body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-color: #f0f0f0;
}

.container {
    text-align: center;
    background-color: white;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

h1 {
    color: #333;
}

.controls {
    margin-bottom: 20px;
}

button, select {
    padding: 10px 15px;
    margin: 0 5px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    background-color: #4CAF50;
    color: white;
}

button:hover {
    background-color: #45a049;
}

#sudoku-grid {
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    grid-template-rows: repeat(9, 1fr);
    gap: 1px;
    width: 450px;
    height: 450px;
    margin: 0 auto;
    background-color: #333;
}

.cell {
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: white;
    font-size: 20px;
    cursor: pointer;
}

.cell.fixed {
    background-color: #f0f0f0;
    font-weight: bold;
}

.cell.selected {
    background-color: #e6f7ff;
}

.cell.error {
    background-color: #ffcccc;
}

.cell:nth-child(3n) {
    border-right: 2px solid #333;
}

.cell:nth-child(n+19):nth-child(-n+27),
.cell:nth-child(n+46):nth-child(-n+54) {
    border-bottom: 2px solid #333;
}

#message {
    margin-top: 20px;
    font-size: 18px;
    font-weight: bold;
    color: #333;
}

.error-count {
    margin-left: 15px;
    color: #666;
    font-weight: bold;
}

/* 添加到文件末尾 */
.vip-message {
    margin-top: 10px;
    color: #9c27b0;
    font-weight: bold;
    display: none;
}

.vip-active {
    background-color: #9c27b0;
}

.vip-button {
    background-color: #9c27b0;
    margin-left: 10px;
}

.vip-button:hover {
    background-color: #7b1fa2;
}