/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', 'Microsoft YaHei', 'Arial', sans-serif;
    background: linear-gradient(135deg, #e8f5e8 0%, #dcedc8 100%);
    min-height: 100vh;
    margin: 0;
    padding: 0;
    background-attachment: fixed;
    background-size: cover;
    overflow-x: hidden;
    transform: none;
    position: relative;
}

/* 顶部导航 */
.navbar {
    position: static;
    top: auto;
    z-index: auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 12px 25px;
    background: linear-gradient(135deg, #a8e6cf 0%, #81c784 100%);
    box-shadow: 0 2px 10px rgba(129, 199, 132, 0.3);
    border-bottom: none;
}

.nav-left .brand {
    display: flex;
    align-items: center;
    gap: 10px;
    color: #1b5e20;
    font-weight: 700;
    font-size: 1.2rem;
    text-shadow: 0 1px 2px rgba(255, 255, 255, 0.3);
    font-family: 'Segoe UI', 'Microsoft YaHei', 'Arial', sans-serif;
}

.keyboard-icon {
    width: 40px;
    height: 40px;
    color: #2e7d32;
    filter: drop-shadow(0 1px 2px rgba(46, 125, 50, 0.3));
}

.brand-text {
    color: #1b5e20;
    font-weight: 700;
    letter-spacing: 0.3px;
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    background: #ffffff;
    color: #2e7d32;
    border: 2px solid #66bb6a;
    border-radius: 18px;
    padding: 8px 16px;
    font-size: 0.9rem;
    font-weight: 600;
    box-shadow: 0 2px 8px rgba(102, 187, 106, 0.2);
    transition: all 0.3s ease;
    font-family: 'Segoe UI', 'Microsoft YaHei', 'Arial', sans-serif;
    cursor: pointer;
}

.nav-btn:hover {
    background: #f1f8e9;
    transform: translateY(-1px);
    box-shadow: 0 3px 12px rgba(102, 187, 106, 0.3);
    border-color: #4caf50;
}

.btn-icon {
    width: 18px;
    height: 18px;
    color: currentColor;
    transition: transform 0.3s ease;
}

.nav-btn:hover .btn-icon {
    transform: scale(1.1);
}

.main-layout {
    display: flex;
    gap: 15px;
    padding: 15px;
    justify-content: center;
    align-items: stretch;
    max-width: 1400px;
    margin: 20px auto;
    width: 100%;
    position: relative;
    transform: none;
}

.leftbar {
    width: 220px;
    background: linear-gradient(135deg, #e8f5e8 0%, #dcedc8 100%);
    border-radius: 15px;
    padding: 20px 15px;
    box-shadow: 0 6px 20px rgba(212, 230, 212, 0.2);
    border: 2px solid #a5d6a7;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    position: relative;
    transform: none;
    flex-shrink: 0;
    height: 680px;
    overflow-y: auto;
}

.main-content {
    display: flex;
    justify-content: center;
    align-items: stretch;
    flex: 1;
}

.sidebar {
    width: 260px;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 12px;
    padding: 20px 15px;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(8px);
    display: flex;
    flex-direction: column;
    position: relative;
    transform: none;
    flex-shrink: 0;
    height: 680px;
}

@media (max-width: 1200px) {
    .main-layout {
        flex-direction: column;
        max-width: 100%;
        padding: 15px;
    }
    
    .sidebar {
        width: 100%;
        position: static;
        order: -1;
    }
    
    .main-content {
        align-items: center;
    }
}

@media (max-width: 1000px) {
    .main-layout {
        padding: 10px;
        gap: 15px;
    }
    
    .sidebar {
        padding: 15px;
    }
}

@media (max-width: 800px) {
    .main-layout {
        padding: 8px;
        gap: 10px;
    }
    
    .sidebar {
        padding: 12px;
    }
    
    .container {
        padding: 15px;
    }
}

/* 针对高DPI屏幕和缩放的适配 */
@media (-webkit-min-device-pixel-ratio: 1.5), (min-resolution: 144dpi) {
    .main-layout {
        max-width: 1200px;
    }
    
    .sidebar {
        width: 260px;
    }
}

/* 针对150%缩放的适配 */
@media (max-width: 1600px) and (min-width: 1201px) {
    .main-layout {
        max-width: 1200px;
        padding: 15px;
    }
    
    .sidebar {
        width: 260px;
        padding: 18px;
    }
}

.container {
    background: white;
    border-radius: 20px;
    padding: 20px 5px;
    box-shadow: 0 8px 20px rgba(220, 237, 200, 0.3);
    border: 2px solid #a5d6a7;
    width: calc(100% - 220px - 260px - 30px);
    min-width: 880px;
    max-width: 900px;
    display: flex;
    flex-direction: column;
    position: relative;
    transform: none;
    flex: 1;
    height: 680px;
    overflow-y: auto;
}

h1 {
    color: #5a67d8;
    font-size: 2.2em;
    margin-bottom: 15px;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.1);
}

.game-area {
    text-align: center;
    margin: 0;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    flex: 0 0 auto;
}

.target-key {
    font-size: 2.5em;
    color: #2e7d32;
    font-weight: 700;
    margin: 20px 0;
    padding: 25px 40px;
    border: 3px solid #81c784;
    border-radius: 20px;
    background: linear-gradient(135deg, #f1f8e9 0%, #dcedc8 100%);
    display: inline-block;
    min-width: 150px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(129, 199, 132, 0.2);
    font-family: 'Segoe UI', 'Microsoft YaHei', 'Arial', sans-serif;
    text-shadow: 0 2px 4px rgba(46, 125, 50, 0.1);
    position: relative;
    overflow: hidden;
}

.target-key::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.4), transparent);
    transition: left 0.5s ease;
}

.target-key:hover::before {
    left: 100%;
}

.target-key:hover {
    transform: scale(1.05);
    box-shadow: 0 12px 35px rgba(129, 199, 132, 0.3);
}

.target-key:hover {
    background: linear-gradient(135deg, #fed7d7, #feb2b2);
    transform: scale(1.05);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
}

.keyboard {
    background: white;
    border-radius: 20px;
    padding: 20px 45px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    border: 2px solid #e0e0e0;
    width: calc(100% - 5px);
    max-width: 100%;
    margin: 20px auto;
    box-sizing: border-box;
}

.keyboard-row {
    display: flex;
    justify-content: center;
    margin: 6px 0;
    gap: 6px;
}

.key {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border: 2px solid #dee2e6;
    border-radius: 14px;
    padding: 14px 16px;
    font-size: 1.2em;
    font-weight: 600;
    color: #495057;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    min-width: 55px;
    font-family: 'Segoe UI', 'Microsoft YaHei', 'Arial', sans-serif;
    position: relative;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
}

.key:hover {
    background: linear-gradient(135deg, #e9ecef 0%, #dee2e6 100%);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
    border-color: #adb5bd;
}

.key.active {
    background: linear-gradient(135deg, #66bb6a 0%, #4caf50 100%);
    color: white;
    transform: translateY(1px);
    box-shadow: 0 2px 6px rgba(102, 187, 106, 0.4);
    border-color: #388e3c;
}

.key.target {
    background: linear-gradient(135deg, #fff59d 0%, #ffee58 100%);
    color: #2e7d32;
    animation: targetBounce 1.5s infinite;
    box-shadow: 0 0 25px rgba(255, 238, 88, 0.6);
    border-color: #fbc02d;
}

@keyframes targetBounce {
    0%, 100% { 
        transform: scale(1) translateY(0);
    }
    25% { 
        transform: scale(1.05) translateY(-2px);
    }
    75% { 
        transform: scale(1.05) translateY(-2px);
    }
}

.key.correct {
    background: linear-gradient(135deg, #66bb6a 0%, #4caf50 100%);
    color: white;
    animation: correctBounce 0.6s ease;
}

@keyframes correctBounce {
    0% { transform: scale(1); }
    30% { transform: scale(1.15); }
    60% { transform: scale(0.95); }
    100% { transform: scale(1); }
}

.key.wrong {
    background: linear-gradient(135deg, #ef5350 0%, #f44336 100%);
    color: white;
    animation: wobble 0.5s ease;
}

@keyframes wobble {
    0%, 100% { transform: translateX(0) rotate(0deg); }
    15% { transform: translateX(-8px) rotate(-5deg); }
    30% { transform: translateX(6px) rotate(3deg); }
    45% { transform: translateX(-4px) rotate(-2deg); }
    60% { transform: translateX(3px) rotate(1deg); }
    75% { transform: translateX(-2px) rotate(-1deg); }
}

.space-key {
    min-width: 320px;
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    color: #495057;
    border-color: #dee2e6;
}

.stats {
    margin-bottom: 15px;
}

.stat-box {
    background: linear-gradient(135deg, #c8e6c9 0%, #a5d6a7 100%);
    color: #2e7d32;
    padding: 12px 10px;
    border-radius: 15px;
    margin-bottom: 8px;
    box-shadow: 0 5px 15px rgba(165, 214, 167, 0.3);
    text-align: center;
    border: 2px solid #81c784;
    font-family: 'Segoe UI', 'Microsoft YaHei', 'Arial', sans-serif;
}

.stat-number {
    font-size: 1.8em;
    font-weight: bold;
    color: #2e7d32;
    text-shadow: 0 2px 4px rgba(46, 125, 50, 0.2);
}

.controls {
    display: flex;
    flex-direction: column;
    gap: 10px;
    align-items: center;
    justify-content: center;
    margin-top: 15px;
}

.btn {
    background: linear-gradient(135deg, #c8e6c9 %, #a5d6a7 100%);
    color: #2e7d32;
    border: 2px solid #81c784;
    padding: 12px 30px;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(129, 199, 132, 0.4);
    font-family: 'Segoe UI', 'Microsoft YaHei', 'Arial', sans-serif;
    min-width: 200px;
    text-align: center;
}

.btn:hover {
    background: linear-gradient(135deg, #a5d6a7 0%, #c8e6c9 100%);
    transform: translateY(-3px);
    box-shadow: 0 6px 15px rgba(129, 199, 132, 0.4);
}

.btn:active, .btn.active {
    transform: translateY(-1px);
    box-shadow: 0 2px 6px rgba(129, 199, 132, 0.3);
    background: linear-gradient(135deg, #ffcc80 0%, #ffb74d 100%);
    border-color: #ff9800;
    color: #e65100;
}

.mode-selector {
    display: flex;
    flex-direction: column;
    gap: 12px;
    align-items: center;
    justify-content: center;
    width: 100%;
    margin: 20px 0;
    padding: 0 10px;
}

.mode-btn {
    background: linear-gradient(135deg, #c8e6c9 0%, #a5d6a7 100%);
    border: 2px solid #81c784;
    color: #2e7d32;
    padding: 15px 12px;
    border-radius: 15px;
    font-size: 1.1rem;
    font-weight: 600;
    font-family: 'Segoe UI', 'Microsoft YaHei', 'Arial', sans-serif;
    transition: all 0.3s ease;
    box-shadow: 0 3px 8px rgba(129, 199, 132, 0.3);
    margin: 0;
    width: 100%;
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 45px;
}

.mode-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(129, 199, 132, 0.4);
    background: linear-gradient(135deg, #a5d6a7 0%, #c8e6c9 100%);
}

.mode-btn.active {
    background: linear-gradient(135deg, #ffcc80 0%, #ffb74d 100%);
    color: #e65100;
    border-color: #ff9800;
    box-shadow: 0 4px 12px rgba(255, 152, 0, 0.4);
    transform: translateY(-1px);
}

/* 手机端适配 */
@media (max-width: 768px) {
    body {
        background: linear-gradient(135deg, #e8f5e8 0%, #dcedc8 100%);
        padding: 0;
        overflow-x: hidden;
    }

    /* 导航栏 */
    .navbar {
        padding: 10px 12px;
        flex-wrap: wrap;
        gap: 8px;
    }

    .nav-left .brand {
        font-size: 0.95rem;
        gap: 8px;
    }

    .keyboard-icon {
        width: 32px;
        height: 32px;
    }

    .brand-text {
        font-size: 0.95rem;
    }

    .nav-right {
        width: 100%;
        display: flex;
        justify-content: center;
        margin-top: 5px;
    }

    .nav-btn {
        padding: 6px 12px;
        font-size: 0.85rem;
        border-radius: 15px;
    }

    .btn-icon {
        width: 16px;
        height: 16px;
    }

    /* 主布局 */
    .main-layout {
        flex-direction: column;
        padding: 10px;
        gap: 10px;
        margin: 10px auto;
        max-width: 100%;
    }

    /* 左侧栏 */
    .leftbar {
        width: 100%;
        height: auto;
        padding: 15px 10px;
        order: 1;
    }

    .mode-selector {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 8px;
        margin: 10px 0;
    }

    .mode-btn {
        flex: 1 1 calc(50% - 4px);
        min-width: calc(50% - 4px);
        padding: 12px 8px;
        font-size: 0.95rem;
        min-height: 42px;
    }

    /* 主内容区 */
    .main-content {
        order: 2;
        width: 100%;
    }

    .container {
        width: 100%;
        min-width: auto;
        max-width: 100%;
        padding: 15px 8px;
        margin: 0;
        height: auto;
        border-radius: 15px;
    }

    /* 游戏区域 */
    .game-area {
        margin: 10px 0;
    }

    .target-key {
        font-size: 1.8em;
        padding: 18px 30px;
        margin: 15px 0;
        border-radius: 15px;
        min-width: 120px;
    }

    /* 键盘区域 */
    .keyboard {
        padding: 12px 8px;
        margin: 15px 0;
        border-radius: 12px;
        width: 100%;
        overflow-x: auto;
    }

    .keyboard-row {
        margin: 4px 0;
        gap: 3px;
        justify-content: center;
    }

    .key {
        padding: 8px 6px;
        font-size: 0.85em;
        min-width: 32px;
        border-radius: 8px;
        box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    }

    .key[style*="min-width: 80px"] {
        min-width: 50px !important;
        font-size: 0.75em;
    }

    .key[style*="min-width: 60px"] {
        min-width: 42px !important;
        font-size: 0.75em;
    }

    .key[style*="min-width: 70px"] {
        min-width: 45px !important;
        font-size: 0.75em;
    }

    .key[style*="min-width: 90px"] {
        min-width: 52px !important;
        font-size: 0.75em;
    }

    .key[style*="min-width: 50px"] {
        min-width: 38px !important;
        font-size: 0.75em;
    }

    .space-key {
        min-width: 180px !important;
        font-size: 0.85em;
    }

    /* 右侧栏 */
    .sidebar {
        width: 100%;
        height: auto;
        padding: 15px 12px;
        order: 3;
        border-radius: 15px;
    }

    .stats {
        display: flex;
        flex-direction: row;
        gap: 8px;
        margin-bottom: 12px;
    }

    .stat-box {
        flex: 1;
        padding: 10px 8px;
        border-radius: 12px;
        margin-bottom: 0;
    }

    .stat-box div:first-child {
        font-size: 0.85rem;
    }

    .stat-number {
        font-size: 1.5em;
    }

    /* 控制按钮 */
    .controls {
        gap: 8px;
        margin-top: 12px;
    }

    .btn {
        padding: 10px 20px;
        font-size: 0.95rem;
        border-radius: 20px;
        min-width: 150px;
    }

    /* 模态弹窗 */
    .modal-dialog {
        max-width: 95vw;
        border-radius: 15px;
    }

    .modal-header {
        padding: 12px 15px;
    }

    .modal-title {
        font-size: 1.1em;
    }

    .modal-close {
        width: 35px;
        height: 35px;
        font-size: 1.5rem;
    }

    .modal-body {
        padding: 12px;
    }

    .tutorial-image {
        max-height: calc(90vh - 70px);
        border-radius: 8px;
    }

    /* 指法提示气泡 */
    .finger-hint-bubble {
        padding: 10px 18px;
        font-size: 0.95em;
        border-radius: 25px;
    }
}

/* 小屏手机适配 (宽度小于 480px) */
@media (max-width: 480px) {
    .navbar {
        padding: 8px 10px;
    }

    .nav-left .brand {
        font-size: 0.85rem;
    }

    .keyboard-icon {
        width: 28px;
        height: 28px;
    }

    .nav-btn {
        padding: 5px 10px;
        font-size: 0.8rem;
        gap: 4px;
    }

    .mode-btn {
        font-size: 0.85rem;
        padding: 10px 6px;
    }

    .target-key {
        font-size: 1.5em;
        padding: 15px 25px;
    }

    .keyboard {
        padding: 10px 5px;
    }

    .keyboard-row {
        gap: 2px;
        margin: 3px 0;
    }

    .key {
        padding: 6px 4px;
        font-size: 0.75em;
        min-width: 28px;
    }

    .key[style*="min-width: 80px"] {
        min-width: 42px !important;
        font-size: 0.65em;
    }

    .key[style*="min-width: 60px"],
    .key[style*="min-width: 70px"] {
        min-width: 38px !important;
        font-size: 0.65em;
    }

    .key[style*="min-width: 90px"] {
        min-width: 45px !important;
        font-size: 0.65em;
    }

    .key[style*="min-width: 50px"] {
        min-width: 32px !important;
        font-size: 0.65em;
    }

    .space-key {
        min-width: 140px !important;
        font-size: 0.75em;
    }

    .stat-box {
        padding: 8px 6px;
    }

    .stat-box div:first-child {
        font-size: 0.75rem;
    }

    .stat-number {
        font-size: 1.3em;
    }

    .btn {
        padding: 8px 16px;
        font-size: 0.9rem;
        min-width: 130px;
    }
}

/* 模态弹窗 */
.modal { display: none; }
.modal.show { display: block; }
.modal-backdrop {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    z-index: 2000;
    backdrop-filter: blur(5px);
}
.modal-dialog {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: auto;
    max-width: 90vw;
    background: linear-gradient(135deg, #e8f5e8 0%, #dcedc8 100%);
    border-radius: 25px;
    box-shadow: 0 20px 50px rgba(129, 199, 132, 0.3);
    overflow: hidden;
    max-height: 90vh;
    display: flex;
    flex-direction: column;
    z-index: 2001;
    border: 3px solid #a5d6a7;
}
.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 15px 20px;
    background: linear-gradient(135deg, #a8e6cf 0%, #81c784 100%);
    color: #1b5e20;
    font-family: 'Segoe UI', 'Microsoft YaHei', 'Arial', sans-serif;
    flex-shrink: 0;
}
.modal-title { 
    font-weight: 800;
    font-size: 1.3em;
    text-shadow: 0 1px 2px rgba(255, 255, 255, 0.3);
}
.modal-close {
    background: rgba(255, 255, 255, 0.3);
    color: #1b5e20;
    border: none;
    font-size: 1.8rem;
    line-height: 1;
    cursor: pointer;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}
.modal-close:hover {
    background: rgba(255, 255, 255, 0.5);
    transform: scale(1.1);
}
.modal-body { 
    padding: 15px; 
    overflow: hidden;
    font-family: 'Segoe UI', 'Microsoft YaHei', 'Arial', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
}
.tutorial-image {
    display: block;
    width: auto;
    height: auto;
    max-width: 100%;
    max-height: calc(90vh - 80px);
    object-fit: contain;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}
.modal-tip { 
    margin-top: 15px; 
    font-size: 1rem; 
    color: #2e7d32;
    text-align: center;
    font-weight: 600;
}

/* 指法提示气泡 */
.finger-hint-bubble {
    position: fixed;
    background: linear-gradient(135deg, #ff9a9e 0%, #fecfef 100%);
    color: white;
    padding: 12px 24px;
    border-radius: 30px;
    font-size: 1.1em;
    font-weight: bold;
    z-index: 9999;
    pointer-events: none;
    box-shadow: 0 6px 20px rgba(255, 154, 158, 0.4);
    white-space: nowrap;
    transition: all 0.3s ease;
    border: 2px solid #ff6b6b;
    font-family: 'Segoe UI', 'Microsoft YaHei', 'Arial', sans-serif;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
}

/* 设置按钮图标和文字样式 */
#settingsBtn {
    display: flex;
    align-items: center;
    gap: 6px;
    position: relative;
    overflow: hidden;
}

#settingsBtn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(129, 199, 132, 0.2), transparent);
    transition: left 0.5s ease;
}

#settingsBtn:hover::before {
    left: 100%;
}

#settingsBtn.active {
    background: linear-gradient(135deg, #66bb6a 0%, #4caf50 100%);
    color: #ffffff;
    border-color: #4caf50;
    box-shadow: 0 3px 12px rgba(76, 175, 80, 0.4);
}

#settingsBtn.active .btn-icon {
    animation: checkBounce 0.6s ease;
    color: #ffffff;
}

#settingsBtn:not(.active) {
    background: linear-gradient(135deg, #ef5350 0%, #e53935 100%);
    color: #ffffff;
    border-color: #d32f2f;
    box-shadow: 0 3px 12px rgba(239, 83, 80, 0.4);
}

@keyframes checkBounce {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.2) rotate(10deg); }
}

#tutorialBtn {
    position: relative;
    background: linear-gradient(135deg, #81c784 0%, #66bb6a 100%);
    color: #ffffff;
    border-color: #66bb6a;
    box-shadow: 0 2px 8px rgba(102, 187, 106, 0.3);
}

#tutorialBtn:hover {
    background: linear-gradient(135deg, #66bb6a 0%, #4caf50 100%);
    box-shadow: 0 3px 12px rgba(102, 187, 106, 0.4);
}

#tutorialBtn .btn-icon {
    animation: lightPulse 2s ease-in-out infinite;
    color: #ffffff;
}

@keyframes lightPulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.85; }
}

#tutorialBtn:hover .btn-icon {
    animation: lightSpin 0.6s ease;
}

@keyframes lightSpin {
    0% { transform: rotate(0deg) scale(1); }
    50% { transform: rotate(180deg) scale(1.15); }
    100% { transform: rotate(360deg) scale(1); }
}

/* 确保按钮内的子元素不阻止点击事件 */
.nav-btn .btn-icon,
.nav-btn span {
    pointer-events: none;
}

#settingsIcon {
    display: inline-block;
    min-width: 20px;
    text-align: center;
}