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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #0a0e27 0%, #1a237e 50%, #0d47a1 100%);
    color: #e0e0ff;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
    position: relative;
    overflow-x: hidden;
}

/* 背景光效 */
body::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 10% 20%, rgba(124, 77, 255, 0.15) 0%, transparent 25%),
        radial-gradient(circle at 90% 80%, rgba(33, 150, 243, 0.15) 0%, transparent 25%),
        radial-gradient(circle at 50% 50%, rgba(255, 64, 129, 0.1) 0%, transparent 35%);
    z-index: -1;
    animation: pulse 10s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 0.5; }
    50% { opacity: 0.8; }
}

.container {
    width: 100%;
    max-width: 1400px;
    background: rgba(18, 22, 59, 0.6);
    border-radius: 20px;
    padding: 25px;
    box-shadow: 
        0 0 30px rgba(124, 77, 255, 0.3),
        inset 0 0 50px rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(15px);
    border: 1px solid rgba(124, 77, 255, 0.4);
    position: relative;
}

/* 顶部发光边框 */
.container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, 
        transparent, 
        #7c4dff, 
        #2196f3, 
        #7c4dff, 
        transparent);
    box-shadow: 0 0 10px #7c4dff;
    border-radius: 20px 20px 0 0;
}

/* ========== 头部样式 ========== */
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
    background: rgba(18, 22, 59, 0.7);
    border-radius: 15px;
    border: 1px solid rgba(124, 77, 255, 0.3);
    box-shadow: 0 0 20px rgba(124, 77, 255, 0.2);
    margin-bottom: 25px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 15px;
}

.logo-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, #7c4dff, #2196f3);
    border-radius: 12px;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(3, 1fr);
    gap: 3px;
    padding: 6px;
    box-shadow: 0 0 15px rgba(124, 77, 255, 0.5);
    animation: glow 2s ease-in-out infinite;
}

@keyframes glow {
    0%, 100% { box-shadow: 0 0 15px rgba(124, 77, 255, 0.5); }
    50% { box-shadow: 0 0 25px rgba(124, 77, 255, 0.8), 0 0 35px rgba(124, 77, 255, 0.5); }
}

.logo-icon div {
    background: white;
    border-radius: 2px;
    opacity: 0.8;
}

.logo-text h1 {
    font-size: 28px;
    background: linear-gradient(to right, #7c4dff, #2196f3);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: 2px;
    text-shadow: 0 0 10px rgba(124, 77, 255, 0.5);
    margin-bottom: 2px;
}

.logo-text p {
    font-size: 14px;
    color: #e0e0ff;
    opacity: 0.8;
}

.stats {
    display: flex;
    gap: 25px;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: rgba(30, 35, 80, 0.6);
    padding: 12px 20px;
    border-radius: 12px;
    min-width: 120px;
    border: 1px solid rgba(124, 77, 255, 0.3);
    box-shadow: 0 0 10px rgba(124, 77, 255, 0.1);
    transition: all 0.3s ease;
}

.stat-item:hover {
    transform: translateY(-3px);
    box-shadow: 0 0 20px rgba(124, 77, 255, 0.3);
}

.stat-item span:first-child {
    font-size: 13px;
    opacity: 0.8;
    margin-bottom: 8px;
    color: #2196f3;
}

#timer, #errors {
    font-size: 20px;
    font-weight: bold;
    color: #7c4dff;
    text-shadow: 0 0 10px rgba(124, 77, 255, 0.5);
}

.controls {
    display: flex;
    gap: 15px;
}

.btn {
    padding: 12px 20px;
    border: none;
    border-radius: 10px;
    background: rgba(30, 35, 80, 0.6);
    color: #e0e0ff;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.3s ease;
    border: 1px solid rgba(124, 77, 255, 0.3);
    font-size: 14px;
    font-weight: 500;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 0 20px rgba(124, 77, 255, 0.4);
}

.pause {
    background: rgba(255, 152, 0, 0.2);
    border-color: rgba(255, 152, 0, 0.4);
}

.pause:hover {
    background: rgba(255, 152, 0, 0.3);
    box-shadow: 0 0 20px rgba(255, 152, 0, 0.4);
}

.restart {
    background: rgba(33, 150, 243, 0.2);
    border-color: rgba(33, 150, 243, 0.4);
}

.restart:hover {
    background: rgba(33, 150, 243, 0.3);
    box-shadow: 0 0 20px rgba(33, 150, 243, 0.4);
}

.new-game {
    background: linear-gradient(135deg, #7c4dff, #2196f3);
    color: white;
    border: none;
    box-shadow: 0 0 20px rgba(124, 77, 255, 0.4);
}

.new-game:hover {
    box-shadow: 0 0 30px rgba(124, 77, 255, 0.6);
}

/* ========== 主内容区�?========== */
main {
    display: grid;
    grid-template-columns: 220px 1fr 320px;
    gap: 25px;
    margin-bottom: 25px;
}

.left-panel, .right-panel {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.panel-section {
    background: rgba(30, 35, 80, 0.6);
    border-radius: 15px;
    padding: 20px;
    border: 1px solid rgba(124, 77, 255, 0.3);
    box-shadow: 0 0 15px rgba(124, 77, 255, 0.1);
    transition: all 0.3s ease;
}

.panel-section:hover {
    box-shadow: 0 0 25px rgba(124, 77, 255, 0.2);
}

.section-title {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 18px;
    font-weight: 600;
    color: #7c4dff;
    font-size: 16px;
    text-shadow: 0 0 10px rgba(124, 77, 255, 0.3);
}

/* 左侧按钮 */
.side-btn {
    width: 100%;
    padding: 15px;
    background: rgba(30, 35, 80, 0.4);
    border: 1px solid rgba(124, 77, 255, 0.3);
    border-radius: 10px;
    color: #e0e0ff;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
    transition: all 0.3s ease;
    text-align: left;
    font-size: 14px;
}

.side-btn:hover {
    background: rgba(124, 77, 255, 0.2);
    transform: translateX(5px);
    box-shadow: 0 0 15px rgba(124, 77, 255, 0.3);
}

.hint-btn .badge {
    background: #ff4081;
    color: white;
    padding: 3px 8px;
    border-radius: 12px;
    font-size: 12px;
    margin-left: auto;
    box-shadow: 0 0 10px rgba(255, 64, 129, 0.5);
}

.toggle-switch {
    margin-left: auto;
    position: relative;
    width: 45px;
    height: 22px;
    background: rgba(124, 77, 255, 0.3);
    border-radius: 11px;
    display: flex;
    align-items: center;
    padding: 2px;
    border: 1px solid rgba(124, 77, 255, 0.4);
}

.toggle-label {
    font-size: 10px;
    color: #4caf50;
    margin-left: 4px;
    font-weight: bold;
}

.shortcut {
    margin-left: auto;
    font-size: 11px;
    opacity: 0.6;
    color: #2196f3;
}

/* ========== 数独棋盘 ========== */
.center-panel {
    display: flex;
    justify-content: center;
    align-items: center;
}

.sudoku-board {
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    grid-template-rows: repeat(9, 1fr);
    gap: 2px;
    width: 100%;
    max-width: 600px;
    aspect-ratio: 1/1;
    background: rgba(124, 77, 255, 0.2);
    border: 3px solid #7c4dff;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 
        0 0 30px rgba(124, 77, 255, 0.4),
        inset 0 0 50px rgba(0, 0, 0, 0.3);
    position: relative;
}

/* 棋盘扫描线效�?*/
.sudoku-board::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(45deg, 
        transparent 40%, 
        rgba(124, 77, 255, 0.1) 50%, 
        transparent 60%);
    animation: shimmer 3s ease-in-out infinite;
    pointer-events: none;
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}

.cell {
    background: rgba(18, 22, 59, 0.9);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 26px;
    font-weight: bold;
    cursor: pointer;
    position: relative;
    transition: all 0.2s ease;
    border: 1px solid rgba(124, 77, 255, 0.1);
}

.cell:hover {
    background: rgba(124, 77, 255, 0.2);
    box-shadow: inset 0 0 15px rgba(124, 77, 255, 0.3);
}

.cell.selected {
    background: rgba(124, 77, 255, 0.3);
    box-shadow: 
        0 0 20px rgba(124, 77, 255, 0.6),
        inset 0 0 20px rgba(124, 77, 255, 0.3);
    border: 2px solid #7c4dff;
    z-index: 1;
}

.cell.fixed {
    color: #e0e0ff;
    font-weight: bold;
    text-shadow: 0 0 10px rgba(224, 224, 255, 0.3);
}

.cell.user-input {
    color: #7c4dff;
    text-shadow: 0 0 10px rgba(124, 77, 255, 0.5);
}

.cell.error {
    color: #f44336;
    text-shadow: 0 0 10px rgba(244, 67, 54, 0.5);
    animation: shake 0.4s;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-6px); }
    75% { transform: translateX(6px); }
}

/* 3x3宫格边框 */
.cell:nth-child(3n):not(:nth-child(9n)) {
    border-right: 2px solid #7c4dff;
}

.cell:nth-child(n+19):nth-child(-n+27),
.cell:nth-child(n+46):nth-child(-n+54) {
    border-bottom: 2px solid #7c4dff;
}

/* ========== 右侧面板 ========== */
.number-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    margin-bottom: 18px;
}

.num-btn {
    height: 55px;
    font-size: 22px;
    font-weight: bold;
    background: rgba(30, 35, 80, 0.6);
    border: 1px solid rgba(124, 77, 255, 0.3);
    border-radius: 10px;
    color: #e0e0ff;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.2);
}

.num-btn:hover {
    background: rgba(124, 77, 255, 0.2);
    transform: scale(1.05);
    box-shadow: 0 0 20px rgba(124, 77, 255, 0.4);
}

.num-btn.active {
    background: linear-gradient(135deg, #7c4dff, #2196f3);
    color: white;
    box-shadow: 0 0 25px rgba(124, 77, 255, 0.6);
    border: 2px solid white;
}

.action-buttons {
    display: flex;
    gap: 12px;
}

.action-btn {
    flex: 1;
    padding: 12px;
    background: rgba(30, 35, 80, 0.6);
    border: 1px solid rgba(124, 77, 255, 0.3);
    border-radius: 10px;
    color: #e0e0ff;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all 0.3s ease;
    font-size: 14px;
}

.action-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 20px rgba(124, 77, 255, 0.4);
}

.clear:hover {
    background: rgba(244, 67, 54, 0.2);
    border-color: rgba(244, 67, 54, 0.4);
    box-shadow: 0 0 20px rgba(244, 67, 54, 0.3);
}

.erase:hover {
    background: rgba(255, 152, 0, 0.2);
    border-color: rgba(255, 152, 0, 0.4);
    box-shadow: 0 0 20px rgba(255, 152, 0, 0.3);
}

/* 主题选择�?*/
.theme-options {
    display: flex;
    justify-content: space-between;
    gap: 10px;
}

.theme-btn {
    width: 35px;
    height: 35px;
    border-radius: 50%;
    border: 2px solid transparent;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
}

.theme-btn:hover {
    transform: scale(1.15);
    box-shadow: 0 0 20px rgba(124, 77, 255, 0.5);
}

.theme-btn.active {
    border-color: white;
    box-shadow: 0 0 20px rgba(255, 255, 255, 0.6);
}

.theme-btn:nth-child(1) {
    background: linear-gradient(135deg, #7c4dff, #2196f3);
}

.theme-btn:nth-child(2) {
    background: #2196f3;
}

.theme-btn:nth-child(3) {
    background: #4caf50;
}

.theme-btn:nth-child(4) {
    background: #ff9800;
}

.theme-btn:nth-child(5) {
    background: #333;
}

/* 统计信息 */
.stat-row {
    display: flex;
    justify-content: space-between;
    margin-bottom: 12px;
    font-size: 14px;
    padding: 8px;
    background: rgba(30, 35, 80, 0.3);
    border-radius: 8px;
}

.progress-bar {
    height: 8px;
    background: rgba(30, 35, 80, 0.6);
    border-radius: 4px;
    margin-top: 12px;
    overflow: hidden;
    border: 1px solid rgba(124, 77, 255, 0.3);
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #7c4dff, #2196f3);
    border-radius: 4px;
    transition: width 0.5s ease;
    box-shadow: 0 0 10px rgba(124, 77, 255, 0.5);
}

/* ========== 底部激励语 ========== */
footer {
    display: flex;
    justify-content: center;
    padding: 20px 0;
}

.motivation-message {
    background: rgba(30, 35, 80, 0.6);
    padding: 15px 30px;
    border-radius: 25px;
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
    color: #7c4dff;
    box-shadow: 0 0 20px rgba(124, 77, 255, 0.3);
    border: 1px solid rgba(124, 77, 255, 0.4);
    font-size: 16px;
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-5px); }
}

/* ========== 响应式设计 ========== */

/* 默认隐藏移动端专用元素 */
.mobile-stats-bar,
.mobile-control-buttons,
.mobile-number-input,
.mobile-stats-panel {
    display: none;
}

/* 平板设备 */
@media (max-width: 1200px) {
    .container {
        padding: 20px;
    }
    
    main {
        grid-template-columns: 200px 1fr 300px;
        gap: 20px;
    }
    
    .sudoku-board {
        max-width: 500px;
    }
    
    header {
        padding: 12px 15px;
    }
}

/* 小平板大手机 */
@media (max-width: 992px) {
    .container {
        padding: 15px;
    }
    
    main {
        grid-template-columns: 180px 1fr;
        grid-template-rows: auto 1fr;
        gap: 15px;
    }
    
    .right-panel {
        grid-column: 1 / -1;
        grid-row: 2;
        flex-direction: row;
        flex-wrap: wrap;
        gap: 15px;
    }
    
    .panel-section {
        flex: 1;
        min-width: 200px;
        padding: 15px;
    }
    
    header {
        flex-wrap: wrap;
        gap: 15px;
    }
    
    .stats {
        gap: 15px;
    }
    
    .stat-item {
        min-width: 100px;
        padding: 10px 15px;
    }
    
    #timer, #errors {
        font-size: 18px;
    }
    
    .controls {
        width: 100%;
        justify-content: center;
    }
    
    .btn {
        padding: 10px 15px;
        font-size: 13px;
    }
}

/* 手机设备 */
@media (max-width: 768px) {
    body {
        padding: 0; /* 删除顶部距离 */
    }
    
    .container {
        padding: 8px; /* 减小内边距 */
        border-radius: 0; /* 移除圆角，更紧凑 */
        gap: 4px; /* 减小间距 */
    }
    
    /* ========== 第一行：Logo + 难度（单行显示）========== */
    header {
        flex-direction: row;
        flex-wrap: wrap;
        align-items: center;
        padding: 6px 8px; /* 减小内边距 */
        gap: 6px; /* 减小间距 */
        margin-bottom: 0; /* 移除底部边距 */
    }
    
    .logo {
        flex: 0 0 auto;
        display: flex;
        align-items: center;
        gap: 8px;
    }
    
    .logo-icon {
        width: 32px;
        height: 32px;
    }
    
    .logo-text h1 {
        font-size: 18px;
        margin: 0;
    }
    
    .logo-text p {
        font-size: 10px;
        margin: 0;
        opacity: 0.7;
    }
    
    /* 难度选择放在 Logo 右侧 */
    .stats {
        flex: 1;
        display: flex;
        justify-content: flex-end;
        gap: 8px;
    }
    
    .stat-item {
        min-width: auto;
        padding: 6px 10px;
    }
    
    .stat-item select {
        font-size: 12px;
        padding: 4px 8px;
    }
    
    /* 隐藏时间和错误（移到第二行）*/
    .stat-item:nth-child(2),
    .stat-item:nth-child(3) {
        display: none;
    }
    
    /* 隐藏顶部控制按钮 */
    .controls {
        display: none;
    }
    
    /* 显示移动端专用元素 */
    .mobile-stats-bar,
    .mobile-control-buttons,
    .mobile-number-input,
    .mobile-stats-panel {
        display: flex !important;
    }
    
    /* mobile-number-input 和 mobile-stats-panel 应该是 block */
    .mobile-number-input,
    .mobile-stats-panel {
        display: block !important;
    }
    
    main {
        grid-template-columns: 1fr 50px;
        grid-template-rows: auto 1fr;
        gap: 4px;
        margin-bottom: 0;
    }
    
    .mobile-stats-bar {
        display: flex;
        justify-content: space-between;
        background: rgba(30, 35, 80, 0.6);
        padding: 2px 10px;
        border-radius: 4px;
        border: 1px solid rgba(124, 77, 255, 0.3);
        grid-column: 1 / -1;
        grid-row: 1;
    }
    
    .mobile-stat-item {
        display: flex;
        align-items: center;
        gap: 6px;
        font-size: 13px;
        color: #e0e0ff;
    }
    
    .mobile-stat-item i {
        color: #7c4dff;
    }
    
    .left-panel {
        overflow: visible;
        padding: 0;
        position: absolute;
        left: 8px;
        top: 50%;
        transform: translateY(-50%);
        z-index: 10;
        display: none;
    }
    
    .center-panel {
        grid-column: 1;
        grid-row: 2;
        display: flex;
        justify-content: center;
        align-items: center;
    }
    
    .right-panel {
        grid-column: 2;
        grid-row: 2;
        display: flex;
        flex-direction: column;
        gap: 6px;
        padding: 0;
    }
    
    /* ========== 左侧图标列 ========== */
    .left-panel .panel-section {
        display: flex;
        flex-direction: column;
        gap: 8px;
        padding: 0;
        background: transparent;
        box-shadow: none;
        border: none;
    }
    
    /* 确保左侧按钮显示 */
    .left-panel .side-btn {
        display: flex !important;
    }
    
    .side-btn {
        width: 40px;
        height: 40px;
        min-width: 40px;
        padding: 0;
        margin: 0;
        border-radius: 8px;
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 16px;
        position: relative;
    }
    
    .side-btn i {
        margin: 0;
    }
    
    .side-btn span:not(.badge) {
        display: none;
    }
    
    .side-btn .badge {
        position: absolute;
        top: -5px;
        right: -5px;
        font-size: 10px;
        padding: 2px 5px;
        min-width: 18px;
        height: 18px;
    }
    
    /* ========== 右侧图标列 ========== */
    .right-panel .panel-section {
        padding: 0;
        background: transparent;
        box-shadow: none;
        border: none;
        display: none; /* 隐藏桌面端的面板内容 */
    }
    
    /* 显示移动端控制按钮（在右侧）*/
    .right-panel .mobile-control-buttons {
        display: flex !important;
        flex-direction: column;
        gap: 6px;
    }
    
    /* 数字输入区应该在棋盘下方，不在右侧 */
    .right-panel .number-input {
        display: none !important; /* 隐藏在右侧面板中 */
    }
    
    /* 统计信息也应该在棋盘下方，不在右侧 */
    .right-panel .stats-panel {
        display: none !important; /* 隐藏在右侧面板中 */
    }
    
    /* 隐藏所有标题 */
    .section-title {
        display: none;
    }
    
    /* 右侧控制按钮（新游戏、暂停、重开、提示）*/
    .mobile-control-buttons {
        display: flex;
        flex-direction: column;
        gap: 8px;
    }
    
    .mobile-control-btn {
        width: 40px;
        height: 40px;
        border-radius: 8px;
        border: 1px solid rgba(124, 77, 255, 0.4);
        background: rgba(30, 35, 80, 0.6);
        color: #e0e0ff;
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 16px;
        cursor: pointer;
        transition: all 0.3s ease;
    }
    
    .mobile-control-btn:hover {
        background: rgba(124, 77, 255, 0.3);
        box-shadow: 0 0 15px rgba(124, 77, 255, 0.5);
        transform: scale(1.05);
    }
    
    .mobile-control-btn:active {
        transform: scale(0.95);
    }
    
    /* ========== 棋盘优化 ========== */
    .sudoku-board {
        max-width: 100%;
        width: 100%;
        aspect-ratio: 1/1;
    }
    
    .cell {
        font-size: 16px;
    }
    
    /* ========== 数字键盘（棋盘下方，整屏宽度）========== */
    .mobile-number-input {
        width: 100%; /* 占满整个容器宽度 */
        display: block !important; /* 确保显示 */
        padding: 6px 4px; /* 上下6px与gap一致，左右4px防止贴边 */
        background: rgba(30, 35, 80, 0.4);
        border-radius: 4px; /* 减小圆角，与第二行一致 */
        margin-top: 4px; /* 与九宫格的间距 */
    }
    
    /* 隐藏 right-panel 内的 number-input */
    .right-panel > .number-input {
        display: none !important;
    }
    
    .number-grid {
        display: grid;
        grid-template-columns: repeat(9, 1fr);  /* 9个数字横向排列 */
        gap: 3px; /* 减小数字之间的间距 */
        padding: 0 4px; /* 添加左右内边距，防止贴边 */
    }
    
    .num-btn {
        height: 36px; /* 减小高度，确保不超出屏幕 */
        font-size: 14px; /* 稍微减小字体 */
        border-radius: 5px;
        padding: 0;
    }
    
    .action-buttons {
        display: flex;
        gap: 4px; /* 减小按钮间距 */
        margin-top: 4px; /* 减小顶部间距 */
    }
    
    .action-btn {
        flex: 1;
        padding: 8px;
        font-size: 12px;
        border-radius: 6px;
    }
    
    /* ========== 统计信息（数字键盘下方，整屏宽度）========== */
    .mobile-stats-panel {
        width: 100%; /* 占满整个容器宽度 */
        display: block !important; /* 确保显示 */
        padding: 6px 8px; /* 上下6px与gap一致，左右8px保持舒适 */
        background: rgba(30, 35, 80, 0.4);
        border-radius: 4px; /* 减小圆角，与第二行一致 */
        margin-top: 4px; /* 与数字键盘的间距 */
    }
    
    /* 隐藏 right-panel 内的 stats-panel */
    .right-panel > .stats-panel {
        display: none !important;
    }
    
    .stat-row {
        font-size: 12px;
        padding: 4px 0;
        margin-bottom: 4px;
    }
    
    .progress-bar {
        height: 4px;
        margin-top: 6px;
    }
    
    /* ========== 底部激励语 ========== */
    footer {
        width: 100%; /* 占满整个容器宽度 */
        padding: 6px 0; /* 与间距一致 */
        margin-top: 4px; /* 与统计信息的间距 */
    }
    
    .motivation-message {
        padding: 10px 15px;
        font-size: 12px;
        border-radius: 15px;
    }
    
    /* 隐藏主题选择器 */
    .theme-selector {
        display: none;
    }
}

/* 小屏幕手机 */
@media (max-width: 480px) {
    .container {
        padding: 10px;
    }
    
    .logo-text h1 {
        font-size: 18px;
    }
    
    .stat-item {
        min-width: 70px;
        padding: 6px 10px;
    }
    
    #timer, #errors {
        font-size: 14px;
    }
    
    .btn {
        padding: 6px 10px;
        font-size: 11px;
    }
    
    .cell {
        font-size: 16px;
    }
    
    .num-btn {
        height: 36px;
        font-size: 14px;
    }
    
    .side-btn {
        min-width: 100px;
        padding: 10px;
        font-size: 12px;
    }
}