* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', 'Microsoft YaHei', 'PingFang SC', sans-serif;
}

:root {
    --primary-color: #4361ee;
    --primary-light: #6a8aff;
    --primary-dark: #2a4dca;
    --secondary-color: #3a0ca3;
    --accent-color: #4cc9f0;
    --accent-light: #80d9f7;
    --light-color: #f8f9fa;
    --dark-color: #1a1a2e;
    --gray-dark: #2d3047;
    --gray-medium: #6c757d;
    --gray-light: #e9ecef;
    --success-color: #2ecc71;
    --warning-color: #f39c12;
    --danger-color: #e74c3c;
    --info-color: #3498db;
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
    --box-shadow-lg: 0 15px 50px rgba(0, 0, 0, 0.15);
    --box-shadow-hover: 0 12px 40px rgba(67, 97, 238, 0.2);
    --transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    --transition-slow: all 0.5s cubic-bezier(0.19, 1, 0.22, 1);
}

body {
    background: linear-gradient(135deg, #f5f7ff 0%, #f0f4ff 100%);
    color: var(--dark-color);
    line-height: 1.7;
    display: flex;
    min-height: 100vh;
    overflow-x: hidden;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 20px;
}

::-webkit-scrollbar {
    width: 10px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 10px;
}

::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 10px;
    transition: var(--transition);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-dark);
}

.sidebar {
    width: 280px;
    background: linear-gradient(180deg, var(--dark-color) 0%, var(--gray-dark) 100%);
    color: white;
    display: flex;
    flex-direction: column;
    transition: var(--transition-slow);
    position: fixed;
    height: 100vh;
    z-index: 1000;
    box-shadow: var(--box-shadow-lg);
    overflow: hidden;
}

.sidebar::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, rgba(67, 97, 238, 0.1) 0%, rgba(58, 12, 163, 0.05) 100%);
    z-index: -1;
}

.sidebar-header {
    padding: 28px 24px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative;
    background: rgba(0, 0, 0, 0.2);
}

.sidebar-header h2 {
    font-size: 1.5rem;
    font-weight: 700;
    white-space: nowrap;
    overflow: hidden;
    background: linear-gradient(90deg, #fff 0%, var(--accent-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: 0.5px;
}

.nav-links {
    flex: 1;
    padding: 20px 0;
    overflow-y: auto;
}

.nav-item {
    list-style: none;
    margin: 5px 15px;
    border-radius: var(--border-radius-sm);
    overflow: hidden;
}

.nav-link {
    display: flex;
    align-items: center;
    padding: 18px 20px;
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    transition: var(--transition);
    white-space: nowrap;
    overflow: hidden;
    position: relative;
}

.nav-link::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 4px;
    background: var(--accent-color);
    transform: scaleY(0);
    transition: var(--transition);
}

.nav-link:hover, .nav-link.active {
    background: rgba(255, 255, 255, 0.1);
    color: white;
    padding-left: 24px;
}

.nav-link:hover::before, .nav-link.active::before {
    transform: scaleY(1);
}

.nav-link i {
    font-size: 1.3rem;
    width: 28px;
    margin-right: 16px;
    flex-shrink: 0;
    text-align: center;
}

.sidebar-footer {
    padding: 24px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.7);
    background: rgba(0, 0, 0, 0.2);
}

/* ===== 侧边栏收缩/展开 ===== */
.sidebar.collapsed {
    width: 72px;
}

.sidebar.collapsed .sidebar-header {
    padding: 20px 0;
    justify-content: center;
}

.sidebar.collapsed .sidebar-header h2 {
    display: none;
}

.sidebar.collapsed .nav-links {
    padding: 16px 0;
}

.sidebar.collapsed .nav-item {
    margin: 4px 10px;
}

.sidebar.collapsed .nav-link {
    justify-content: center;
    padding: 14px 0;
    border-radius: 10px;
}

.sidebar.collapsed .nav-link span {
    display: none;
}

.sidebar.collapsed .nav-link i {
    margin-right: 0;
    font-size: 1.25rem;
}

.sidebar.collapsed .nav-link:hover,
.sidebar.collapsed .nav-link.active {
    padding-left: 0;
    background: rgba(255, 255, 255, 0.12);
}

.sidebar.collapsed .nav-link::before {
    width: 3px;
    border-radius: 0 3px 3px 0;
}

.sidebar.collapsed .sidebar-footer {
    padding: 16px 8px;
}

.sidebar.collapsed .sidebar-footer p {
    display: none;
}

/* 收缩时导航项 tooltip */
.sidebar.collapsed .nav-link {
    position: relative;
}
.sidebar.collapsed .nav-link::after {
    content: attr(data-tooltip);
    position: absolute;
    left: calc(100% + 12px);
    top: 50%;
    transform: translateY(-50%) translateX(-4px);
    background: var(--dark-color);
    color: white;
    padding: 6px 12px;
    border-radius: 8px;
    font-size: 0.8rem;
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s, transform 0.2s;
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
    z-index: 1001;
}
.sidebar.collapsed .nav-link:hover::after {
    opacity: 1;
    transform: translateY(-50%) translateX(0);
}

.main-content.expanded {
    margin-left: 72px;
    max-width: calc(100% - 72px);
}

/* ===== 侧边栏切换按钮 ===== */
.toggle-btn {
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.12);
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.85rem;
    cursor: pointer;
    padding: 0;
    border-radius: 10px;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    flex-shrink: 0;
}

.toggle-btn:hover {
    background: rgba(255, 255, 255, 0.15);
    color: white;
    border-color: rgba(255, 255, 255, 0.25);
}

.toggle-btn i {
    transition: transform 0.3s ease;
}

.sidebar.collapsed .toggle-btn i {
    transform: rotate(180deg);
}

/* ===== 移动端菜单按钮 ===== */
.mobile-menu-btn {
    display: none;
    position: fixed;
    top: 25px;
    left: 25px;
    z-index: 999;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    border: none;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
}

.mobile-menu-btn:hover {
    transform: scale(1.1);
}

.main-content {
    flex: 1;
    margin-left: 280px;
    padding: 30px;
    transition: var(--transition-slow);
    max-width: calc(100% - 280px);
}

.section {
    background: white;
    border-radius: var(--border-radius);
    padding: 40px;
    margin-bottom: 40px;
    box-shadow: var(--box-shadow);
    display: none;
    border: 1px solid rgba(0, 0, 0, 0.05);
    position: relative;
    overflow: hidden;
}

.section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
}

.section.active {
    display: block;
    animation: fadeInUp 0.8s cubic-bezier(0.19, 1, 0.22, 1);
}

@keyframes fadeInUp {
    from { 
        opacity: 0; 
        transform: translateY(30px); 
    }
    to { 
        opacity: 1; 
        transform: translateY(0); 
    }
}

.section-header {
    margin-bottom: 35px;
    padding-bottom: 20px;
    border-bottom: 2px solid var(--gray-light);
    position: relative;
}

.section-header::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 80px;
    height: 2px;
    background: var(--primary-color);
}

.section-header h2 {
    color: var(--dark-color);
    font-size: 2.2rem;
    display: flex;
    align-items: center;
    font-weight: 700;
}

.section-header h2 i {
    margin-right: 15px;
    color: var(--primary-color);
    background: rgba(67, 97, 238, 0.1);
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.section-header p {
    font-size: 1.1rem;
    color: var(--gray-medium);
    margin-top: 10px;
    max-width: 800px;
}

.content-card {
    padding: 30px;
    border-radius: var(--border-radius);
    background: white;
    margin-bottom: 30px;
    border: 1px solid rgba(0, 0, 0, 0.05);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.03);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.content-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--box-shadow-hover);
}

.content-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background: linear-gradient(to bottom, var(--primary-color), var(--accent-color));
}

.content-card h3 {
    color: var(--dark-color);
    margin-bottom: 20px;
    font-size: 1.5rem;
    display: flex;
    align-items: center;
}

.content-card h3 i {
    margin-right: 12px;
    color: var(--primary-color);
}

.question-container {
    margin-bottom: 30px;
    padding: 25px;
    border-radius: var(--border-radius);
    background: linear-gradient(135deg, #f8f9ff 0%, #f0f2ff 100%);
    border-left: 5px solid var(--primary-color);
    transition: var(--transition);
}

.question-container:hover {
    transform: translateX(5px);
}

.question {
    font-weight: 700;
    margin-bottom: 20px;
    font-size: 1.2rem;
    line-height: 1.6;
    color: var(--dark-color);
}

.options {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.option {
    padding: 16px 20px;
    background: white;
    border-radius: var(--border-radius-sm);
    border: 2px solid var(--gray-light);
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
    display: flex;
    align-items: center;
    position: relative;
    overflow: hidden;
}

.option::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    width: 4px;
    height: 100%;
    background: var(--gray-light);
    transition: var(--transition);
}

.option:hover {
    background: rgba(67, 97, 238, 0.05);
    border-color: var(--primary-light);
    transform: translateX(5px);
}

.option:hover::before {
    background: var(--primary-color);
}

.option.selected {
    background: rgba(67, 97, 238, 0.1);
    border-color: var(--primary-color);
    color: var(--primary-dark);
}

.option.selected::before {
    background: var(--primary-color);
}

.option.correct {
    background: rgba(46, 204, 113, 0.15);
    border-color: var(--success-color);
    color: var(--success-color);
}

.option.correct::before {
    background: var(--success-color);
}

.option.incorrect {
    background: rgba(231, 76, 60, 0.1);
    border-color: var(--danger-color);
    color: var(--danger-color);
}

.option.incorrect::before {
    background: var(--danger-color);
}

.btn {
    padding: 14px 32px;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    letter-spacing: 0.5px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    box-shadow: 0 8px 20px rgba(67, 97, 238, 0.3);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 25px rgba(67, 97, 238, 0.4);
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary-color) 100%);
}

.btn-secondary {
    background: white;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

.btn-success {
    background: linear-gradient(135deg, var(--success-color) 0%, #27ae60 100%);
    color: white;
    box-shadow: 0 8px 20px rgba(46, 204, 113, 0.3);
}

.btn-success:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 25px rgba(46, 204, 113, 0.4);
}

.btn-lg {
    padding: 18px 40px;
    font-size: 1.1rem;
}

.learning-objectives {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin: 30px 0;
}

.objective-card {
    background: linear-gradient(135deg, #f8f9ff 0%, #f0f2ff 100%);
    padding: 25px;
    border-radius: var(--border-radius);
    text-align: center;
    transition: var(--transition);
    border: 1px solid rgba(67, 97, 238, 0.1);
}

.objective-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--box-shadow-hover);
}

.objective-card i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.objective-card h4 {
    color: var(--dark-color);
    margin-bottom: 10px;
    font-size: 1.1rem;
}

.objective-card p {
    color: var(--gray-medium);
    font-size: 0.9rem;
    line-height: 1.6;
}

.video-container {
    margin: 20px 0;
    background: linear-gradient(135deg, #f8f9ff 0%, #f0f2ff 100%);
    padding: 20px;
    border-radius: var(--border-radius);
    border: 1px solid rgba(67, 97, 238, 0.1);
}

.video-container h5 {
    color: var(--dark-color);
    margin-bottom: 15px;
    font-size: 1.1rem;
}

.video-caption {
    text-align: center;
    color: var(--gray-medium);
    font-size: 0.9rem;
    margin-top: 10px;
    font-style: italic;
}

.discussion-question {
    background: linear-gradient(135deg, #fff9e6 0%, #fff3cd 100%);
    padding: 20px;
    border-radius: var(--border-radius);
    margin: 15px 0;
    border-left: 4px solid var(--warning-color);
}

.discussion-question h4 {
    color: var(--dark-color);
    margin-bottom: 10px;
    display: flex;
    align-items: center;
}

.discussion-question h4 i {
    margin-right: 10px;
    color: var(--warning-color);
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    background: white;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
}

.data-table th {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 15px;
    text-align: center;
    font-weight: 600;
}

.data-table td {
    padding: 12px 15px;
    text-align: center;
    border-bottom: 1px solid var(--gray-light);
}

.data-table tr:hover {
    background: rgba(67, 97, 238, 0.05);
}

.formula {
    background: linear-gradient(135deg, #e8f4f8 0%, #d1e8f0 100%);
    padding: 15px 25px;
    border-radius: var(--border-radius);
    font-family: 'Times New Roman', serif;
    font-size: 1.3rem;
    text-align: center;
    margin: 15px 0;
    border-left: 4px solid var(--info-color);
    color: var(--dark-color);
}

.image-container {
    margin: 20px 0;
    text-align: center;
}

.image-container img {
    max-width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.image-caption {
    text-align: center;
    color: var(--gray-medium);
    font-size: 0.9rem;
    margin-top: 10px;
    font-style: italic;
}

.multi-image-container {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    justify-content: center;
}

.image-item {
    flex: 1;
    min-width: 250px;
    max-width: 400px;
}

.multi-select-note {
    background: rgba(243, 156, 18, 0.1);
    padding: 10px 15px;
    border-radius: var(--border-radius-sm);
    margin-bottom: 15px;
    color: var(--warning-color);
    font-weight: 600;
}

.result-container {
    background: linear-gradient(135deg, #e8f8f0 0%, #d4f0e0 100%);
    padding: 30px;
    border-radius: var(--border-radius);
    margin-top: 30px;
    display: none;
    border: 2px solid var(--success-color);
}

.result-container.show {
    display: block;
    animation: fadeInUp 0.5s ease;
}

.result-container h3 {
    color: var(--success-color);
    margin-bottom: 20px;
    font-size: 1.5rem;
}

.result-container .score {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--dark-color);
    margin-bottom: 15px;
}

.explanation {
    background: white;
    padding: 25px;
    border-radius: var(--border-radius);
    margin-top: 20px;
    border: 1px solid var(--gray-light);
}

.explanation h4 {
    color: var(--primary-color);
    margin-bottom: 15px;
    font-size: 1.2rem;
}

.error-analysis-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    margin-top: 20px;
}

.error-item {
    background: linear-gradient(135deg, #fff5f5 0%, #ffe8e8 100%);
    padding: 25px;
    border-radius: var(--border-radius);
    border-left: 4px solid var(--danger-color);
}

.error-item h4 {
    color: var(--danger-color);
    margin-bottom: 15px;
    display: flex;
    align-items: center;
}

.error-item h4 i {
    margin-right: 10px;
}

.error-features {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-top: 15px;
}

.error-features .feature {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px;
    background: white;
    border-radius: var(--border-radius-sm);
}

.error-features .feature i {
    color: var(--primary-color);
}

.method-header {
    background: linear-gradient(135deg, #e8f4f8 0%, #d1e8f0 100%);
    padding: 20px;
    border-radius: var(--border-radius);
    margin-bottom: 20px;
}

.method-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 30px;
    height: 30px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    margin-right: 10px;
    font-weight: 700;
}

.timeline {
    position: relative;
    padding-left: 30px;
    margin: 20px 0;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 3px;
    background: linear-gradient(to bottom, var(--primary-color), var(--accent-color));
}

.timeline-item {
    position: relative;
    padding: 15px 0 15px 30px;
    border-bottom: 1px solid var(--gray-light);
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -6px;
    top: 20px;
    width: 15px;
    height: 15px;
    background: var(--primary-color);
    border-radius: 50%;
    border: 3px solid white;
    box-shadow: 0 0 0 3px var(--primary-color);
}

.timeline-year {
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 5px;
}

.timeline-content {
    color: var(--dark-color);
}

.eco-tips {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin-top: 15px;
}

.eco-tip {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 15px;
    background: linear-gradient(135deg, #e8f8f0 0%, #d4f0e0 100%);
    border-radius: var(--border-radius);
}

.eco-tip i {
    font-size: 1.5rem;
    color: var(--success-color);
}

.challenge-task {
    background: linear-gradient(135deg, #fff9e6 0%, #fff3cd 100%);
    padding: 25px;
    border-radius: var(--border-radius);
    margin: 20px 0;
    border-left: 4px solid var(--warning-color);
}

.challenge-task h4 {
    color: var(--dark-color);
    margin-bottom: 15px;
}

.sensor-status {
    display: flex;
    gap: 25px;
    flex-wrap: wrap;
    margin-top: 20px;
}

.sensor {
    flex: 1;
    min-width: 250px;
    padding: 25px;
    background: white;
    border-radius: var(--border-radius);
    border: 1px solid var(--gray-light);
    display: flex;
    flex-direction: column;
    align-items: center;
    transition: var(--transition);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.03);
}

.sensor:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
}

.sensor-value {
    font-size: 2.8rem;
    font-weight: 800;
    color: var(--primary-color);
    margin: 15px 0;
    font-family: 'Courier New', monospace;
    text-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

.sensor.connected {
    border-color: var(--success-color);
    background: rgba(46, 204, 113, 0.03);
}

.sensor.connected .sensor-value {
    color: var(--success-color);
}

.chart-container {
    margin-top: 30px;
    height: 400px;
    background: white;
    border-radius: var(--border-radius);
    border: 1px solid var(--gray-light);
    padding: 20px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.03);
}

.button-container {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    margin: 20px 0;
}

.bluetooth-btn {
    padding: 12px 24px;
    background: linear-gradient(135deg, #00b4db 0%, #0083b0 100%);
    color: white;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
    transition: var(--transition);
}

.bluetooth-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 180, 219, 0.3);
}

.bluetooth-btn:disabled {
    background: var(--gray-light);
    color: var(--gray-medium);
    cursor: not-allowed;
    transform: none;
}

.bluetooth-btn.pulse {
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% {
        box-shadow: 0 0 0 0 rgba(0, 180, 219, 0.4);
    }
    70% {
        box-shadow: 0 0 0 15px rgba(0, 180, 219, 0);
    }
    100% {
        box-shadow: 0 0 0 0 rgba(0, 180, 219, 0);
    }
}

.status-text {
    font-size: 0.9rem;
    color: var(--gray-medium);
    margin-top: 10px;
}

.result-box {
    display: flex;
    flex-wrap: wrap;
    gap: 25px;
    margin-top: 30px;
}

.result-item {
    flex: 1;
    min-width: 220px;
    padding: 25px;
    background: linear-gradient(135deg, #f8f9ff 0%, #f0f2ff 100%);
    border-radius: var(--border-radius);
    text-align: center;
    border: 1px solid rgba(67, 97, 238, 0.1);
}

.result-item h4 {
    color: var(--gray-medium);
    font-size: 0.9rem;
    margin-bottom: 10px;
}

.result-item .result-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
}

.result-item p {
    color: var(--gray-medium);
    font-size: 0.85rem;
    margin-top: 5px;
}

.table-container {
    overflow-x: auto;
}

.discussion-answer {
    background: linear-gradient(135deg, #e8f8f0 0%, #d4f0e0 100%);
    padding: 25px;
    border-radius: var(--border-radius);
    margin: 20px 0;
    border-left: 4px solid var(--success-color);
}

.discussion-answer h5 {
    color: var(--success-color);
    margin-bottom: 15px;
    font-size: 1.1rem;
}

.discussion-answer p {
    margin-bottom: 10px;
    line-height: 1.8;
}

/* ===== thinking.html 误差分析样式 ===== */
.image-grid {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    justify-content: center;
}
.image-label {
    font-weight: 600;
    margin-bottom: 10px;
    color: var(--dark-color);
}
.analysis-image {
    max-width: 100%;
    border-radius: var(--border-radius);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}
.analysis-image-large {
    max-width: 100%;
    border-radius: var(--border-radius);
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}
.image-single {
    text-align: center;
    margin: 15px 0;
}
.formula-box {
    background: linear-gradient(135deg, #f0f4ff, #e8ecf8);
    padding: 20px;
    border-radius: var(--border-radius);
    margin: 15px 0;
    border-left: 4px solid var(--primary-color);
}
.formula-title {
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 10px;
}
.theory-section { margin-bottom: 20px; }
.visualization-section { margin-top: 20px; }
.result-section { margin-top: 15px; }
.result-icon { font-size: 1.5rem; color: var(--primary-color); margin-right: 10px; }
.result-content { flex: 1; }
.result-title { font-weight: 600; color: var(--dark-color); margin-bottom: 5px; }
.method-description { color: var(--gray-medium); font-size: 0.95rem; }
.analysis-content { padding: 10px 0; }

.particles-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -1;
    overflow: hidden;
}

.particle {
    position: absolute;
    background: radial-gradient(circle, var(--primary-color) 0%, transparent 70%);
    border-radius: 50%;
    animation: float linear infinite;
}

@keyframes float {
    0% {
        transform: translateY(100vh) rotate(0deg);
        opacity: 0;
    }
    10% {
        opacity: 1;
    }
    90% {
        opacity: 1;
    }
    100% {
        transform: translateY(-100vh) rotate(720deg);
        opacity: 0;
    }
}

@media (max-width: 992px) {
    .sidebar {
        transform: translateX(-100%);
        width: 280px;
    }
    .sidebar.active {
        transform: translateX(0);
    }
    .main-content {
        margin-left: 0;
        max-width: 100%;
        padding: 20px;
    }
    .mobile-menu-btn {
        display: block;
    }
}

@media (max-width: 768px) {
    .sidebar {
        width: 80px;
    }

    .sidebar .nav-link span {
        display: none;
    }

    .main-content {
        margin-left: 80px;
        max-width: calc(100% - 80px);
    }

    .section {
        padding: 20px;
    }

    .section-header h2 {
        font-size: 1.5rem;
    }

    .section-header h2 i {
        width: 40px;
        height: 40px;
    }
}