* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Comic Sans MS', 'Arial', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background: white;
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

header {
    text-align: center;
    margin-bottom: 30px;
}

h1 {
    color: #ff6b6b;
    font-size: 2.5em;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

.subtitle {
    color: #4ecdc4;
    font-size: 1.2em;
    font-weight: bold;
}

.game-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding: 15px;
    background: #f8f9fa;
    border-radius: 15px;
    font-size: 1.1em;
    font-weight: bold;
}

.timer {
    color: #ff6b6b;
}

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

.grid-size select,
.difficulty select {
    padding: 8px 15px;
    border: 2px solid #4ecdc4;
    border-radius: 10px;
    font-size: 1em;
    font-weight: bold;
    background: white;
    color: #333;
    cursor: pointer;
}

/* 动态调整数独网格大小 */
#sudoku-grid {
    display: grid;
    gap: 2px;
    background: #333;
    padding: 8px;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
    margin: 0 auto;
}

#sudoku-grid.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

#sudoku-grid.grid-6 {
    grid-template-columns: repeat(6, 1fr);
}

#sudoku-grid.grid-9 {
    grid-template-columns: repeat(9, 1fr);
}

#sudoku-grid.grid-16 {
    grid-template-columns: repeat(16, 1fr);
}

.cell {
    background: white;
    border: none;
    font-size: 1.5em;
    font-weight: bold;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    border-radius: 8px;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* 笔记容器样式 */
.notes-container {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: grid;
    gap: 1px;
    padding: 2px;
    pointer-events: none;
}

.note-number {
    font-size: 0.8em;
    color: #666;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: normal;
    min-height: 0;
    min-width: 0;
}

/* 9宫格笔记布局 */
.grid-9 .notes-container {
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(3, 1fr);
}

/* 6宫格笔记布局 */
.grid-6 .notes-container {
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(2, 1fr);
}

/* 4宫格笔记布局 */
.grid-4 .notes-container {
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: repeat(2, 1fr);
}

/* 16宫格笔记布局 */
.grid-16 .notes-container {
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(4, 1fr);
}

/* 不同宫格大小的单元格尺寸 */
.grid-4 .cell {
    width: 60px;
    height: 60px;
    font-size: 2em;
}

.grid-6 .cell {
    width: 55px;
    height: 55px;
    font-size: 1.8em;
}

.grid-9 .cell {
    width: 50px;
    height: 50px;
    font-size: 1.5em;
}

.grid-16 .cell {
    width: 35px;
    height: 35px;
    font-size: 1.2em;
}

.cell:hover {
    background: #e3f2fd;
    transform: scale(1.05);
}

.cell.selected {
    background: #4ecdc4;
    color: white;
    transform: scale(1.1);
}

.cell.fixed {
    background: #ffd93d;
    color: #333;
    cursor: not-allowed;
}

.cell.error {
    background: #ff6b6b;
    color: white;
    animation: shake 0.5s;
}

.cell.correct {
    background: #51cf66;
    color: white;
    animation: bounce 0.5s;
}

/* 动态宫格边框样式 */
.grid-4 .cell:nth-child(2n) {
    margin-right: 4px;
}

.grid-4 .cell:nth-child(n+5):nth-child(-n+8),
.grid-4 .cell:nth-child(n+13):nth-child(-n+16) {
    margin-bottom: 4px;
}

.grid-6 .cell:nth-child(3n) {
    margin-right: 4px;
}

.grid-6 .cell:nth-child(n+7):nth-child(-n+12),
.grid-6 .cell:nth-child(n+19):nth-child(-n+24) {
    margin-bottom: 4px;
}

.grid-9 .cell:nth-child(3n) {
    margin-right: 4px;
}

.grid-9 .cell:nth-child(n+19):nth-child(-n+27),
.grid-9 .cell:nth-child(n+46):nth-child(-n+54) {
    margin-bottom: 4px;
}

.grid-16 .cell:nth-child(4n) {
    margin-right: 4px;
}

.grid-16 .cell:nth-child(n+17):nth-child(-n+32),
.grid-16 .cell:nth-child(n+49):nth-child(-n+64),
.grid-16 .cell:nth-child(n+81):nth-child(-n+96) {
    margin-bottom: 4px;
}

/* 动态数字按钮布局 */
.number-pad {
    display: grid;
    gap: 10px;
    margin-bottom: 20px;
    justify-content: center;
}

.number-pad.size-4 {
    grid-template-columns: repeat(4, 1fr);
    max-width: 300px;
}

.number-pad.size-6 {
    grid-template-columns: repeat(6, 1fr);
    max-width: 450px;
}

.number-pad.size-9 {
    grid-template-columns: repeat(5, 1fr);
    max-width: 500px;
}

.number-pad.size-16 {
    grid-template-columns: repeat(8, 1fr);
    max-width: 600px;
}

.number-btn {
    padding: 15px;
    font-size: 1.3em;
    font-weight: bold;
    border: none;
    border-radius: 15px;
    cursor: pointer;
    transition: all 0.3s ease;
    background: linear-gradient(45deg, #667eea, #764ba2);
    color: white;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

.number-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.3);
}

.number-btn:active {
    transform: translateY(0);
}

/* 16宫格的数字按钮特殊样式 */
.size-16 .number-btn {
    padding: 12px;
    font-size: 1.1em;
}

.clear-btn {
    background: linear-gradient(45deg, #ff6b6b, #ee5a24);
}

.note-mode-btn {
    background: linear-gradient(45deg, #4ecdc4, #44a08d);
    color: white;
    font-size: 0.9em;
}

.note-mode-btn.active {
    background: linear-gradient(45deg, #ff6b6b, #ee5a24);
    animation: pulse 1s infinite;
}

@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

.action-buttons {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 15px;
}

.action-btn {
    padding: 15px 20px;
    font-size: 1.1em;
    font-weight: bold;
    border: none;
    border-radius: 15px;
    cursor: pointer;
    transition: all 0.3s ease;
    background: linear-gradient(45deg, #4ecdc4, #44a08d);
    color: white;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

.action-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.3);
}

.action-btn:active {
    transform: translateY(0);
}

#new-game-btn {
    background: linear-gradient(45deg, #ff9ff3, #f368e0);
}

#check-btn {
    background: linear-gradient(45deg, #51cf66, #40c057);
}

#hint-btn {
    background: linear-gradient(45deg, #ffd93d, #fcc419);
    color: #333;
}

#solve-btn {
    background: linear-gradient(45deg, #748ffc, #5c7cfa);
}

.message {
    margin-top: 20px;
    padding: 15px;
    border-radius: 10px;
    text-align: center;
    font-size: 1.2em;
    font-weight: bold;
    min-height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.message.success {
    background: #d4edda;
    color: #155724;
    border: 2px solid #c3e6cb;
}

.message.error {
    background: #f8d7da;
    color: #721c24;
    border: 2px solid #f5c6cb;
}

.message.info {
    background: #d1ecf1;
    color: #0c5460;
    border: 2px solid #bee5eb;
}

/* 动画效果 */
@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

@keyframes bounce {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        padding: 20px;
        margin: 10px;
    }
    
    h1 {
        font-size: 2em;
    }
    
    .game-info {
        flex-direction: column;
        gap: 10px;
    }
    
    .game-settings {
        flex-direction: column;
        gap: 10px;
    }
    
    .grid-4 .cell {
        width: 50px;
        height: 50px;
        font-size: 1.6em;
    }
    
    .grid-6 .cell {
        width: 45px;
        height: 45px;
        font-size: 1.4em;
    }
    
    .grid-9 .cell {
        width: 40px;
        height: 40px;
        font-size: 1.2em;
    }
    
    .grid-16 .cell {
        width: 30px;
        height: 30px;
        font-size: 1em;
    }
    
    .number-pad.size-4 {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .number-pad.size-6 {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .number-pad.size-9 {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .number-pad.size-16 {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .action-buttons {
        grid-template-columns: 1fr;
    }
}