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

/* 棕色搭配配色 */
:root {
    --eye-bg-page: #d4c4a8;
    --eye-bg-card: #f5f0e6;
    --eye-bg-cell: #faf8f3;
    --eye-bg-cell-hover: #ede6d9;
    --eye-text: #3e2723;
    --eye-text-muted: #5d4e37;
    --eye-border: #b8a88a;
    --eye-accent: #6d4c41;
    --eye-error-bg: #ffebee;
    --eye-error-text: #b71c1c;
    --eye-highlight: #e8e0d5;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--eye-bg-page);
    color: var(--eye-text);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    background: var(--eye-bg-card);
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 8px 32px rgba(62, 39, 35, 0.12);
    max-width: 800px;
    width: 100%;
}

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

header h1 {
    color: var(--eye-text);
    font-size: 2.5em;
    font-weight: 700;
}

.controls {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    margin-bottom: 20px;
    justify-content: center;
    align-items: center;
}

.control-group {
    display: flex;
    align-items: center;
    gap: 10px;
}

.control-group label {
    font-weight: 600;
    color: var(--eye-text-muted);
}

.control-group select {
    padding: 8px 15px;
    border: 2px solid var(--eye-border);
    border-radius: 8px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s;
    background: var(--eye-bg-cell);
    color: var(--eye-text);
}

.control-group select:hover {
    border-color: var(--eye-accent);
}

.control-group select:focus {
    outline: none;
    border-color: var(--eye-accent);
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.btn-primary {
    background: var(--eye-accent);
    color: #fff;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(109, 76, 65, 0.35);
}

.btn-secondary {
    background: var(--eye-bg-cell-hover);
    color: var(--eye-text-muted);
}

.btn-secondary:hover {
    background: var(--eye-border);
    color: var(--eye-text);
    transform: translateY(-2px);
}

.game-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding: 15px;
    background: var(--eye-bg-cell);
    border-radius: 10px;
    color: var(--eye-text);
}

#timer {
    font-weight: 600;
    color: var(--eye-accent);
    font-size: 1.1em;
}

#message {
    font-weight: 600;
    color: var(--eye-accent);
    min-height: 24px;
}

#message.error {
    color: var(--eye-error-text);
}

#sudoku-container {
    display: flex;
    justify-content: center;
    margin-bottom: 20px;
    width: 100%;
}

#sudoku-grid {
    display: grid;
    gap: 2px;
    background: var(--eye-border);
    border: 2px solid var(--eye-text-muted);
    padding: 2px;
    border-radius: 5px;
    width: 100%;
    max-width: 100%;
}

.cell {
    background: var(--eye-bg-cell);
    border: 1px solid var(--eye-border);
    color: var(--eye-text);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    user-select: none;
    min-width: 40px;
    min-height: 40px;
    aspect-ratio: 1;
}

.cell:hover {
    background: var(--eye-bg-cell-hover);
}

.cell.selected {
    background: var(--eye-highlight);
    border-color: var(--eye-accent);
    color: var(--eye-text);
}

.cell.fixed {
    background: var(--eye-bg-cell-hover);
    color: var(--eye-text);
    font-weight: 700;
    cursor: default;
}

.cell.error {
    background: var(--eye-error-bg);
    color: var(--eye-error-text);
}

.cell.highlight {
    background: var(--eye-highlight);
}

.cell.has-notes {
    padding: 2px;
}

.cell .notes-grid {
    display: grid;
    width: 100%;
    height: 100%;
    gap: 1px;
    padding: 1px;
}

.cell .note-cell {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.35em;
    color: var(--eye-text-muted);
    font-weight: 500;
    min-height: 0;
}

.btn.active {
    background: var(--eye-accent);
    color: #fff;
    box-shadow: 0 2px 8px rgba(109, 76, 65, 0.3);
}

.block-border-top {
    border-top: 2px solid var(--eye-text-muted);
}

.block-border-bottom {
    border-bottom: 2px solid var(--eye-text-muted);
}

.block-border-left {
    border-left: 2px solid var(--eye-text-muted);
}

.block-border-right {
    border-right: 2px solid var(--eye-text-muted);
}

.number-pad {
    display: flex;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
}

.number-btn {
    width: 50px;
    height: 50px;
    border: 2px solid var(--eye-border);
    border-radius: 10px;
    background: var(--eye-bg-cell);
    color: var(--eye-text);
    font-size: 1.2em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.number-btn:hover {
    background: var(--eye-accent);
    color: #fff;
    border-color: var(--eye-accent);
    transform: scale(1.1);
}

.number-btn:active {
    transform: scale(0.95);
}

.number-btn.erase-btn {
    background: #ffebee;
    color: #c62828;
    font-size: 0.9em;
}

.number-btn.erase-btn:hover {
    background: #ffcdd2;
    color: #b71c1c;
    transform: scale(1.1);
}

.number-btn.lock-btn {
    background: #e8e0d5;
    color: #5d4e37;
    font-size: 0.9em;
    transition: all 0.3s;
}

.number-btn.lock-btn:hover {
    background: #d4c4a8;
    transform: scale(1.1);
}

.number-btn.lock-btn.active {
    background: var(--eye-accent);
    color: #fff;
    box-shadow: 0 2px 8px rgba(109, 76, 65, 0.3);
    transform: scale(1.05);
}

.number-btn[data-number].locked {
    background: var(--eye-accent);
    color: #fff;
    box-shadow: 0 2px 8px rgba(109, 76, 65, 0.3);
    transform: scale(1.05);
}

.number-btn.notes-btn {
    background: var(--eye-bg-cell-hover);
    color: var(--eye-text-muted);
    font-size: 0.9em;
}

.number-btn.notes-btn.active {
    background: var(--eye-accent);
    color: #fff;
    box-shadow: 0 2px 8px rgba(109, 76, 65, 0.3);
}

/* 响应式设计 */
@media (max-width: 600px) {
    body {
        padding: 5px;
    }
    
    .container {
        padding: 10px;
        max-width: 100%;
    }
    
    header {
        margin-bottom: 15px;
    }
    
    header h1 {
        font-size: 1.8em;
    }
    
    .controls {
        flex-direction: column;
        gap: 10px;
        margin-bottom: 15px;
    }
    
    .control-group {
        width: 100%;
        justify-content: space-between;
    }
    
    .btn {
        width: 100%;
    }
    
    .game-info {
        padding: 10px;
        margin-bottom: 15px;
    }
    
    #sudoku-container {
        width: 100%;
        padding: 0;
        margin-bottom: 15px;
    }
    
    #sudoku-grid {
        width: 100%;
        max-width: 100%;
        border: 1.5px solid var(--eye-text-muted);
        gap: 0.5px; /* gap从1px改为0.5px */
        padding: 0.5px; /* padding从1px改为0.5px */
    }
    
    .cell {
        min-width: 0;
        width: 100%;
        aspect-ratio: 1;
        font-size: 1.5em; /* 字体从1em增大到1.5em */
        border: 0.3px solid var(--eye-border);
    }
    
    .cell .notes-grid {
        gap: 0.5px;
        padding: 0.5px;
    }
    
    .cell .note-cell {
        font-size: 0.4em;
    }
    
    .block-border-top {
        border-top: 1.5px solid var(--eye-text-muted);
    }
    
    .block-border-bottom {
        border-bottom: 1.5px solid var(--eye-text-muted);
    }
    
    .block-border-left {
        border-left: 1.5px solid var(--eye-text-muted);
    }
    
    .block-border-right {
        border-right: 1.5px solid var(--eye-text-muted);
    }
    
    .number-pad {
        gap: 8px;
        margin-top: 10px;
    }
    
    .number-btn {
        width: 40px;
        height: 40px;
        font-size: 1em;
    }
    
    .number-btn.erase-btn {
        font-size: 0.8em;
    }
    
    .number-btn.lock-btn {
        font-size: 0.8em;
    }
    
    .number-btn.notes-btn {
        font-size: 0.8em;
    }
}