/* 1. 전체 레이아웃 및 배경 스타일 */
        body {
            background: radial-gradient(circle, #e0e0e0, #cfcfcf);
            display: flex;
            justify-content: center;
            align-items: center;
            height: 100vh;
            margin: 0;
            font-family: 'Arial', sans-serif;
            overflow: hidden;
        }

        .game-container {
            display: flex;
            gap: 20px;
            align-items: center;
        }

        /* 2. 공통 패널 스타일 (메탈 프레임 느낌) */
        .panel {
            background: #222;
            border: 5px solid #dcdcdc; /* 은색 테두리 */
            border-radius: 15px;
            box-shadow: 
                0 0 0 4px #aaa, /* 2중 테두리 효과 */
                5px 5px 15px rgba(0,0,0,0.5), /* 그림자 */
                inset 2px 2px 5px rgba(255,255,255,0.2); /* 내부 광택 */
            padding: 10px;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
        }
        
        /* 3. 사이드 패널 (Hold, Next, Score) */
        .side-panel {
            width: 100px;
            height: 120px;
            margin-bottom: 20px;
            position: relative;
        }

        .side-panel h3 {
            color: #fff;
            margin: 0 0 10px 0;
            font-size: 14px;
            text-shadow: 1px 1px 2px black;
        }

        .score-box {
            height: 180px;
            justify-content: space-around;
        }

        .score-text {
            color: #fff;
            font-size: 18px;
            font-weight: bold;
            background: #000;
            width: 80%;
            text-align: center;
            padding: 5px 0;
            border-radius: 5px;
            border: 1px solid #444;
        }

        .label {
            color: #ccc;
            font-size: 12px;
            margin-bottom: -5px;
        }

        /* 4. 메인 게임 보드 */
        .board-wrapper {
            width: 250px; /* 25px * 10칸 */
            height: 500px; /* 25px * 20칸 */
            background-color: #000;
            position: relative;
            display: grid;
            grid-template-rows: repeat(20, 25px);
            grid-template-columns: repeat(10, 25px);
            /* 격자 무늬 */
            background-image: 
                linear-gradient(#333 1px, transparent 1px),
                linear-gradient(90deg, #333 1px, transparent 1px);
            background-size: 25px 25px;
        }

        /* 5. 블록 디자인 (CSS로 광택 효과 구현) */
        .block {
            width: 25px;
            height: 25px;
            box-sizing: border-box;
            border: 1px solid rgba(0,0,0,0.2);
            /* 젤리 같은 입체감 효과 */
            box-shadow: 
                inset 3px 3px 5px rgba(255,255,255,0.6), 
                inset -3px -3px 5px rgba(0,0,0,0.4);
            border-radius: 4px;
        }

        /* 고스트 블록 (그림자) */
        .ghost {
            background-color: transparent !important;
            border: 2px solid rgba(255, 255, 255, 0.4);
            box-shadow: none;
        }

        /* 블록 색상 정의 */
        .cyan { background: linear-gradient(135deg, #00ffff, #00aaaa); }
        .blue { background: linear-gradient(135deg, #0055ff, #0000aa); }
        .orange { background: linear-gradient(135deg, #ffaa00, #aa5500); }
        .yellow { background: linear-gradient(135deg, #ffff00, #aaaa00); }
        .green { background: linear-gradient(135deg, #00ff00, #00aa00); }
        .purple { background: linear-gradient(135deg, #aa00ff, #5500aa); }
        .red { background: linear-gradient(135deg, #ff0000, #aa0000); }
        .grey { background: #555; } /* 벽이나 죽은 블록 */

        /* 미니 그리드 (Next, Hold 용) */
        .mini-grid {
            display: grid;
            grid-template-rows: repeat(4, 20px);
            grid-template-columns: repeat(4, 20px);
            gap: 1px;
        }
        .mini-grid .block {
            width: 20px;
            height: 20px;
        }