Reports

So I've created the desired answer for your problem, also here is the snippet:

    document.addEventListener('DOMContentLoaded', () => {
      const formSection = document.getElementById('overflow');
      const textarea = formSection.querySelector('textarea');

      const checkOverflow = () => {
        const hasOverflow = formSection.scrollHeight > formSection.clientHeight;
        formSection.classList.toggle('overflowing', hasOverflow);
      };

      textarea.addEventListener('input', checkOverflow);
      checkOverflow(); // Initial check
    });

    div {
      border: 1px solid #CCC;
      background-color: #FFF;
      margin-bottom: 1rem;
      padding: 1rem;
      width: 8.5in;
      max-height: 7in;
    }

    .static-section {
      display: grid;
      overflow: hidden;
      max-height: 3in;
      width: 7.5in;
    }

    .static-section * {
      margin-top: 0.5rem;
      margin-bottom: 0.5rem;
      padding: 0.5rem;
    }

    .static-section.overflowing {
      background-color: #ffcccc !important; /* Red background for overflow */
    }

    textarea {
      field-sizing: content;
      width: 100%;
      box-sizing: border-box;
    }

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Overflow Detection Example</title>
</head>
<body>
  <form id="entry">
    <section id="top">
      <h1>HEADER</h1>
    </section>

    <section id="middle">
      <div id="overflow" class="static-section">
        <label>This section is locked at a max 3 inches. I want the background color to be red if anything makes this section overflow.</label>
        <textarea placeholder="Type in this section until the following paragraph starts to go off the screen. This is when I want the background color to change."></textarea>
        <p>When this information starts to go off the screen (i.e., enabling overflow - which the scrollbars are being hidden by the static-section class), I want the background color of this div to change. This will provide a visual indication that the provided response is too long.</p>
      </div>
    </section>

    <section id="footer">
      <h1>FOOTER</h1>
    </section>
  </form>
</body>
</html>

This will create the background red when the paragraph overflows.

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