/* 全局样式 */

/* 页面加载动画 */
.page-loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.95);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.page-loader.hidden {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

.loader-content {
    text-align: center;
}

.loader-spinner {
    width: 50px;
    height: 50px;
    border: 3px solid #f3f3f3;
    border-top: 3px solid #4361ee;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

.loader-content p {
    color: #495057;
    font-size: 1.1rem;
    font-weight: 500;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 匿名评课链接样式 */
.anonymous-link {
    margin-top: 10px;
}

/* 日期筛选组样式 */
.date-filter-group {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    margin: 0 10px;
}

.date-filter-group label {
    font-size: 12px;
    color: #666;
}

.date-filter-group input {
    padding: 4px;
    font-size: 12px;
    width: auto;
}

/* 报告页面样式 */
.report-section-title {
    font-size: 1.1rem;
    margin-bottom: 1rem;
    padding-left: 0.75rem;
    border-left: 3px solid var(--primary-color);
}

.report-placeholder-icon {
    font-size: 5rem;
    color: var(--primary-color);
    opacity: 0.3;
}

/* 隐藏元素 */
.hidden {
    display: none;
}

/* 加载动画 */
.loading-spinner {
    display: none;
}

/* 资料管理页面样式 */
.form-row {
    display: flex;
    gap: 10px;
}

.form-row select {
    flex: 1;
}

.form-row .btn {
    padding: 8px 15px;
}

.tab-container {
    margin-bottom: 20px;
    border-bottom: 2px solid #e0e0e0;
}

.full-width {
    width: 100%;
}

.mt-20 {
    margin-top: 20px;
}

.max-w-300 {
    max-width: 300px;
}

/* 视图切换样式 */
.view {
    display: none;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.view.active {
    display: block;
    opacity: 1;
}

/* ==================== 上传题目页面现代化样式 ==================== */

/* 上传容器 */
.upload-container {
    max-width: none;
    margin: 0 auto;
    padding: 2rem;
}

/* 上传头部 */
.upload-header {
    text-align: center;
    margin-bottom: 2.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 2px solid #e9ecef;
}

.upload-header h2 {
    font-size: 2.2rem;
    font-weight: 700;
    color: #2b2d42;
    margin: 0 0 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
}

.upload-subtitle {
    color: #6c757d;
    font-size: 1.1rem;
}

/* ==================== 答题页面现代化样式 ==================== */

/* 章节选择页面 */
#chapter-selection-view {
    max-width: 600px;
    margin: 2rem auto;
    padding: 2rem;
    background: #ffffff;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

#chapter-selection-view h2 {
    color: #2b2d42;
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    text-align: center;
}

#chapter-rank-banner {
    background: #f8f9fa;
    border: 1px solid #e9ecef;
    border-radius: 8px;
    padding: 1rem;
    margin-bottom: 1.5rem;
    text-align: center;
    font-weight: 500;
}

#current-subject-display {
    background: #e7f3ff;
    border: 1px solid #b3d9ff;
    border-radius: 8px;
    padding: 0.75rem;
    margin-bottom: 1.5rem;
    text-align: center;
    color: #0066cc;
    font-weight: 500;
}

#chapter-selection-view .form-group {
    margin-bottom: 1.25rem;
}

#chapter-selection-view .form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: #495057;
}

#chapter-selection-view .form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid #ced4da;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

#chapter-selection-view .form-control:focus {
    outline: none;
    border-color: #007bff;
    box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}

#chapter-selection-view .form-control:disabled {
    background-color: #f8f9fa;
    border-color: #dee2e6;
    cursor: not-allowed;
}

#start-quiz-btn {
    width: 100%;
    padding: 1rem;
    background: #007bff;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.1s ease;
    margin-top: 1rem;
}

#start-quiz-btn:hover:not(:disabled) {
    background: #0056b3;
}

#start-quiz-btn:active:not(:disabled) {
    transform: translateY(1px);
}

#start-quiz-btn:disabled {
    background: #6c757d;
    cursor: not-allowed;
}

#view-materials-btn {
    width: 100%;
    padding: 0.75rem;
    background: #28a745;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s ease;
    margin-top: 0.75rem;
}

#view-materials-btn:hover {
    background: #218838;
}

/* 答题页面 */
#quiz-view {
    max-width: 800px;
    margin: 2rem auto;
    padding: 2rem;
    background: #ffffff;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

#quiz-rank-banner {
    background: #f8f9fa;
    border: 1px solid #e9ecef;
    border-radius: 8px;
    padding: 0.75rem;
    margin-bottom: 1.5rem;
    text-align: center;
    font-weight: 500;
}

#question-title {
    color: #2b2d42;
    font-size: 1.5rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid #e9ecef;
}

#question-text {
    color: #495057;
    font-size: 1.1rem;
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

#question-image-container {
    margin: 1.5rem 0;
    text-align: center;
}

#question-image {
    max-width: 100%;
    max-height: 400px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

#html-animation-container {
    margin: 1.5rem 0;
    border: 1px solid #e9ecef;
    border-radius: 8px;
    overflow: hidden;
}

#html-animation-iframe {
    width: 100%;
    height: 400px;
    border: none;
}

/* 动画与视频控制 */
#animation-controls {
    background: #f8f9fa;
    border: 1px solid #e9ecef;
    border-radius: 8px;
    padding: 1rem;
    margin: 1.5rem 0;
}

#animation-controls button {
    background: #6c757d;
    color: white;
    border: none;
    border-radius: 6px;
    padding: 0.5rem 1rem;
    margin-right: 0.5rem;
    margin-bottom: 0.5rem;
    cursor: pointer;
    font-size: 0.9rem;
    transition: background-color 0.3s ease;
}

#animation-controls button:hover {
    background: #5a6268;
}

#video-preview {
    margin-top: 1rem;
}

#video-player {
    width: 100%;
    border-radius: 8px;
}

/* 题目类型指示器 */
.question-type-indicator {
    background: #e7f3ff;
    border: 1px solid #b3d9ff;
    border-radius: 6px;
    padding: 0.75rem;
    margin: 1.5rem 0;
    color: #0066cc;
    font-weight: 500;
}

/* 操作按钮 */
.actions {
    margin: 1.5rem 0;
}

.actions button {
    background: #007bff;
    color: white;
    border: none;
    border-radius: 6px;
    padding: 0.75rem 1.5rem;
    margin-right: 0.75rem;
    margin-bottom: 0.75rem;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    transition: background-color 0.3s ease, transform 0.1s ease;
}

.actions button:hover:not(:disabled) {
    background: #0056b3;
}

.actions button:active:not(:disabled) {
    transform: translateY(1px);
}

.actions button:disabled {
    background: #6c757d;
    cursor: not-allowed;
}

#mic-status {
    margin: 1rem 0;
    padding: 0.75rem;
    background: #f8f9fa;
    border: 1px solid #e9ecef;
    border-radius: 6px;
    font-size: 0.9rem;
}

/* 文本输入容器 */
.text-input-container {
    margin-top: 1.5rem;
}

.text-input-container h4 {
    color: #495057;
    margin-bottom: 0.75rem;
}

#text-answer {
    width: 100%;
    padding: 1rem;
    border: 2px solid #ced4da;
    border-radius: 8px;
    font-size: 1rem;
    line-height: 1.5;
    resize: vertical;
    min-height: 120px;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

#text-answer:focus {
    outline: none;
    border-color: #007bff;
    box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}

#submit-text-btn {
    margin-top: 0.75rem;
    background: #28a745;
}

#submit-text-btn:hover {
    background: #218838;
}

/* 参考答案容器 */
#teacher-answer-container {
    margin: 1.5rem 0;
}

#show-answer-btn {
    background: #ffc107;
    color: #212529;
    border: none;
    border-radius: 6px;
    padding: 0.75rem 1.5rem;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    transition: background-color 0.3s ease;
}

#show-answer-btn:hover {
    background: #e0a800;
}

#teacher-answer-box {
    background: #f8f9fa;
    border: 1px solid #e9ecef;
    border-radius: 8px;
    padding: 1.5rem;
    margin-top: 1rem;
    display: none;
}

#teacher-answer-box h5 {
    color: #2b2d42;
    margin-bottom: 0.75rem;
    font-size: 1.1rem;
}

#teacher-answer-text {
    color: #495057;
    line-height: 1.6;
    margin-bottom: 1rem;
}

#teacher-step-scores-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

#teacher-step-scores-list li {
    padding: 0.5rem 0;
    border-bottom: 1px solid #e9ecef;
}

#teacher-step-scores-list li:last-child {
    border-bottom: none;
}

/* 结果显示 */
.result {
    background: #f8f9fa;
    border: 1px solid #e9ecef;
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
}

.result h4 {
    color: #2b2d42;
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.result p {
    color: #495057;
    line-height: 1.6;
    margin-bottom: 1rem;
}

/* 答题历史 */
#answer-history-container {
    margin: 1.5rem 0;
}

.answer-history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #e9ecef;
    border-radius: 8px 8px 0 0;
    padding: 1rem;
}

.answer-history-header h4 {
    color: #2b2d42;
    margin: 0;
    font-size: 1.1rem;
}

#toggle-history-btn {
    background: none;
    border: none;
    color: #007bff;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.3s ease;
}

#toggle-history-btn:hover {
    color: #0056b3;
    text-decoration: underline;
}

#answer-history-content {
    background: #f8f9fa;
    border: 1px solid #e9ecef;
    border-top: none;
    border-radius: 0 0 8px 8px;
    padding: 1rem;
    max-height: 300px;
    overflow-y: auto;
}

#answer-history-list {
    margin: 0;
}

#no-history-message {
    text-align: center;
    color: #6c757d;
    padding: 2rem;
}

/* 导航按钮 */
.navigation-buttons {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 2px solid #e9ecef;
}

.navigation-buttons button {
    background: #6c757d;
    color: white;
    border: none;
    border-radius: 6px;
    padding: 0.75rem 1.5rem;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    transition: background-color 0.3s ease;
}

.navigation-buttons button:hover {
    background: #5a6268;
}

#prev-question-btn,
#next-question-btn {
    background: #007bff;
}

#prev-question-btn:hover,
#next-question-btn:hover {
    background: #0056b3;
}

/* 模态框样式 */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0,0,0,0.5);
    animation: fadeIn 0.3s ease;
}

.modal-content {
    background-color: #fefefe;
    margin: 5% auto;
    padding: 2rem;
    border: 1px solid #888;
    width: 80%;
    max-width: 800px;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    animation: slideIn 0.3s ease;
}

.close-btn {
    color: #aaa;
    position: absolute;
    right: 20px;
    top: 15px;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.3s ease;
}

.close-btn:hover {
    color: #333;
}

#student-detail-content {
    white-space: pre-wrap;
    line-height: 1.6;
    max-height: 60vh;
    overflow-y: auto;
    padding: 1rem;
    background: #f9f9f9;
    border-radius: 8px;
}

/* 动画效果 */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideIn {
    from { transform: translateY(-50px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

/* 响应式设计 */
@media (max-width: 768px) {
    #chapter-selection-view,
    #quiz-view {
        margin: 1rem;
        padding: 1.5rem;
    }
    
    .navigation-buttons {
        flex-direction: column;
        gap: 0.75rem;
        align-items: stretch;
    }
    
    .navigation-buttons button {
        width: 100%;
    }
    
    .actions button {
        display: block;
        width: 100%;
        margin-right: 0;
    }
    
    #animation-controls button {
        display: block;
        width: 100%;
        margin-right: 0;
    }
    
    .modal-content {
        width: 95%;
        margin: 10% auto;
        padding: 1.5rem;
    }
}

@media (max-width: 480px) {
    #chapter-selection-view,
    #quiz-view {
        margin: 0.5rem;
        padding: 1rem;
    }
    
    #question-title {
        font-size: 1.3rem;
    }
    
    #question-text {
        font-size: 1rem;
    }
    
    #html-animation-iframe {
        height: 300px;
    }
}

/* AI分析空状态样式 */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 3rem 2rem;
    text-align: center;
    background: #f8f9fa;
    border-radius: 12px;
    border: 2px dashed #dee2e6;
}

.empty-state .empty-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    opacity: 0.7;
}

.empty-state .empty-text {
    font-size: 1.1rem;
    color: #495057;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.empty-state .empty-hint {
    font-size: 0.9rem;
    color: #6c757d;
    max-width: 400px;
}
.upload-steps {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-bottom: 2.5rem;
    padding: 1.5rem;
    background: white;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}

.step-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.step-number {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: #e9ecef;
    color: #6c757d;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.2rem;
    transition: all 0.3s ease;
}

.step-item.active .step-number {
    background: linear-gradient(135deg, #4361ee, #3f37c9);
    color: white;
    box-shadow: 0 4px 12px rgba(67, 97, 238, 0.3);
}

.step-item.completed .step-number {
    background: linear-gradient(135deg, #20c997, #198754);
    color: white;
}

.step-label {
    font-size: 0.9rem;
    color: #6c757d;
    font-weight: 500;
}

.step-item.active .step-label {
    color: #4361ee;
    font-weight: 600;
}

.step-status {
    font-size: 0.75rem;
    color: #6c757d;
    margin-top: 0.25rem;
    transition: all 0.3s ease;
}

.step-item.active .step-status {
    color: #4361ee;
    font-weight: 600;
}

.step-item.completed .step-status {
    color: #20c997;
    font-weight: 600;
}

.step-progress {
    width: 100%;
    height: 3px;
    background: #e9ecef;
    border-radius: 2px;
    margin-top: 0.5rem;
    overflow: hidden;
}

.step-item.active .step-progress {
    background: linear-gradient(90deg, #4361ee, #4cc9f0);
    animation: progressPulse 2s ease-in-out infinite;
}

.step-item.completed .step-progress {
    background: linear-gradient(90deg, #20c997, #198754);
}

@keyframes progressPulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.7;
    }
}

.step-line {
    width: 80px;
    height: 3px;
    background: #e9ecef;
    margin: 0 1rem;
    border-radius: 2px;
    transition: all 0.3s ease;
}

.step-line.completed {
    background: linear-gradient(90deg, #20c997, #198754);
}

/* 步骤内容 */
.upload-step-content {
    display: none;
    animation: fadeInUp 0.4s ease;
}

.upload-step-content.active {
    display: block;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 表单区域 */
.form-section {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    margin-bottom: 1.5rem;
}

.section-title {
    font-size: 1.4rem;
    font-weight: 700;
    color: #2b2d42;
    margin-bottom: 1.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid #e9ecef;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* 现代化表单组 */
.form-row-modern {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.form-group-modern {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group-modern.full-width {
    grid-column: 1 / -1;
}

.form-group-modern label {
    font-weight: 600;
    color: #495057;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.95rem;
}

.label-icon {
    font-size: 1.2rem;
}

.ai-badge {
    background: linear-gradient(135deg, #4361ee, #4cc9f0);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-left: auto;
}

/* 输入框样式 */
.form-input-modern,
.form-select-modern,
.form-textarea-modern {
    padding: 0.875rem 1rem;
    border: 2px solid #e9ecef;
    border-radius: 10px;
    font-size: 1rem;
    transition: all 0.3s ease;
    outline: none;
    background: white;
}

.form-input-modern:focus,
.form-select-modern:focus,
.form-textarea-modern:focus {
    border-color: #4361ee;
    box-shadow: 0 0 0 4px rgba(67, 97, 238, 0.1);
}

.form-textarea-modern {
    resize: vertical;
    min-height: 120px;
    font-family: inherit;
    line-height: 1.6;
}

/* 输入组 */
.input-group-modern {
    display: flex;
    gap: 0.75rem;
}

.input-group-modern .form-select-modern {
    flex: 1;
}

/* 新章节和新课时输入组默认隐藏 */
#new-chapter-group,
#new-lesson-group {
    display: none;
}

/* 图标按钮 */
.btn-icon-modern {
    width: 48px;
    height: 48px;
    border: none;
    border-radius: 10px;
    background: linear-gradient(135deg, #4361ee, #3f37c9);
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    transition: all 0.3s ease;
}

.btn-icon-modern:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(67, 97, 238, 0.3);
}

/* AI辅助栏 */
.ai-assist-bar {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 0.75rem;
    padding: 0.75rem;
    background: #f8f9fa;
    border-radius: 10px;
}

.btn-ai-modern {
    padding: 0.625rem 1.25rem;
    border: none;
    border-radius: 8px;
    background: linear-gradient(135deg, #4361ee, #3f37c9);
    color: white;
    cursor: pointer;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
    position: relative;
}

.btn-ai-modern:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(67, 97, 238, 0.3);
}

.btn-ai-modern:disabled {
    background: #6c757d;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.loading-spinner {
    animation: spin 1s linear infinite;
    font-size: 1rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.ai-status {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: #6c757d;
    font-size: 0.9rem;
}

.ai-status .status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: #20c997;
    animation: pulse 2s ease-in-out infinite;
}

.ai-status.loading .status-dot {
    background: #ffc107;
    animation: pulse 1s ease-in-out infinite;
}

.ai-status.error .status-dot {
    background: #dc3545;
}

.ai-status.success .status-dot {
    background: #20c997;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.5;
        transform: scale(1.2);
    }
}

.ai-icon {
    font-size: 1.2rem;
}

.ai-status {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: #6c757d;
    font-size: 0.9rem;
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: #20c997;
}

/* 步骤分数容器 */
.step-scores-container {
    background: #f8f9fa;
    padding: 1rem;
    border-radius: 10px;
    margin-bottom: 1rem;
}

.btn-add-step {
    padding: 0.625rem 1.25rem;
    border: 2px dashed #4361ee;
    border-radius: 8px;
    background: transparent;
    color: #4361ee;
    cursor: pointer;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
}

.btn-add-step:hover {
    background: rgba(67, 97, 238, 0.1);
}

/* 步骤操作按钮 */
.step-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 2px solid #e9ecef;
}

.btn-next-step,
.btn-prev-step {
    padding: 0.875rem 1.75rem;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    font-weight: 600;
    font-size: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
}

.btn-next-step {
    background: linear-gradient(135deg, #4361ee, #3f37c9);
    color: white;
    margin-left: auto;
}

.btn-next-step:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(67, 97, 238, 0.3);
}

.btn-prev-step {
    background: #e9ecef;
    color: #495057;
}

.btn-prev-step:hover {
    background: #dee2e6;
}

/* 媒体卡片 */
.media-card {
    background: #f8f9fa;
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    border: 2px solid transparent;
    transition: all 0.3s ease;
}

.media-card:hover {
    border-color: #4361ee;
    box-shadow: 0 4px 12px rgba(67, 97, 238, 0.1);
}

.media-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.media-icon {
    font-size: 1.5rem;
}

.media-header h4 {
    margin: 0;
    font-size: 1.1rem;
    color: #2b2d42;
    flex: 1;
}

.optional-badge {
    background: #e9ecef;
    color: #6c757d;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
}

/* 粘贴框 */
.paste-box {
    border: 2px dashed #dee2e6;
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: white;
}

.paste-box:hover {
    border-color: #4361ee;
    background: rgba(67, 97, 238, 0.02);
}

.paste-icon {
    font-size: 2.5rem;
    margin-bottom: 0.75rem;
}

.paste-box p {
    margin: 0 0 0.5rem;
    color: #495057;
    font-weight: 500;
}

.paste-hint {
    color: #6c757d;
    font-size: 0.85rem;
}

/* 隐藏文件输入 */
.hidden-file-input {
    display: none;
}

/* 文件上传现代化 */
.file-upload-modern {
    margin-bottom: 1rem;
}

.file-upload-label {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 2rem;
    border: 2px dashed #dee2e6;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    background: white;
}

.file-upload-label:hover {
    border-color: #4361ee;
    background: rgba(67, 97, 238, 0.02);
}

.upload-icon {
    font-size: 2rem;
}

.upload-text {
    font-weight: 600;
    color: #495057;
}

.upload-hint {
    color: #6c757d;
    font-size: 0.85rem;
}

/* 预览容器 */
.preview-container {
    margin-top: 1rem;
}

.media-preview {
    max-width: 100%;
    max-height: 300px;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

/* 上传进度条 */
.upload-progress {
    margin-top: 1rem;
    margin-bottom: 0.75rem;
    height: 8px;
    background: #e9ecef;
    border-radius: 4px;
    overflow: hidden;
    position: relative;
    display: none;
}

.upload-progress.active {
    display: block;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, #4361ee, #4cc9f0);
    border-radius: 4px;
    width: 0%;
    transition: width 0.3s ease;
    animation: progressMove 1s ease-in-out infinite;
}

@keyframes progressMove {
    0% {
        background-position: 0% 50%;
    }
    100% {
        background-position: 100% 50%;
    }
}

.progress-text {
    position: absolute;
    top: 50%;
    right: 10px;
    transform: translateY(-50%);
    font-size: 0.75rem;
    font-weight: 600;
    color: #4361ee;
}

/* 视频类型选择器 */
.video-type-selector {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.radio-modern {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
}

.radio-modern input[type="radio"] {
    display: none;
}

.radio-custom {
    width: 20px;
    height: 20px;
    border: 2px solid #dee2e6;
    border-radius: 50%;
    position: relative;
    transition: all 0.3s ease;
}

.radio-modern input[type="radio"]:checked + .radio-custom {
    border-color: #4361ee;
}

.radio-modern input[type="radio"]:checked + .radio-custom::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 10px;
    height: 10px;
    background: #4361ee;
    border-radius: 50%;
}

.radio-label {
    color: #495057;
    font-weight: 500;
}

/* 视频区域 */
.video-section {
    margin-top: 1rem;
}

.video-section.hidden {
    display: none;
}

.video-preview-container {
    margin-top: 1rem;
}

.video-preview {
    max-width: 100%;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.video-preview-frame {
    width: 100%;
    height: 300px;
    border: none;
    border-radius: 8px;
}

/* 帮助文本 */
.help-text {
    display: block;
    margin-top: 0.75rem;
    color: #6c757d;
    font-size: 0.9rem;
    line-height: 1.6;
}

.help-icon {
    margin-right: 0.25rem;
}

/* 提交按钮 */
.btn-submit-modern {
    padding: 1rem 2.5rem;
    border: none;
    border-radius: 12px;
    background: linear-gradient(135deg, #20c997, #198754);
    color: white;
    cursor: pointer;
    font-weight: 700;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    transition: all 0.3s ease;
}

.btn-submit-modern:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(32, 201, 151, 0.3);
}

.submit-icon {
    font-size: 1.3rem;
}

/* 上传底部 */
.upload-footer {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 2px solid #e9ecef;
    text-align: center;
}

.btn-back-modern {
    padding: 0.875rem 1.75rem;
    border: 2px solid #dee2e6;
    border-radius: 10px;
    background: white;
    color: #6c757d;
    cursor: pointer;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
}

.btn-back-modern:hover {
    border-color: #4361ee;
    color: #4361ee;
    background: rgba(67, 97, 238, 0.05);
}

/* 学生详情模态框样式 */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0,0,0,0.4);
}

.modal-content {
    background-color: #fefefe;
    margin: 5% auto;
    padding: 20px;
    border: 1px solid #888;
    width: 80%;
    max-width: 800px;
    border-radius: 8px;
    position: relative;
}

.close-btn {
    color: #aaa;
    position: absolute;
    right: 20px;
    top: 10px;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
}

#student-detail-content {
    white-space: pre-wrap;
    line-height: 1.6;
    max-height: 60vh;
    overflow-y: auto;
    padding: 10px;
    background: #f9f9f9;
    border-radius: 4px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .upload-container {
        padding: 1rem;
    }
    
    .upload-header h2 {
        font-size: 1.6rem;
    }
    
    .upload-steps {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }
    
    .step-line {
        width: 3px;
        height: 30px;
        margin: 0;
    }
    
    .step-item {
        gap: 0.25rem;
    }
    
    .step-number {
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }
    
    .step-label {
        font-size: 0.8rem;
    }
    
    .step-status {
        font-size: 0.7rem;
    }
    
    .form-row-modern {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .form-section {
        padding: 1.25rem;
    }
    
    .form-group-modern {
        gap: 0.4rem;
    }
    
    .form-input-modern,
    .form-select-modern,
    .form-textarea-modern {
        padding: 0.75rem;
        font-size: 0.9rem;
    }
    
    .ai-assist-bar {
        flex-direction: column;
        align-items: stretch;
        gap: 0.75rem;
    }
    
    .btn-ai-modern {
        justify-content: center;
    }
    
    .step-actions {
        flex-direction: column;
        gap: 1rem;
    }
    
    .btn-next-step,
    .btn-prev-step,
    .btn-submit-modern {
        width: 100%;
        justify-content: center;
        padding: 0.875rem 1.5rem;
    }
    
    .video-type-selector {
        flex-direction: column;
        gap: 0.75rem;
    }
    
    .media-card {
        padding: 1rem;
    }
    
    .paste-box {
        padding: 1.5rem;
    }
    
    .file-upload-label {
        padding: 1.5rem;
    }
    
    .media-preview,
    .video-preview,
    .video-preview-frame {
        max-height: 200px;
    }
    
    .modal-content {
        width: 95%;
        margin: 10% auto;
        padding: 1.5rem;
    }
}

@media (max-width: 480px) {
    .upload-header h2 {
        font-size: 1.4rem;
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .upload-subtitle {
        font-size: 0.9rem;
    }
    
    .section-title {
        font-size: 1.2rem;
        flex-direction: column;
        align-items: flex-start;
        gap: 0.25rem;
    }
    
    .form-section {
        padding: 1rem;
    }
    
    .form-group-modern label {
        font-size: 0.85rem;
    }
    
    .btn-ai-modern {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
    }
    
    .btn-next-step,
    .btn-prev-step,
    .btn-submit-modern {
        padding: 0.75rem 1.25rem;
        font-size: 0.9rem;
    }
    
    .paste-box {
        padding: 1.25rem;
    }
    
    .paste-icon {
        font-size: 2rem;
    }
    
    .paste-box p {
        font-size: 0.85rem;
    }
    
    .upload-hint {
        font-size: 0.75rem;
    }
    
    .media-header h4 {
        font-size: 1rem;
    }
    
    .help-text {
        font-size: 0.8rem;
    }
}

/* 主头部样式 */
.main-header {
    background: linear-gradient(135deg, #4361ee, #3f37c9);
    color: white;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    padding: 2rem 0;
    margin-bottom: 2rem;
}

.header-container {
    max-width: none;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.header-brand {
    text-align: left;
}

.header-date {
    font-size: 1.1rem;
    font-weight: 500;
    opacity: 0.95;
    background: rgba(255,255,255,0.15);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    white-space: nowrap;
}

.brand-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin: 0;
    padding: 0;
    text-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.brand-subtitle {
    font-size: 1.2rem;
    margin: 0.5rem 0 0;
    opacity: 0.9;
    font-weight: 400;
}

/* 响应式头部 */
@media (max-width: 768px) {
    .main-header {
        padding: 1.5rem 0;
    }

    .brand-title {
        font-size: 2rem;
    }

    .brand-subtitle {
        font-size: 1rem;
    }

    .header-container {
        padding: 0 1rem;
        flex-direction: column;
        text-align: center;
    }

    .header-brand {
        text-align: center;
    }

    .header-date {
        font-size: 1rem;
    }
}

.saved-standard-select {
    max-width: 150px;
}

.evaluation-result-container {
    max-height: 600px;
}

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

body {
    background-color: #f5f5f5;
    color: #333;
    line-height: 1.6;
}

/* Utility Classes for fixing inline styles */
.scrollable-content {
    max-height: 200px;
    overflow-y: auto;
}

.select-max-width-150 {
    max-width: 150px;
}

.scrollable-result-container {
    max-height: 600px;
}

.notification-container-fixed {
    z-index: 10000;
}

/* 身份选择页面样式 */
#role-selection-view {
    text-align: center;
    padding: 2rem;
}

#role-selection-view h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: #2b2d42;
    margin-bottom: 3rem;
    text-align: center;
}

.role-buttons {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1.5rem;
    max-width: 1200px;
    margin: 0 auto 3rem;
    padding: 0 1rem;
    flex-wrap: wrap;
}

.role-buttons button {
    padding: 2rem 1.5rem;
    font-size: 1.4rem;
    font-weight: 600;
    border: 2px solid #e9ecef;
    border-radius: 20px;
    cursor: pointer;
    background: white;
    color: #2b2d42;
    box-shadow: 0 8px 24px rgba(0,0,0,0.08);
    transition: all 0.4s cubic-bezier(0.22, 1, 0.36, 1);
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    min-height: 160px;
    min-width: 250px;
    text-align: center;
    flex: 1;
    max-width: 300px;
}

.role-buttons button::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 6px;
    background: linear-gradient(90deg, #4361ee, #4cc9f0, #4361ee);
    background-size: 200% 100%;
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.4s ease;
}

.role-buttons button:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: 0 25px 50px rgba(67, 97, 238, 0.2);
    background: linear-gradient(135deg, #4361ee, #3f37c9);
    color: white;
    border-color: transparent;
}

.role-buttons button:hover::after {
    transform: scaleX(1);
    animation: gradientMove 2s linear infinite;
}

@keyframes gradientMove {
    0% {
        background-position: 0% 50%;
    }
    100% {
        background-position: 200% 50%;
    }
}

.role-buttons button:active {
    transform: translateY(-5px) scale(0.98);
    box-shadow: 0 15px 35px rgba(67, 97, 238, 0.15);
}

.role-link-container {
    margin-top: 3rem;
    text-align: center;
}

/* 响应式身份选择 */
@media (max-width: 768px) {
    #role-selection-view h1 {
        font-size: 2rem;
    }
    
    .role-buttons {
        flex-direction: column;
        align-items: stretch;
        gap: 1rem;
        padding: 0 0.5rem;
    }
    
    .role-buttons button {
        padding: 2rem 1.5rem;
        font-size: 1.2rem;
        min-height: 160px;
        min-width: auto;
        max-width: none;
    }
}

@media (max-width: 480px) {
    .role-buttons button {
        padding: 1.8rem 1.2rem;
        font-size: 1.1rem;
        min-height: 140px;
    }
}

.hidden {
    display: none !important;
}

.start-hidden {
    display: none;
}

/* Dashboard Styles */
.dashboard-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 15px;
    border-bottom: 2px solid #e0e0e0;
}

.dashboard-header h2 {
    font-size: 2rem;
    font-weight: 700;
    color: #2b2d42;
    margin: 0;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logout-btn {
    background: #f8f9fa;
    color: #6c757d;
    border: 1px solid #dee2e6;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
}

.logout-btn:hover {
    background: #e9ecef;
    color: #495057;
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.dashboard-content {
    max-width: none;
    margin: 0 auto;
}

.dashboard-section {
    margin-bottom: 30px;
    background: white;
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.dashboard-section:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.08);
}

.section-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: #2b2d42;
    margin-bottom: 1.5rem;
    position: relative;
    padding-left: 1rem;
    border-left: 5px solid #4361ee;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.dashboard-card-link, .dashboard-card-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 30px 20px;
    background: white;
    border-radius: 12px;
    text-decoration: none;
    color: #333;
    border: 1px solid #e9ecef;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    transition: all 0.3s cubic-bezier(0.22, 1, 0.36, 1);
    cursor: pointer;
    height: 100%;
    position: relative;
    overflow: hidden;
    text-align: center;
    min-height: 180px;
}

.dashboard-card-link:hover, .dashboard-card-btn:hover {
    box-shadow: 0 15px 35px rgba(0,0,0,0.1);
    transform: translateY(-8px);
    color: white;
    background: linear-gradient(135deg, #4361ee, #3f37c9);
    border-color: transparent;
}

.dashboard-card-link::before, .dashboard-card-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #4361ee, #4cc9f0);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s ease;
}

.dashboard-card-link:hover::before, .dashboard-card-btn:hover::before {
    transform: scaleX(1);
}

.card-icon {
    font-size: 3rem;
    margin-bottom: 15px;
    transition: transform 0.3s ease;
}

.dashboard-card-link:hover .card-icon, .dashboard-card-btn:hover .card-icon {
    transform: scale(1.1) rotate(5deg);
}

.card-title {
    font-weight: 600;
    font-size: 1.1rem;
    text-align: center;
    transition: all 0.3s ease;
    margin-bottom: 8px;
}

.card-description {
    font-size: 0.85rem;
    color: #6c757d;
    text-align: center;
    line-height: 1.4;
    transition: all 0.3s ease;
}

.dashboard-card-link:hover .card-description, .dashboard-card-btn:hover .card-description {
    color: rgba(255, 255, 255, 0.9);
}

/* 响应式仪表盘 */
@media (max-width: 768px) {
    .dashboard-header {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .dashboard-header h2 {
        font-size: 1.5rem;
    }
    
    .dashboard-section {
        padding: 1.5rem;
    }
    
    .dashboard-grid {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
        gap: 15px;
    }
    
    .dashboard-card-link, .dashboard-card-btn {
        padding: 20px 15px;
    }
    
    .card-icon {
        font-size: 2.5rem;
    }
    
    .card-title {
        font-size: 1rem;
    }
}

/* Student Dashboard Materials Styles */
.materials-container {
    background: #f8f9fa;
    border-radius: 12px;
    padding: 20px;
    margin-top: 20px;
}

.materials-filter {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    margin-bottom: 20px;
    align-items: flex-end;
}

.materials-filter label {
    font-weight: 500;
    color: #495057;
    margin-bottom: 5px;
}

.materials-filter select {
    flex: 1;
    min-width: 150px;
    padding: 10px;
    border: 1px solid #dee2e6;
    border-radius: 6px;
    font-size: 14px;
    background: white;
}

.materials-list {
    min-height: 200px;
}

.no-materials,
.loading-materials,
.error-materials {
    text-align: center;
    padding: 40px 20px;
    color: #6c757d;
    font-size: 16px;
}

.loading-materials {
    color: #007bff;
}

.error-materials {
    color: #dc3545;
}

.materials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

.material-item {
    background: white;
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    text-align: center;
}

.material-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
}

.material-icon {
    font-size: 3rem;
    margin-bottom: 15px;
}

.material-title {
    font-size: 16px;
    font-weight: 600;
    color: #2b2d42;
    margin-bottom: 15px;
    line-height: 1.4;
}

.view-material-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.view-material-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

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

.student-info span {
    font-size: 16px;
    font-weight: 600;
    color: #2b2d42;
}

/* Animations Container Styles */
.animations-container {
    margin-top: 20px;
}

.animation-category {
    margin-bottom: 30px;
}

.category-title {
    font-size: 18px;
    font-weight: 600;
    color: #2b2d42;
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 2px solid #e9ecef;
}

/* Leaderboard Styles */
.leaderboard-section {
    margin-top: 40px;
    background: white;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.leaderboard-section:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.08);
}

.leaderboard-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 25px;
    flex-wrap: wrap;
    gap: 15px;
    padding-bottom: 15px;
    border-bottom: 2px solid #e9ecef;
}

.leaderboard-header h2 {
    font-size: 1.8rem;
    font-weight: 700;
    color: #2b2d42;
    margin: 0;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.leaderboard-controls {
    display: flex;
    gap: 12px;
    align-items: center;
    flex-wrap: wrap;
}

.filter-select {
    padding: 8px 16px;
    border-radius: 8px;
    border: 1px solid #dee2e6;
    outline: none;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    background: white;
}

.filter-select:focus {
    border-color: #4361ee;
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.1);
}

.refresh-btn {
    padding: 8px 16px;
    border: 1px solid #dee2e6;
    border-radius: 8px;
    background: white;
    color: #6c757d;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.refresh-btn:hover {
    background: #f8f9fa;
    color: #495057;
    border-color: #adb5bd;
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

#leaderboard-container {
    min-height: 400px;
}

.loading-message {
    text-align: center;
    padding: 4rem;
    color: #6c757d;
    font-size: 1.1rem;
}

.error-message {
    text-align: center;
    padding: 4rem;
    color: #dc3545;
    font-size: 1.1rem;
}

/* 表单错误消息样式 */
.form-group-modern .error-message {
    padding: 0.5rem 0.75rem;
    margin-top: 0.5rem;
    background: #f8d7da;
    border: 1px solid #f5c6cb;
    border-radius: 6px;
    color: #721c24;
    font-size: 0.875rem;
    font-weight: 500;
    text-align: left;
    animation: fadeIn 0.3s ease;
}

/* 必填项标识 */
.required {
    color: #dc3545;
    font-weight: 700;
    margin-left: 0.25rem;
}

/* 表单元素错误状态 */
.form-input-modern.error,
.form-select-modern.error,
.form-textarea-modern.error {
    border-color: #dc3545;
    box-shadow: 0 0 0 4px rgba(220, 53, 69, 0.1);
}

/* 表单元素成功状态 */
.form-input-modern.success,
.form-select-modern.success,
.form-textarea-modern.success {
    border-color: #20c997;
    box-shadow: 0 0 0 4px rgba(32, 201, 151, 0.1);
}

.leaderboard-stats {
    background: #f8f9fa;
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 20px;
    text-align: center;
    font-size: 1.1rem;
    font-weight: 500;
    color: #495057;
}

#my-rank-card {
    background: linear-gradient(135deg, #4361ee, #4cc9f0);
    color: white;
    padding: 20px;
    border-radius: 12px;
    margin-bottom: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
}

#my-rank-card strong {
    font-size: 1.1rem;
}

#my-rank-text {
    font-size: 1.3rem;
    font-weight: 700;
}

#my-rank-card .refresh-btn {
    background: rgba(255,255,255,0.2);
    color: white;
    border-color: rgba(255,255,255,0.3);
}

#my-rank-card .refresh-btn:hover {
    background: rgba(255,255,255,0.3);
    border-color: rgba(255,255,255,0.4);
}

#my-progress-container {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 12px;
    margin-bottom: 20px;
}

#my-progress-content {
    min-height: 100px;
}

.leaderboard-table-container {
    overflow-x: auto;
    border-radius: 8px;
    border: 1px solid #e9ecef;
}

.leaderboard-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

.leaderboard-table th,
.leaderboard-table td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid #e9ecef;
}

.leaderboard-table th {
    background: #f8f9fa;
    font-weight: 600;
    color: #495057;
    white-space: nowrap;
}

.leaderboard-table tr:hover {
    background: #f8f9fa;
}

.leaderboard-table tr:nth-child(even) {
    background: #fafbfc;
}

/* 响应式排行榜 */
@media (max-width: 768px) {
    .leaderboard-section {
        padding: 20px;
    }
    
    .leaderboard-header {
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
    }
    
    .leaderboard-controls {
        justify-content: center;
    }
    
    .leaderboard-table {
        font-size: 0.8rem;
    }
    
    .leaderboard-table th,
    .leaderboard-table td {
        padding: 8px 12px;
    }
    
    #my-rank-card {
        flex-direction: column;
        align-items: stretch;
        text-align: center;
    }
}

/* Login Form Styles */
.login-container-margin {
    margin-top: 80px;
}

.login-error {
    color: #dc3545;
    margin-top: 10px;
    text-align: center;
    font-size: 0.9rem;
}

/* Animation */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes popIn {
    0% { opacity: 0; transform: scale(0.9) translateY(20px); }
    70% { opacity: 1; transform: scale(1.02) translateY(-2px); }
    100% { opacity: 1; transform: scale(1) translateY(0); }
}

.fade-in-item {
    animation: popIn 0.6s cubic-bezier(0.22, 1, 0.36, 1) forwards;
    opacity: 0;
}

/* New Login Page Styles */
.login-view-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 60vh;
}

.login-card {
    background: white;
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.05);
    width: 100%;
    max-width: 400px;
    text-align: center;
}

.login-card.register-mode {
    max-width: 500px;
}

.login-card h2 {
    margin-bottom: 2rem;
    color: #333;
    font-weight: 600;
}

.form-group {
    margin-bottom: 1.5rem;
    text-align: left;
}

.form-input {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s, box-shadow 0.3s;
    outline: none;
}

.form-input:focus {
    border-color: #4361ee;
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.1);
}

.password-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.toggle-password {
    position: absolute;
    right: 12px;
    background: none;
    border: none;
    cursor: pointer;
    color: #999;
    padding: 0;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    transition: color 0.3s;
}

.toggle-password:hover {
    color: #4361ee;
}

.login-btn {
    width: 100%;
    padding: 12px;
    background-color: #4361ee;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
    margin-top: 1rem;
}

.login-btn:hover {
    background-color: #3f37c9;
    transform: translateY(-1px);
}

.login-footer {
    margin-top: 1.5rem;
    font-size: 0.9rem;
    color: #666;
}

.login-footer a {
    color: #4361ee;
    text-decoration: none;
    font-weight: 500;
}

.login-footer a:hover {
    text-decoration: underline;
}

/* Update Back Button Style in Login Card */
.login-card .back-btn {
    margin-top: 1rem;
    background: transparent;
    color: #666;
    border: 1px solid #e0e0e0;
    width: 100%;
    padding: 10px;
    border-radius: 8px;
}

.login-card .back-btn:hover {
    background: #f5f5f5;
    color: #333;
}

/* Teacher Portal Specific Styles */
:root {
    --primary-color: #4361ee;
    --secondary-color: #3f37c9;
    --success-color: #4cc9f0;
    --danger-color: #f72585;
    --light-bg: #f8f9fa;
    --card-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
    --transition-speed: 0.3s;
}

/* Navbar Optimization */
.navbar {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color)) !important;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    padding: 1rem 0;
}
.navbar-brand {
    font-weight: 700;
    letter-spacing: 0.5px;
}

/* Card Container Styles */
.content-card {
    background: #fff;
    border-radius: 16px;
    box-shadow: var(--card-shadow);
    padding: 2rem;
    margin-bottom: 2rem;
    border: none;
    transition: transform var(--transition-speed);
}
.content-card:hover {
    transform: translateY(-2px);
}

/* Section Title Styles */
.section-title {
    font-weight: 700;
    color: #2b2d42;
    margin-bottom: 1.5rem;
    position: relative;
    padding-left: 1rem;
    border-left: 5px solid var(--primary-color);
}

/* Hero Section */
.hero-section {
    background: linear-gradient(120deg, #e0c3fc 0%, #8ec5fc 100%);
    color: #2b2d42;
    border-radius: 16px;
    padding: 3rem;
    margin-bottom: 2rem;
    position: relative;
    overflow: hidden;
    box-shadow: var(--card-shadow);
}
.hero-section::before {
    content: '';
    position: absolute;
    top: -50px;
    right: -50px;
    width: 200px;
    height: 200px;
    background: rgba(255,255,255,0.3);
    border-radius: 50%;
}

/* Form Control Optimization */
.form-label {
    font-weight: 600;
    color: #495057;
    margin-bottom: 0.5rem;
}
.form-control, .form-select {
    border-radius: 10px;
    padding: 0.75rem 1rem;
    border: 1px solid #dee2e6;
    transition: all var(--transition-speed);
}
.form-control:focus, .form-select:focus {
    box-shadow: 0 0 0 4px rgba(67, 97, 238, 0.15);
    border-color: var(--primary-color);
}

/* Button Optimization */
.btn {
    border-radius: 10px;
    padding: 0.6rem 1.5rem;
    font-weight: 600;
    letter-spacing: 0.3px;
    transition: all 0.2s ease;
}
.btn-primary {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}
.btn-lg {
    padding: 0.8rem 2rem;
    font-size: 1.1rem;
}
.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

/* Waveform Canvas */
#waveformCanvas {
    width: 100%;
    height: 80px;
    background-color: rgba(255,255,255,0.5);
    border-radius: 12px;
    margin-top: 15px;
    -webkit-backdrop-filter: blur(5px);
    backdrop-filter: blur(5px);
}

/* Utility Classes */
.input-group-rounded { border-radius: 10px; overflow: hidden; }
.input-file-import { max-width: 320px; }
.record-content-box { white-space: pre-wrap; min-height: 200px; }
.hero-text { opacity: 0.9; }

/* Recorded Text Display Area */
.recorded-text-content {
    background: #fff;
    border-radius: 12px;
    padding: 1.5rem;
    border: 1px solid #e9ecef;
    box-shadow: inset 0 2px 6px rgba(0,0,0,0.03);
    font-size: 1.05rem;
    line-height: 1.8;
    color: #495057;
    min-height: 150px;
    max-height: 400px;
    overflow-y: auto;
}

/* Sub-panel Styles */
.sub-panel {
    background: #f8f9fa;
    border-radius: 12px;
    padding: 1.5rem;
    border: 1px solid #e9ecef;
}

.gap-3 { gap: 1rem !important; }

/* Animations */
@keyframes successPop {
    0% { transform: scale(0.8) translate(-50%, -50%); opacity: 0; }
    50% { transform: scale(1.1) translate(-50%, -50%); opacity: 1; }
    100% { transform: scale(1) translate(-50%, -50%); opacity: 1; }
}
.save-success-animation {
    animation: successPop 0.5s ease-out forwards;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    transform-origin: top left;
    z-index: 9999;
    background: rgba(255, 255, 255, 0.98);
    padding: 30px 50px;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.2);
    text-align: center;
    display: none;
    border: 1px solid rgba(0,0,0,0.05);
}
.save-success-animation .icon-circle {
    width: 80px;
    height: 80px;
    background: #20c997;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    color: white;
    font-size: 40px;
    box-shadow: 0 10px 20px rgba(32, 201, 151, 0.3);
}
.save-success-animation span {
    font-size: 24px;
    font-weight: 700;
    color: #343a40;
    display: block;
}

/* Button Loading State */
.btn-loading {
    position: relative;
    color: transparent !important;
    pointer-events: none;
}
.btn-loading::after {
    content: "";
    position: absolute;
    width: 20px;
    height: 20px;
    top: 50%;
    left: 50%;
    margin-top: -10px;
    margin-left: -10px;
    border: 3px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 0.8s linear infinite;
}
@keyframes spin {
    to { transform: rotate(360deg); }
}

.pulse-red {
    animation: pulse-red-animation 2s infinite;
}
@keyframes pulse-red-animation {
    0% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.1); opacity: 0.7; }
    100% { transform: scale(1); opacity: 1; }
}

.btn-save-animate {
    transition: all 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
    overflow: hidden;
}
.btn-save-animate:active {
    transform: scale(0.95);
}

/* 系统说明链接样式 */
.system-guide-link {
    display: block;
    margin-top: 10px;
    color: #6c757d;
    text-decoration: none;
}

.system-guide-link:hover {
    color: #007bff;
    text-decoration: underline;
}

/* 学生表现页面样式 */
#student-performance-view {
    max-width: none;
    margin: 0 auto;
    padding: 2rem;
}

#student-performance-view h2 {
    font-size: 2rem;
    font-weight: 700;
    color: #2b2d42;
    margin-bottom: 2rem;
    text-align: center;
}

/* 标签页样式 */
.db-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    background: white;
    padding: 0.5rem;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.db-tab {
    padding: 0.75rem 1.5rem;
    border: none;
    background: transparent;
    color: #6c757d;
    cursor: pointer;
    border-radius: 8px;
    font-weight: 500;
    transition: all 0.3s ease;
    font-size: 1rem;
}

.db-tab:hover {
    background: #f8f9fa;
    color: #495057;
}

.db-tab.active {
    background: linear-gradient(135deg, #4361ee, #3f37c9);
    color: white;
    box-shadow: 0 2px 8px rgba(67, 97, 238, 0.3);
}

/* 数据库管理页面样式 */
#database-management-view {
    max-width: none;
    margin: 0 auto;
    padding: 2rem;
}

.db-header {
    text-align: center;
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 2px solid #e9ecef;
}

.db-header h2 {
    font-size: 2.2rem;
    font-weight: 700;
    color: #2b2d42;
    margin: 0 0 0.5rem;
}

.db-subtitle {
    color: #6c757d;
    font-size: 1.1rem;
    margin: 0;
}

/* 统计卡片样式 */
.db-stats-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    display: flex;
    align-items: center;
    gap: 1.5rem;
    transition: all 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.1);
}

.stat-icon {
    font-size: 3rem;
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #4361ee, #4cc9f0);
    border-radius: 16px;
    color: white;
}

.stat-info {
    flex: 1;
}

.stat-label {
    color: #6c757d;
    font-size: 1rem;
    margin-bottom: 0.25rem;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: #2b2d42;
}

/* 数据库标签页内容 */
.db-tab-content {
    display: none;
}

.db-tab-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* 数据库区域样式 */
.db-section {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    margin-bottom: 1.5rem;
}

/* 搜索栏样式 */
.db-search-bar {
    background: #f8f9fa;
    padding: 1.5rem;
    border-radius: 12px;
    margin-bottom: 1.5rem;
}

.db-search-bar input[type="text"],
.db-search-bar select {
    padding: 0.75rem 1rem;
    border: 1px solid #dee2e6;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
    outline: none;
}

.db-search-bar input[type="text"]:focus,
.db-search-bar select:focus {
    border-color: #4361ee;
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.1);
}

.filter-group {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    align-items: center;
    margin-top: 1rem;
}

.date-filter {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.date-filter label {
    color: #6c757d;
    font-weight: 500;
}

.date-filter input[type="date"] {
    padding: 0.5rem;
    border: 1px solid #dee2e6;
    border-radius: 6px;
    font-size: 0.9rem;
}

/* 操作按钮样式 */
.db-actions-modern {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.btn-primary,
.btn-success,
.btn-danger,
.btn-warning,
.btn-secondary,
.btn-large {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1rem;
}

.btn-primary {
    background: linear-gradient(135deg, #4361ee, #3f37c9);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(67, 97, 238, 0.3);
}

.btn-success {
    background: linear-gradient(135deg, #20c997, #198754);
    color: white;
}

.btn-success:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(32, 201, 151, 0.3);
}

.btn-danger {
    background: linear-gradient(135deg, #dc3545, #c82333);
    color: white;
}

.btn-danger:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(220, 53, 69, 0.3);
}

.btn-warning {
    background: linear-gradient(135deg, #ffc107, #e0a800);
    color: #212529;
}

.btn-warning:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(255, 193, 7, 0.3);
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(108, 117, 125, 0.3);
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.1rem;
}

.btn-icon {
    font-size: 1.2rem;
}

/* 表格样式 */
.table-info {
    background: #f8f9fa;
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    font-weight: 500;
    color: #495057;
}

.table-responsive {
    overflow-x: auto;
    border-radius: 8px;
    border: 1px solid #e9ecef;
}

.modern-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.95rem;
}

.modern-table th {
    background: linear-gradient(135deg, #4361ee, #3f37c9);
    color: white;
    padding: 1rem;
    text-align: left;
    font-weight: 600;
    white-space: nowrap;
}

.modern-table td {
    padding: 1rem;
    border-bottom: 1px solid #e9ecef;
}

.modern-table tbody tr:hover {
    background: #f8f9fa;
}

.modern-table tbody tr:nth-child(even) {
    background: #fafbfc;
}

.modern-table tbody tr:nth-child(even):hover {
    background: #f8f9fa;
}

/* 导入面板样式 */
#student-import-panel h4 {
    color: #2b2d42;
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

#student-import-panel p {
    color: #6c757d;
    margin-bottom: 1rem;
    line-height: 1.6;
}

#student-import-panel input[type="file"] {
    margin-bottom: 1rem;
    width: 100%;
}

#student-import-panel textarea {
    width: 100%;
    padding: 1rem;
    border: 1px solid #dee2e6;
    border-radius: 8px;
    margin-bottom: 1rem;
    resize: vertical;
    min-height: 150px;
    font-family: monospace;
}

/* 备份管理样式 */
.backup-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 1.5rem;
}

.backup-card {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.backup-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.1);
}

.backup-card.danger {
    border-color: #dc3545;
}

.backup-card h3 {
    color: #2b2d42;
    margin-bottom: 1rem;
    font-size: 1.4rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.backup-card p {
    color: #6c757d;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.backup-info {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid #e9ecef;
}

.backup-info small {
    color: #6c757d;
    font-size: 0.9rem;
}

/* 教学报告页面样式 */
#report-center-view {
    max-width: none;
    margin: 0 auto;
    padding: 2rem;
}

#report-center-view h2 {
    font-size: 2rem;
    font-weight: 700;
    color: #2b2d42;
    margin-bottom: 2rem;
    text-align: center;
}

#report-filters {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
    margin-bottom: 2rem;
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    align-items: center;
}

#report-filters label {
    color: #495057;
    font-weight: 500;
    margin-right: 0.5rem;
}

#report-filters select {
    padding: 0.75rem 1rem;
    border: 1px solid #dee2e6;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
}

#report-filters select:focus {
    border-color: #4361ee;
    box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.1);
}

/* 响应式设计 */
@media (max-width: 768px) {
    #student-performance-view,
    #database-management-view,
    #report-center-view {
        padding: 1rem;
    }
    
    .db-tabs {
        flex-direction: column;
    }
    
    .db-stats-cards {
        grid-template-columns: 1fr;
    }
    
    .stat-card {
        padding: 1.5rem;
    }
    
    .stat-icon {
        width: 60px;
        height: 60px;
        font-size: 2rem;
    }
    
    .stat-value {
        font-size: 1.5rem;
    }
    
    .db-section {
        padding: 1.5rem;
    }
    
    .db-search-bar {
        padding: 1rem;
    }
    
    .filter-group {
        flex-direction: column;
        align-items: stretch;
    }
    
    .db-actions-modern {
        flex-direction: column;
    }
    
    .backup-container {
        grid-template-columns: 1fr;
    }
    
    #report-filters {
        flex-direction: column;
        align-items: stretch;
    }
    
    .modern-table {
        font-size: 0.85rem;
    }
    
    .modern-table th,
    .modern-table td {
        padding: 0.75rem;
    }
}

/* 学生工作台教学资料库样式 */
.materials-list {
    margin-top: 20px;
}

.materials-list .no-materials {
    text-align: center;
    color: #666;
    padding: 40px;
    background: #f8f9fa;
    border-radius: 8px;
}

.materials-list .loading {
    text-align: center;
    color: #666;
    padding: 20px;
}

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

.material-card {
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    overflow: hidden;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.material-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
    border-color: #43e97b;
}

.material-header {
    padding: 20px;
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    color: white;
    position: relative;
}

.material-header.video {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

.material-header.animation {
    background: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
}

.material-type-icon {
    position: absolute;
    top: 15px;
    right: 15px;
    font-size: 24px;
}

.material-title {
    font-size: 1.3em;
    font-weight: bold;
    margin-bottom: 8px;
    padding-right: 40px;
}

.material-description {
    font-size: 0.9em;
    opacity: 0.9;
    line-height: 1.4;
}

.material-body {
    padding: 20px;
}

.material-meta {
    color: #666;
    font-size: 0.85em;
    margin-bottom: 15px;
}

.material-actions {
    display: flex;
    gap: 10px;
}

.material-actions .btn {
    background: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
    text-align: center;
}

.material-actions .btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(67, 233, 123, 0.4);
}

.material-actions .btn.primary {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

.material-actions .btn.primary:hover {
    box-shadow: 0 4px 12px rgba(79, 172, 254, 0.4);
}

/* 视频模态框样式 */
.video-modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.8);
}

.video-modal-content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: white;
    border-radius: 10px;
    padding: 20px;
    max-width: 90%;
    max-height: 90%;
}

.video-modal video {
    width: 100%;
    max-width: 800px;
    height: auto;
}

.close-modal {
    position: absolute;
    top: 10px;
    right: 15px;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    color: #aaa;
}

.close-modal:hover {
    color: #000;
}

/* 页脚样式 */
.main-footer {
    background: linear-gradient(135deg, #2b2d42 0%, #1a1a2e 100%);
    color: #e0e0e0;
    text-align: center;
    padding: 1.5rem 1rem;
    margin-top: 3rem;
    font-size: 0.9rem;
}

.main-footer .footer-container p {
    margin: 0.5rem 0;
}

.main-footer a {
    color: #64b5f6;
    text-decoration: none;
    transition: color 0.3s ease;
}

.main-footer a:hover {
    color: #90caf9;
    text-decoration: underline;
}