:root {
            --base:         #FFFFFF;
            --base-light:   #FAFAFA;
            --base-dark:    #F5F5F5;
            --main:         #1e3a5f;
            --main-light:   #2d5a8f;
            --main-dark:    #0f1e3a;
            --accent:       #d4af37;
            --accent-light: #f4cf5f;
            --accent-dark:  #b8941f;
            --text:         #2C3E50;
            --text-light:   #7F8C8D;
            --border:       #E8E8E8;
            --shadow:       0 4px 20px rgba(30,58,95,0.10);
            --shadow-lg:    0 8px 30px rgba(30,58,95,0.15);
        }
        * { box-sizing: border-box; margin: 0; padding: 0; }

        .nainori-wrap {
            overflow: hidden;
            position: relative;
            width: 100%;
            height: 100vh;
            font-family: 'Helvetica Neue','Hiragino Kaku Gothic ProN','Meiryo',sans-serif;
            background: linear-gradient(135deg, #FFFFFF 0%, #F8F9FA 50%, #F0F2F5 100%);
            color: var(--text);
        }

        /* ========== サイドパネル ========== */
        #ui-panel {
            position: absolute; top: 0; left: 0;
            width: 300px; height: 100vh;
            background: var(--base);
            border-right: 1px solid var(--border);
            box-shadow: 4px 0 20px rgba(30,58,95,0.08);
            display: flex; flex-direction: column;
            z-index: 100;
        }

        .panel-header {
            background: var(--main);
            border-top: 3px solid var(--accent);
            border-bottom: 3px solid var(--accent);
            padding: 14px 16px;
            flex-shrink: 0;
            position: relative;
            overflow: hidden;
        }
        .panel-header::before {
            content: '';
            position: absolute; top: 0; left: -100%;
            width: 200%; height: 100%;
            background: linear-gradient(90deg, transparent, rgba(212,175,55,0.12), transparent);
            animation: shine 4s infinite;
        }
        @keyframes shine { 0%{left:-100%} 100%{left:100%} }

        .panel-header h1 {
            font-size: 13px; font-weight: 900;
            color: #fff; letter-spacing: 0.06em;
            text-shadow: 0 2px 8px rgba(0,0,0,0.25);
            position: relative;
        }
        .panel-header .brand {
            font-size: 10px; color: var(--accent-light);
            letter-spacing: 0.1em; margin-bottom: 2px;
        }

        .panel-scroll {
            flex: 1;
            overflow-y: auto;
            overflow-x: hidden;
            padding: 14px;
            display: flex; flex-direction: column; gap: 12px;
            min-height: 0;
        }
        .panel-scroll::-webkit-scrollbar { width: 5px; }
        .panel-scroll::-webkit-scrollbar-track { background: var(--base-dark); }
        .panel-scroll::-webkit-scrollbar-thumb { background: var(--main-light); border-radius: 3px; }

        /* セクション */
        .section {
            background: var(--base);
            border: 1.5px solid var(--border);
            border-radius: 14px;
            padding: 16px 14px 14px;
            box-shadow: var(--shadow);
            position: relative;
            flex-shrink: 0;
        }
        .section::before {
            content: '';
            position: absolute; top: 0; left: 0; right: 0;
            height: 4px;
            background: linear-gradient(90deg, var(--accent), var(--accent-light), var(--accent));
            border-radius: 14px 14px 0 0;
        }
        .section-title {
            font-size: 10px; font-weight: 900;
            color: var(--main); letter-spacing: 0.1em;
            text-transform: uppercase; margin-bottom: 10px;
            margin-top: 4px;
            display: flex; align-items: center; gap: 6px;
        }
        .section-title::before {
            content: '';
            display: inline-block; width: 4px; height: 14px;
            background: var(--accent); border-radius: 2px;
        }

        /* スライダー */
        .slider-row {
            display: grid; grid-template-columns: 54px 1fr 30px;
            align-items: center; gap: 8px; margin-bottom: 7px;
        }
        .slider-label { font-size: 11px; color: var(--text-light); font-weight: 700; }
        .slider-val {
            font-size: 13px; font-weight: 900;
            color: var(--main); text-align: center;
            background: var(--base-dark); border-radius: 6px;
            padding: 2px 0; border: 1px solid var(--border);
        }
        input[type="range"] {
            -webkit-appearance: none; width: 100%; height: 5px;
            border-radius: 3px; background: var(--base-dark);
            outline: none; border: 1px solid var(--border);
        }
        input[type="range"]::-webkit-slider-thumb {
            -webkit-appearance: none; width: 18px; height: 18px;
            border-radius: 50%;
            background: linear-gradient(135deg, var(--main-light), var(--main));
            cursor: pointer;
            box-shadow: 0 2px 6px rgba(30,58,95,0.3);
            border: 2px solid #fff;
        }

        /* トグルボタン */
        .vis-btn {
            width: 100%; padding: 11px 14px;
            border-radius: 10px;
            font-size: 12px; font-weight: 800; cursor: pointer;
            transition: all 0.2s; border: 1.5px solid var(--border);
            background: var(--base-dark); color: var(--text-light);
            display: flex; align-items: center; justify-content: space-between;
            text-align: left; line-height: 1;
            margin-bottom: 6px;
        }
        .vis-btn .vis-status {
            font-size: 10px; font-weight: 700;
            padding: 3px 8px; border-radius: 20px;
            background: var(--border); color: var(--text-light);
        }
        .vis-btn.on {
            background: linear-gradient(135deg, var(--main-light), var(--main));
            color: #fff; border-color: var(--main);
            box-shadow: 0 3px 10px rgba(30,58,95,0.25);
        }
        .vis-btn.on .vis-status { background: rgba(255,255,255,0.25); color: #fff; }
        .vis-btn.on:hover { transform: translateY(-1px); }
        .vis-btn.accent-on {
            background: linear-gradient(135deg, var(--accent-light), var(--accent));
            color: var(--main-dark); border-color: var(--accent);
            box-shadow: 0 3px 10px rgba(212,175,55,0.3);
        }
        .vis-btn.accent-on .vis-status { background: rgba(255,255,255,0.4); color: var(--main); }
        /* 修正: 明示的なOFF状態スタイル */
        .vis-btn.off {
            background: #ffebee; color: #c62828;
            border-color: #ef9a9a;
        }
        .vis-btn.off .vis-status { background: #fde8e8; color: #c62828; }

        /* 計算結果ボックス */
        #calc-box {
            background: #fff8e1;
            border: 1.5px solid var(--accent);
            border-radius: 10px;
            padding: 12px 14px;
            font-size: 13px;
            line-height: 2;
            position: relative;
        }
        #calc-box .formula-row {
            display: flex; align-items: center; gap: 6px;
            font-size: 13px; color: var(--text);
        }
        #calc-box .result-row {
            border-top: 1.5px solid var(--accent);
            margin-top: 6px; padding-top: 6px;
            display: flex; align-items: center; gap: 6px;
        }
        #calc-box .big-num {
            font-size: 28px; font-weight: 900; line-height: 1;
            color: var(--main);
        }
        #calc-box .unit { font-size: 12px; color: var(--text-light); }

        /* 答えマスク */
        #answer-mask {
            position: absolute; inset: 0; border-radius: 10px;
            background: var(--main);
            display: flex; align-items: center; justify-content: center;
            flex-direction: column; gap: 4px;
            cursor: pointer;
            transition: opacity 0.2s;
        }
        #answer-mask:hover { background: var(--main-light); }
        #answer-mask .mask-text {
            font-size: 12px; font-weight: 800;
            color: var(--accent-light);
        }
        #answer-mask span { font-size: 10px; color: rgba(255,255,255,0.6); }

        /* 凡例 */
        .legend {
            display: flex; flex-wrap: wrap; gap: 6px; margin-top: 4px;
        }
        .legend-item {
            display: flex; align-items: center; gap: 4px;
            font-size: 11px; color: var(--text-light);
        }
        .legend-dot {
            width: 12px; height: 12px; border-radius: 3px; flex-shrink: 0;
        }

        /* 右下ズームパネル */
        #zoom-panel {
            position: absolute; bottom: 20px; right: 20px;
            display: flex; align-items: center; gap: 10px;
            background: var(--base);
            border: 1.5px solid var(--border);
            border-radius: 40px;
            padding: 10px 18px;
            box-shadow: var(--shadow-lg);
            z-index: 200;
            min-width: 220px;
        }
        #zoom-panel input[type="range"] { flex: 1; height: 5px; }
        #zoom-val {
            font-size: 12px; font-weight: 800;
            color: var(--main); min-width: 28px; text-align: center;
            background: var(--base-dark); border-radius: 6px;
            padding: 2px 4px; border: 1px solid var(--border);
        }

        .tip { font-size: 11px; color: var(--text-light); margin-top: 4px; line-height: 1.5; }