<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>GoldenPond</title>
    <style>
        .container {
            max-width: 1600px;
            margin: 0 auto;
            padding: 20px;
        }

        .control-section {
            margin: 20px 0;
        }

        .line-controls-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 20px;
            margin: 20px 0;
        }

        .part-section {
            background: #f5f5f5;