:root {

            --cell-size: 48px;
            --grid-bg: #34495e;
            --cage-border: #666;
        }


        
        /* ==================== 控制栏 ==================== */
        .controls-bar {
            display: flex;
            gap: 10px;
            margin-bottom: 16px;
            flex-wrap: wrap;
            align-items: center;
            justify-content: center;
        }
        
        .btn {
            padding: 10px 18px;
            border: none;
            border-radius: 8px;
            cursor: pointer;
            font-size: 0.9rem;
            font-weight: 600;
            transition: all 0.2s;
            background: var(--primary);
            color: white;
            display: inline-flex;
            align-items: center;
            gap: 6px;
        }
        
        .btn:hover { background: var(--primary-dark); transform: translateY(-1px); }
        .btn.secondary { background: var(--secondary); }
        .btn.secondary:hover { background: #7f8c8d; }
        .btn.danger { background: var(--danger); }
		.btn.warning { background: #f39c12; }
        .btn.success { background: var(--success); }
        
        .select-styled {
            padding: 10px 14px;
            border: 2px solid var(--border);
            border-radius: 8px;
            background: white;
            font-size: 0.9rem;
            cursor: pointer;
        }
        
        /* ==================== 游戏状态栏 ==================== */
        .game-status-bar {
            display: flex;
            justify-content: center;
            align-items: center;
            gap: 24px;
            margin-bottom: 16px;
            flex-wrap: wrap;
        }
        
        .timer-box {
            display: flex;
            align-items: center;
            gap: 8px;
            background: var(--card);
            padding: 10px 20px;
            border-radius: var(--radius);
            box-shadow: var(--shadow);
        }
        
        .timer-display {
            font-size: 1.8rem;
            font-weight: 700;
            font-variant-numeric: tabular-nums;
        }
        
        .action-btns-row {
            display: flex;
            gap: 8px;
            flex-wrap: wrap;
            justify-content: center;
        }
        
        .action-btns-row .btn {
            padding: 8px 14px;
            font-size: 0.85rem;
        }
        
        /* ==================== 杀手数独网格（核心样式） ==================== */
        .grid-wrapper {
            display: flex;
            justify-content: center;
            margin-bottom: 20px;
        }
        
        .killer-grid {
            display: grid;
            grid-template-columns: repeat(9, var(--cell-size));
            grid-template-rows: repeat(9, var(--cell-size));
            gap: 0;
            background: var(--grid-bg);
            padding: 2px;
            border: 2px solid var(--grid-bg);
            border-radius: 4px;
            position: relative;
        }
        
        .killer-cell {
            background: white;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.3rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.15s;
            position: relative;
            user-select: none;
            border: 0.5px solid #ddd;
        }
        
        .killer-cell:hover { background: #ecf0f1; }
        /*.killer-cell.selected { background: var(--primary); color: white; }移动到下面了*/
        .killer-cell.fixed { background: #ecf0f1; font-weight: 700; }
        .killer-cell.error { background: #ffeaea; color: var(--danger); animation: shake 0.4s; }
        .killer-cell.highlight { background: #d5e8ff; }
        .killer-cell.same-number { background: #fff3cd; }
        .killer-cell.cage-error { 
            background: #ffeaea; 
            box-shadow: inset 0 0 0 2px var(--danger);
        }
        .killer-cell.cage-complete {
            background: #d4edda;
        }
        
        /* 3x3 宫格粗边框 */
        .killer-cell:nth-child(3n):not(:nth-child(9n)) { border-right: 2px solid var(--grid-bg); }
        .killer-cell:nth-child(n+19):nth-child(-n+27),
        .killer-cell:nth-child(n+46):nth-child(-n+54) { border-bottom: 2px solid var(--grid-bg); }
        
        /* Cage 边框 - 虚线 */
        .cage-border-top { border-top: 2px dashed var(--cage-border) !important; }
        .cage-border-bottom { border-bottom: 2px dashed var(--cage-border) !important; }
        .cage-border-left { border-left: 2px dashed var(--cage-border) !important; }
        .cage-border-right { border-right: 2px dashed var(--cage-border) !important; }
        
        /* Cage 和值标签 */
        .cage-sum-label {
            position: absolute;
            top: 1px;
            left: 2px;
            font-size: 0.6rem;
            font-weight: 700;
            color: var(--cage-border);
            line-height: 1;
            z-index: 5;
            pointer-events: none;
        }
        
        @keyframes shake {
            0%, 100% { transform: translateX(0); }
            25% { transform: translateX(-4px); }
            75% { transform: translateX(4px); }
        }
        
        /* ==================== 数字键盘 ==================== */
        .number-pad-section {
            display: flex;
            flex-direction: column;
            align-items: center;
            margin-bottom: 30px;
        }
        
        .number-pad-label {
            font-size: 0.9rem;
            color: var(--text-light);
            margin-bottom: 12px;
            font-weight: 600;
        }
        
        .number-pad {
            display: grid;
            grid-template-columns: repeat(9, 1fr);
            gap: 8px;
            max-width: 500px;
            width: 100%;
        }
        
        .num-btn {
            aspect-ratio: 1;
            border: 2px solid var(--border);
            background: white;
            border-radius: 10px;
            font-size: 1.4rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.2s;
            color: var(--text);
            display: flex;
            align-items: center;
            justify-content: center;
        }
        
        .num-btn:hover { 
            background: var(--primary); 
            color: white; 
            border-color: var(--primary); 
            transform: scale(1.08);
        }
        
        /* ==================== Cage 信息面板 ==================== */
        .cage-info-panel {
            background: var(--card);
            padding: 20px;
            border-radius: var(--radius);
            box-shadow: var(--shadow);
            margin-bottom: 20px;
        }
        
        .cage-info-panel h3 {
            font-size: 1rem;
            margin-bottom: 12px;
            color: var(--text);
        }
        
        .cage-list {
            display: flex;
            flex-wrap: wrap;
            gap: 8px;
        }
        
        .cage-tag {
            padding: 4px 10px;
            background: var(--bg);
            border-radius: 16px;
            font-size: 0.8rem;
            font-weight: 600;
            color: var(--text-light);
            border: 1px solid var(--border);
        }
        
        .cage-tag.complete {
            background: #d4edda;
            color: #155724;
            border-color: #c3e6cb;
        }
        
        .cage-tag.error {
            background: #f8d7da;
            color: #721c24;
            border-color: #f5c6cb;
        }
        
        /* ==================== 介绍区 ==================== */
        .intro-section {
            background: var(--card);
            padding: 30px;
            border-radius: var(--radius);
            box-shadow: var(--shadow);
            margin-bottom: 30px;
        }
        
        .intro-section h2 {
            font-size: 1.3rem;
            margin-bottom: 16px;
        }
        
        .intro-section p {
            color: var(--text-light);
            line-height: 1.8;
            margin-bottom: 12px;
        }
        
.killer-cell.selected { background: var(--primary); color: white; }
        
        /* ==================== 响应式 ==================== */
        @media (max-width: 768px) {
            :root { --cell-size: 38px; }
            
            .page-header h1 { font-size: 1.5rem; }
            .number-pad { grid-template-columns: repeat(5, 1fr); max-width: 350px; }
        }
        
        @media (max-width: 480px) {
            :root { --cell-size: 34px; }
            
            .cage-sum-label { font-size: 0.5rem; }
            .num-btn { font-size: 1.2rem; }
        }
        
        @media (prefers-color-scheme: dark) {
            :root {
                --bg: #1a1a2e;
                --card: #16213e;
                --text: #e94560;
                --text-light: #a0a0a0;
                --border: #0f3460;
                --grid-bg: #0f3460;
                --cage-border: #888;
            }
            
            .killer-cell { background: #1a1a2e; color: #eee; }
            .killer-cell.fixed { background: #0f3460; color: white; }
            .num-btn { background: #1a1a2e; color: #eee; border-color: #0f3460; }
        }