/* ==================== 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:active { transform: translateY(0); }
        .btn.secondary { background: var(--secondary); }
        .btn.secondary:hover { background: #7f8c8d; }
        .btn.warning { background: #f39c12; }
        .btn.warning:hover { background: #e67e22; }
        .btn.success { background: var(--success); }
        .btn.success:hover { background: #27ae60; }
        
        .select-styled {
            padding: 10px 14px;
            border: 2px solid var(--border);
            border-radius: 8px;
            background: white;
            font-size: 0.9rem;
            cursor: pointer;
            min-width: 110px;
        }
        
        /* ==================== 游戏状态栏（宫格上方） ==================== */
        .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;
            color: var(--text);
            font-variant-numeric: tabular-nums;
            letter-spacing: 1px;
        }
        
        .action-btns-row {
            display: flex;
            gap: 8px;
            flex-wrap: wrap;
            justify-content: center;
        }
        
        .action-btns-row .btn {
            padding: 8px 14px;
            font-size: 0.85rem;
        }
        
        /* ==================== 数独网格 ==================== */
        .grid-wrapper {
            display: flex;
            justify-content: center;
            margin-bottom: 20px;
        }
        
        .sudoku-grid {
            display: grid;
            grid-template-columns: repeat(9, var(--cell-size));
            grid-template-rows: repeat(9, var(--cell-size));
            gap: var(--grid-gap);
            background: var(--grid-bg);
            padding: 2px;
            border: 2px solid var(--grid-bg);
            border-radius: 4px;
        }
        
        .cell {
            background: white;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.4rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.15s;
            position: relative;
            user-select: none;
            -webkit-tap-highlight-color: transparent;
        }
        
        .cell:hover { background: #ecf0f1; }
        .cell.fixed { 
            background: #ecf0f1; 
            color: var(--text); 
            font-weight: 700; 
        }
        .cell.error { 
            background: #ffeaea; 
            color: var(--danger); 
            animation: shake 0.4s; 
        }
        .cell.highlight { background: #d5e8ff; }
        .cell.same-number { background: #fff3cd; }
        .cell.hint { background: #d4edda; }
        
        .cell.selected { background: var(--primary); color: white; }
        .cell:nth-child(3n):not(:nth-child(9n)) { border-right: 2px solid var(--grid-bg); }
        .cell:nth-child(n+19):nth-child(-n+27),
        .cell:nth-child(n+46):nth-child(-n+54) { border-bottom: 2px solid var(--grid-bg); }
        
        @keyframes shake {
            0%, 100% { transform: translateX(0); }
            25% { transform: translateX(-4px); }
            75% { transform: translateX(4px); }
        }
        
        .candidates {
            position: absolute;
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            width: 100%;
            height: 100%;
            font-size: 0.55rem;
            color: var(--text-light);
            padding: 2px;
        }
        .cell.selected span{color:white;}
        .candidates span {
            display: flex;
            align-items: center;
            justify-content: center;
        }
        
        /* ==================== 数字键盘（宫格下方） ==================== */
        .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;
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        }
        
        .num-btn:hover { 
            background: var(--primary); 
            color: white; 
            border-color: var(--primary); 
            transform: scale(1.08); 
            box-shadow: 0 4px 12px rgba(52, 152, 219, 0.3);
        }
        
        .num-btn:active { transform: scale(0.95); }
        
        /* ==================== 数独介绍区 ==================== */
        .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;
            color: var(--text);
            display: flex;
            align-items: center;
            gap: 8px;
        }
        
        .intro-section p {
            color: var(--text-light);
            line-height: 1.8;
            margin-bottom: 12px;
        }
        
        .intro-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 20px;
            margin-top: 20px;
        }
        
        .intro-card {
            background: var(--bg);
            padding: 20px;
            border-radius: 10px;
            border-left: 4px solid var(--primary);
        }
        
        .intro-card h3 {
            font-size: 1rem;
            margin-bottom: 8px;
            color: var(--text);
        }
        
        .intro-card p {
            font-size: 0.9rem;
            color: var(--text-light);
            line-height: 1.6;
            margin: 0;
        }
     
        /* ==================== 响应式设计 ==================== */
        @media (max-width: 768px) {

            
            .controls-bar {
                padding: 0;
                gap: 6px;
            }
            
            .btn { padding: 8px 14px; font-size: 0.85rem; }
            
            .game-status-bar {
                gap: 12px;
            }
            
            .timer-display { font-size: 1.4rem; }
            
            .number-pad {
                grid-template-columns: repeat(5, 1fr);
                max-width: 350px;
            }
            
            .num-btn { font-size: 1.2rem; }
            
            .intro-section { padding: 20px; }
            .intro-grid { grid-template-columns: 1fr; }
        }
        
        @media (max-width: 480px) {

			.candidates {
				font-size: 0.50rem;
				padding: 0px;
			}
            .number-pad {
                grid-template-columns: repeat(5, 1fr);
                gap: 6px;
            }
            
            .timer-box {
                padding: 8px 14px;
            }
            
            .action-btns-row .btn {
                padding: 6px 10px;
                font-size: 0.8rem;
            }
            

        }
        
        @media (prefers-color-scheme: dark) {
            
            .cell { background: #1a1a2e; color: #eee; }
            .cell.fixed { background: #0f3460; color: white; }
            .cell:hover { background: #1a1a2e; filter: brightness(1.2); }
            .num-btn { background: #1a1a2e; color: #eee; border-color: #0f3460; }
        }