background-color: #dc3545; }
    #full-reset-btn:hover { background-color: #c82333; }

    #eigen-info {
      background-color: #eef7ff;
      border: 1px solid #b3d9ff;
      padding: 10px;
      border-radius: 5px;
      margin-top: 20px;
      font-size: 0.9em;
      line-height: 1.4;
    }

    /* ----------------------------------- */
    /* CANVAS */
    /* ----------------------------------- */
    #canvas-container {
      flex-grow: 1; /* Allow container to take remaining space */
      display: flex;
      justify-content: center;
      align-items: center;
      padding: 10px;
      min-width: 0; /* Necessary for flex item resizing */
    }

    canvas {
      background-color: #fff;
      max-width: 100%;
      max-height: 100%;
      display: block;
      box-shadow: 0 0 15px rgba(0,0,0,0.1);
    }