#menuBtn {

            position: fixed;

            top: 20px;
            left: 20px;

            z-index: 20;

            width: auto;
            padding: 12px 18px;

            border: none;
            border-radius: 14px;

            background: rgba(20, 40, 80, 0.85);

            color: #d8ecff;

            font-size: 15px;

            cursor: pointer;

            backdrop-filter: blur(10px);

            border: 1px solid rgba(120, 180, 255, 0.25);

            box-shadow:
                0 0 18px rgba(0, 140, 255, 0.25);

            transition: 0.25s;
        }

        #menuBtn:hover {

            transform: translateY(-2px);

            background: rgba(40, 80, 140, 0.95);

            box-shadow:
                0 0 24px rgba(80, 180, 255, 0.45);
        }
        :root {
            --bg-color: #0d1117;
            --panel-bg: #161b22;
            --border-color: #30363d;
            --text-color: #c9d1d9;
            --accent-a: #58a6ff;
            --accent-b: #ff7b72;
            --neon-green: #3fb950;
        }

        * { box-sizing: border-box; margin: 0; padding: 0; }
        body {
            background-color: var(--bg-color);
            color: var(--text-color);
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
            display: flex;
            flex-direction: column;
            height: 100vh;
            overflow: hidden;
        }

        header {
            background: linear-gradient(90deg, #1f242c, #161b22);
            padding: 12px 20px;
            border-bottom: 1px solid var(--border-color);
            box-shadow: 0 4px 20px rgba(0,0,0,0.5);
            flex-shrink: 0;
        }
        header h1 { font-size: 1.2rem; color: #fff; letter-spacing: 1px; display: flex; align-items: center; gap: 10px;  justify-content: center;}
        header h1::before { content: ''; display: inline-block; width: 6px; height: 20px; background: var(--accent-a); box-shadow: 0 0 8px var(--accent-a); }

        .main-container {
            display: flex;
            flex: 1;
            padding: 20px;
            gap: 20px;
            height: calc(100vh - 50px);
            min-height: 0; /* 允许子元素在垂直方向缩放 */
            flex-direction: row-reverse;
        }

        /* 控制面板 */
        .control-panel {
            width: 320px;
            background-color: var(--panel-bg);
            border: 1px solid var(--border-color);
            border-radius: 8px;
            padding: 15px;
            display: flex;
            flex-direction: column;
            gap: 12px;
            box-shadow: inset 0 0 20px rgba(0,0,0,0.2);
            overflow-y: auto;
            flex-shrink: 0;
        }
        .panel-section {
            border-bottom: 1px solid #21262d;
            padding-bottom: 10px;
        }
        .panel-section:last-child { border: none; }
        .panel-title { font-size: 0.85rem; font-weight: 600; color: #8b949e; margin-bottom: 8px; text-transform: uppercase; letter-spacing: 0.5px; }
        
        .input-group { margin-bottom: 8px; }
        .input-group label { display: block; font-size: 0.8rem; margin-bottom: 4px; color: #8b949e; }
        .input-wrap { display: flex; align-items: center; gap: 10px; }
        input[type="range"] { flex: 1; accent-color: var(--accent-a); background: #21262d; height: 6px; border-radius: 3px; outline: none; }
        input[type="number"] { width: 60px; background: #0d1117; border: 1px solid var(--border-color); color: #fff; padding: 3px 5px; border-radius: 4px; text-align: center; font-family: monospace; font-size: 0.85rem; }

        /* 按钮与选择器 */
        .btn-box { display: flex; gap: 10px; margin-top: auto; padding-top: 10px; }
        button { flex: 1; padding: 10px; border: none; border-radius: 6px; cursor: pointer; font-weight: bold; font-size: 0.85rem; transition: all 0.2s; }
        .btn-run { background: var(--neon-green); color: #000; box-shadow: 0 0 10px rgba(63,185,80,0.3); }
        .btn-run:hover { background: #46c95b; box-shadow: 0 0 15px rgba(63,185,80,0.5); }
        .btn-reset { background: #30363d; color: var(--text-color); border: 1px solid var(--border-color); }
        .btn-reset:hover { background: #3c444d; }
        
        .select-rf { width: 100%; padding: 8px; background: #0d1117; border: 1px solid var(--border-color); color: #fff; border-radius: 6px; outline: none; cursor: pointer; font-size: 0.85rem; }

        /* 视窗布局 */
        .display-area {
            flex: 1;
            display: flex;
            flex-direction: column;
            gap: 20px;
            min-width: 0;
            height: 100%;
        }
        
        /* 比例分配：实景占4份，画图占3份 */
        .top-display {
            flex: 4;
            min-height: 0;
            display: flex;
            position: relative;
        }
        .bottom-display {
            flex: 3;
            background-color: var(--panel-bg);
            border: 1px solid var(--border-color);
            border-radius: 8px;
            padding: 45px 15px 15px 15px; /* 上内边距留出位置给标题 */
            position: relative;
            min-height: 0;
            display: flex;
            flex-direction: column;
        }

        .canvas-container {
            position: relative;
            background-color: var(--panel-bg);
            border: 1px solid var(--border-color);
            border-radius: 8px;
            overflow: hidden;
            box-shadow: 0 4px 10px rgba(0,0,0,0.3);
            display: flex;
            flex-direction: column;
            width: 100%;
            height: 100%;
            padding-top: 45px; /* 上内边距留出位置给标题 */
            min-height: 0;
        }

        /* 绝对定位容器：防止 Canvas 尺寸变化干扰父容器高度计算，彻底打破死循环 */
        .canvas-wrapper {
            position: relative;
            flex: 1;
            width: 100%;
            height: 100%;
            min-height: 0;
        }
        
        #simCanvas, #chartCanvas {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            display: block;
        }
        
        .canvas-title { position: absolute; top: 12px; left: 15px; font-size: 0.8rem; color: #8b949e; z-index: 10; font-weight: 600; text-shadow: 0 2px 4px rgba(0,0,0,0.8); }
        
        /* 数据面板 */
        .hud-overlay {
            position: absolute; top: 12px; right: 15px; font-family: monospace; font-size: 0.8rem; background: rgba(13,17,23,0.85);
            padding: 8px; border-radius: 6px; border: 1px solid var(--border-color); pointer-events: none; display: flex; flex-direction: column; gap: 4px; z-index: 10;
        }
        .hud-a { color: var(--accent-a); }
        .hud-b { color: var(--accent-b); }