:root {
    /* 浅色主题变量 */
    --bg-color: #f6f8fa;
    --card-bg: #ffffffcc;
    --text-color: #222;
    --primary-color: #6366f1;
    --border-color: #e5e7eb;
    --secondary-bg: #f9fafb;
    --shadow-color: rgba(0, 0, 0, 0.05);
    --hover-color: rgba(99, 102, 241, 0.1);
    --danger-color: #ef4444;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --accent-color: #8b5cf6;
}

.dark-mode {
    /* 深色主题变量 */
    --bg-color: #121212;
    --card-bg: #1e1e1ecc;
    --text-color: #e4e4e7;
    --primary-color: #818cf8;
    --border-color: #333;
    --secondary-bg: #1a1a1a;
    --shadow-color: rgba(0, 0, 0, 0.2);
    --hover-color: rgba(129, 140, 248, 0.15);
    --danger-color: #f87171;
    --success-color: #34d399;
    --warning-color: #fbbf24;
    --accent-color: #a78bfa;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    transition: background-color 0.3s, border-color 0.3s, color 0.3s;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    padding: 20px;
    line-height: 1.5;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

/* 玻璃拟态效果 */
.glass-card {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: 12px;
    border: 1px solid var(--border-color);
    box-shadow: 0 8px 32px var(--shadow-color);
    overflow: hidden;
}

/* 头部样式 */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    margin-bottom: 20px;
    flex-wrap: wrap;
    gap: 16px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo h1 {
    font-size: 1.8rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.logo-icon {
    font-size: 2rem;
    color: var(--primary-color);
}

/* 控制按钮区域 */
.controls {
    display: flex;
    gap: 12px;
    align-items: center;
    flex-wrap: wrap;
}

/* 按钮统一风格 - 修复样式异常 */
.btn {
    padding: 10px 20px;
    border-radius: 999px;
    border: none;
    font-weight: 600;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: all 0.2s ease;
    font-size: 0.9rem;
    text-decoration: none;
    white-space: nowrap;
    line-height: 1.2;
    min-height: 40px;
    justify-content: center;
    user-select: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
}

.btn:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.btn:active {
    transform: translateY(0);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
}

.btn-secondary {
    background: linear-gradient(135deg, #6b7280, #9ca3af);
    color: white;
}

.btn-danger {
    background: linear-gradient(135deg, var(--danger-color), #dc2626);
    color: white;
}

.btn-success {
    background: linear-gradient(135deg, var(--success-color), #059669);
    color: white;
}

.btn-warning {
    background: linear-gradient(135deg, var(--warning-color), #d97706);
    color: white;
}

.btn-icon {
    padding: 10px;
    width: 40px;
    height: 40px;
    justify-content: center;
}

/* 主题切换按钮 */
.theme-toggle {
    background: var(--secondary-bg);
    color: var(--text-color);
}

/* 面包屑导航 */
.breadcrumb {
    display: flex;
    align-items: center;
    padding: 16px 20px;
    background: var(--secondary-bg);
    border-radius: 12px;
    margin-bottom: 20px;
    flex-wrap: wrap;
    gap: 8px;
}

.breadcrumb-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 12px;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
}

.breadcrumb-item:hover {
    background: var(--hover-color);
    transform: translateY(-1px);
}

.breadcrumb-item.active {
    color: var(--primary-color);
    font-weight: 700;
}

.breadcrumb-separator {
    color: #9ca3af;
    font-size: 0.9rem;
}

/* 主内容区域 */
.main-content {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 20px;
}

@media (max-width: 768px) {
    .main-content {
        grid-template-columns: 1fr;
    }
}

/* 侧边栏 - 分类管理 */
.sidebar {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.section-title {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 8px;
}

/* 文件夹树样式 */
.folder-tree {
    list-style: none;
    padding-left: 0;
}

.folder-item {
    padding: 12px 16px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 6px;
    transition: all 0.2s;
}

.folder-item:hover {
    background: var(--hover-color);
}

.folder-item.active {
    background: var(--hover-color);
    color: var(--primary-color);
    font-weight: 600;
}

.folder-icon {
    font-size: 1.1rem;
}

.folder-children {
    margin-left: 24px;
    border-left: 1px dashed var(--border-color);
    padding-left: 12px;
}

/* 文件夹操作按钮 */
.folder-actions {
    display: flex;
    gap: 6px;
    margin-left: auto;
    opacity: 0;
    transition: opacity 0.2s;
}

.folder-item:hover .folder-actions {
    opacity: 1;
}

.folder-action-btn {
    background: none;
    border: none;
    color: #6b7280;
    cursor: pointer;
    padding: 4px;
    border-radius: 4px;
    font-size: 0.8rem;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 24px;
    min-height: 24px;
}

.folder-action-btn:hover {
    background: var(--hover-color);
    color: var(--primary-color);
}

/* 搜索框 */
.search-box {
    position: relative;
    margin-bottom: 20px;
}

.search-input {
    width: 100%;
    padding: 14px 16px 14px 48px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    color: var(--text-color);
    font-size: 1rem;
    transition: all 0.3s;
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.search-icon {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: #9ca3af;
}

/* 任务列表 */
.tasks-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

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

.task-item {
    padding: 18px;
    border-radius: 12px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    cursor: pointer;
    transition: all 0.2s;
}

.task-item:hover {
    border-color: var(--primary-color);
    box-shadow: 0 4px 12px var(--shadow-color);
    transform: translateY(-2px);
}

.task-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: 12px;
}

.task-title {
    font-weight: 600;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    gap: 10px;
    word-break: break-word;
}

.task-title.completed {
    text-decoration: line-through;
    opacity: 0.7;
}

.task-checkbox {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    border: 2px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    flex-shrink: 0;
    transition: all 0.2s;
}

.task-checkbox.checked {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

.task-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-top: 12px;
    flex-wrap: wrap;
}

.task-priority {
    padding: 4px 10px;
    border-radius: 999px;
    font-size: 0.8rem;
    font-weight: 600;
}

.priority-high {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger-color);
}

.priority-medium {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning-color);
}

.priority-low {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success-color);
}

.task-due-date {
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: 0.9rem;
    color: #6b7280;
}

.task-tags {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
}

.tag {
    padding: 4px 10px;
    border-radius: 999px;
    font-size: 0.8rem;
    background: var(--secondary-bg);
    word-break: break-word;
}

.task-description {
    margin-top: 12px;
    color: #6b7280;
    font-size: 0.95rem;
    line-height: 1.5;
    word-break: break-word;
}

.task-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 16px;
}

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

.task-action-btn {
    background: none;
    border: none;
    color: #6b7280;
    cursor: pointer;
    padding: 6px;
    border-radius: 6px;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 28px;
    min-height: 28px;
}

.task-action-btn:hover {
    background: var(--hover-color);
    color: var(--primary-color);
}

/* 进度条 */
.progress-bar {
    height: 6px;
    border-radius: 999px;
    background: var(--secondary-bg);
    overflow: hidden;
    margin-top: 12px;
    position: relative;
}

.progress-fill {
    height: 100%;
    border-radius: 999px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    transition: width 0.3s ease;
}

.progress-text {
    font-size: 0.8rem;
    color: #6b7280;
    margin-top: 4px;
}

/* 任务详情页面 - 修复布局异常 */
/* .task-detail-container {
    display: flex;
    flex-direction: column;
    gap: 24px;
    min-height: 0;
    width: 100%;
}

.task-detail-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 20px;
    gap: 20px;
    flex-wrap: wrap;
}

.task-detail-title-section {
    flex: 1;
    min-width: 0;
    margin-right: 20px;
}

.task-detail-title-section h2 {
    word-break: break-word;
    line-height: 1.4;
    margin-bottom: 12px;
    font-size: 1.8rem;
    font-weight: 700;
} */

#detailTaskMeta {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    align-items: center;
}

.task-detail-actions {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    align-items: flex-start;
    flex-shrink: 0;
}

.task-detail-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.info-card {
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    min-width: 0;
    word-wrap: break-word;
    overflow-wrap: break-word;
    height: 100%;
    box-sizing: border-box;
}

.info-label {
    font-size: 0.85rem;
    color: #6b7280;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.info-value {
    font-size: 1rem;
    font-weight: 500;
    word-break: break-word;
    color: var(--text-color);
}

.subtasks-section {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.subtask-item {
    padding: 16px 20px;
    border-radius: 12px;
    background: var(--secondary-bg);
    display: flex;
    align-items: center;
    gap: 16px;
    transition: all 0.2s ease;
    position: relative;
    border: 1px solid transparent;
}

.subtask-item:hover {
    background: var(--hover-color);
    border-color: var(--border-color);
    transform: translateY(-1px);
}

.subtask-title {
    flex: 1;
    min-width: 0;
    word-break: break-word;
    font-size: 0.95rem;
    line-height: 1.4;
}

.subtask-title.completed {
    text-decoration: line-through;
    opacity: 0.7;
}

.subtask-checkbox {
    width: 22px;
    height: 22px;
    border-radius: 6px;
    border: 2px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    flex-shrink: 0;
    transition: all 0.2s ease;
    background: var(--card-bg);
}

.subtask-checkbox:hover {
    border-color: var(--primary-color);
    transform: scale(1.05);
}

.subtask-checkbox.checked {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

.subtask-checkbox.checked:hover {
    background: var(--accent-color);
    border-color: var(--accent-color);
}

.subtask-actions {
    display: flex;
    gap: 8px;
    flex-shrink: 0;
}

/* 模态框 */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.2s;
}

.modal.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: var(--card-bg);
    border-radius: 16px;
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    padding: 24px;
    transform: scale(0.9);
    transition: transform 0.2s;
}

.modal.active .modal-content {
    transform: scale(1);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.modal-title {
    font-size: 1.3rem;
    font-weight: 700;
}

.close-modal {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: #6b7280;
    cursor: pointer;
    padding: 4px;
    border-radius: 6px;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 32px;
    min-height: 32px;
}

.close-modal:hover {
    background: var(--hover-color);
    color: var(--danger-color);
}

.form-group {
    margin-bottom: 20px;
}

.form-label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
}

.form-input, .form-textarea, .form-select {
    width: 100%;
    padding: 12px 16px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background: var(--secondary-bg);
    color: var(--text-color);
    font-size: 1rem;
    transition: all 0.2s;
}

.form-input:focus, .form-textarea:focus, .form-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-textarea {
    min-height: 100px;
    resize: vertical;
}

.form-actions {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    margin-top: 24px;
}

/* 拖拽样式 */
.dragging {
    opacity: 0.5;
    border: 2px dashed var(--primary-color);
}

.drag-over {
    border-top: 2px solid var(--primary-color);
}

/* 空状态 */
.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: #6b7280;
}

.empty-icon {
    font-size: 3rem;
    color: #d1d5db;
    margin-bottom: 16px;
}

/* 返回按钮 */
.back-button {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    background: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-color);
    cursor: pointer;
    transition: all 0.2s;
    margin-bottom: 20px;
    width: fit-content;
}

.back-button:hover {
    background: var(--hover-color);
    border-color: var(--primary-color);
}

/* 导入导出样式 */
.data-actions {
    display: flex;
    gap: 12px;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    flex-wrap: wrap;
}

/* 标签输入样式 */
.tags-input {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    padding: 8px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--secondary-bg);
    align-items: center;
}

.tag-input {
    border: none;
    background: transparent;
    color: var(--text-color);
    flex-grow: 1;
    min-width: 100px;
    padding: 8px;
}

.tag-input:focus {
    outline: none;
}

/* 确认对话框 */
.confirm-dialog {
    max-width: 400px;
}

.confirm-message {
    margin-bottom: 20px;
    line-height: 1.6;
}

.confirm-actions {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
}

/* 任务详情页面修复 */
.task-detail-container {
    min-height: 0;
}

.task-detail-info {
    align-items: stretch;
}

.info-card {
    flex: 1;
    min-width: 0;
    word-wrap: break-word;
}

/* 子任务布局修复 */
.subtask-item {
    position: relative;
}

.subtask-checkbox {
    flex-shrink: 0;
}

/* 响应式表格布局 */
@media (max-width: 480px) {
    .task-detail-info {
        display: flex;
        flex-direction: column;
    }
    
    .info-card {
        width: 100%;
    }
}

/* 移动端优化 */
@media (max-width: 768px) {
    .header {
        flex-direction: column;
        align-items: flex-start;
        gap: 16px;
    }
    
    .controls {
        width: 100%;
        justify-content: space-between;
        flex-wrap: wrap;
    }
    
    .btn {
        padding: 10px 16px;
        font-size: 0.85rem;
        min-height: 36px;
    }
    
    .task-header {
        flex-direction: column;
        gap: 10px;
    }
    
    .task-actions {
        margin-top: 10px;
    }
    
    .task-detail-info {
        grid-template-columns: 1fr;
    }
    
    .task-detail-header {
        flex-direction: column;
        align-items: stretch;
    }
    
    .task-detail-actions {
        justify-content: center;
    }
    
    .subtask-item {
        flex-direction: column;
        align-items: stretch;
        gap: 8px;
    }
    
    .subtask-title {
        min-width: auto;
        width: 100%;
    }
    
    .subtask-actions {
        justify-content: flex-end;
        width: 100%;
    }
    
    .modal-content {
        width: 95%;
        padding: 20px;
    }
    
    .form-actions {
        flex-direction: column;
    }
    
    .form-actions .btn {
        width: 100%;
    }
    
    .data-actions {
        flex-direction: column;
    }
    
    .data-actions .btn {
        width: 100%;
    }
}

/* 超小屏幕优化 */
@media (max-width: 480px) {
    body {
        padding: 10px;
    }
    
    .header {
        padding: 15px;
    }
    
    .logo h1 {
        font-size: 1.5rem;
    }
    
    .controls {
        gap: 8px;
    }
    
    .btn {
        padding: 8px 12px;
        font-size: 0.8rem;
    }
    
    .btn-icon {
        width: 36px;
        height: 36px;
        padding: 8px;
    }
    
    .breadcrumb {
        padding: 12px 15px;
    }
    
    .glass-card {
        padding: 15px !important;
    }
    
    .task-item {
        padding: 15px;
    }
    
    .modal-content {
        padding: 15px;
    }
    
    .task-detail-header {
        gap: 15px;
    }
    
    .task-detail-actions {
        gap: 8px;
    }
    
    .info-card {
        padding: 15px;
    }
}

/* 任务详情描述修复 */
#detailTaskDescription {
    overflow-wrap: break-word;
    word-wrap: break-word;
    hyphens: auto;
    line-height: 1.6;
}

#detailTaskDescription h3 {
    margin-bottom: 12px;
    font-size: 1.1rem;
    word-break: break-word;
}

#detailTaskDescription p {
    margin: 0;
    word-break: break-word;
}

/* 子任务输入框布局修复 */
.form-group[style*="display: flex"] {
    display: flex !important;
    gap: 10px;
    align-items: flex-end;
}

.form-group[style*="display: flex"] .form-input {
    flex: 1;
    margin: 0;
}

.form-group[style*="display: flex"] .btn {
    margin: 0;
    white-space: nowrap;
}

/* 确保按钮文本不溢出 */
.btn span {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    max-width: 100px;
}

/* 响应式按钮文本 */
@media (max-width: 480px) {
    .btn span {
        max-width: 60px;
    }
    
    .task-detail-actions .btn span {
        max-width: 40px;
    }
}

/* 文件夹任务计数样式修复 */
.folder-task-count {
    margin-left: auto;
    font-size: 0.8rem;
    color: #6b7280;
    white-space: nowrap;
}

/* 标签样式增强 */
.tag {
    display: inline-flex;
    align-items: center;
    max-width: 100%;
}

.tag button {
    margin-left: 4px;
    padding: 2px;
    font-size: 0.7rem;
}

/* 进度条容器 */
.progress-bar {
    position: relative;
    background: var(--secondary-bg);
}

/* 任务计数样式 */
.task-count {
    font-size: 0.9rem;
    color: #6b7280;
    font-weight: normal;
    margin-left: 8px;
}

/* 主内容区域布局 */
.main-content {
    display: flex;
    gap: 20px;
    flex: 1;
    min-height: 0; /* 防止flex item溢出 */
}

/* 侧边栏和任务区域 */
.sidebar {
    width: 280px;
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    gap: 20px;
    max-height: calc(100vh - 160px); /* 根据实际情况调整 */
    overflow-y: auto;
}

.tasks-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
    max-height: calc(100vh - 160px);
    overflow-y: auto;
}

.task-detail-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
    max-height: calc(100vh - 160px);
    overflow-y: auto;
}

/* 响应式调整 */
@media (max-width: 1024px) {
    .sidebar {
        width: 240px;
    }
}

@media (max-width: 768px) {
    .main-content {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        max-height: none;
    }
    
    .tasks-section,
    .task-detail-container {
        max-height: none;
    }
}

/* 底部样式 */
.footer {
    margin-top: 20px;
    padding: 16px 24px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    font-size: 0.9rem;
    color: var(--text-color);
    opacity: 0.8;
    transition: opacity 0.3s ease;
}

.footer:hover {
    opacity: 1;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
}

.footer-left, .footer-right {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
}

.footer-link {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease;
    cursor: pointer;
}

.footer-link:hover {
    color: var(--accent-color);
    text-decoration: underline;
}

/* 关于我们弹窗 */
.about-content {
    padding: 20px 0;
}

.about-logo {
    text-align: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
}

.logo-icon.large {
    width: 80px;
    height: 80px;
    margin: 0 auto 16px;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    color: white;
}

.about-logo h3 {
    font-size: 2rem;
    margin: 0 0 8px;
    color: var(--text-color);
}

.version {
    color: #6b7280;
    font-size: 0.9rem;
    margin: 0;
}

.about-description {
    line-height: 1.6;
    color: var(--text-color);
}

.features {
    margin: 24px 0;
    padding: 20px;
    background: var(--secondary-bg);
    border-radius: 12px;
}

.features h4 {
    margin: 0 0 16px;
    color: var(--text-color);
    display: flex;
    align-items: center;
    gap: 8px;
}

.features h4 i {
    color: var(--accent-color);
}

.features ul {
    margin: 0;
    padding-left: 20px;
    list-style: none;
}

.features li {
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.features li i {
    color: var(--success-color);
    font-size: 0.9rem;
}

.contact-info {
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
}

.contact-info h4 {
    margin: 0 0 16px;
    color: var(--text-color);
    display: flex;
    align-items: center;
    gap: 8px;
}

.contact-links {
    display: flex;
    gap: 12px;
    margin-top: 16px;
    flex-wrap: wrap;
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-color);
    padding: 8px 16px;
    border-radius: 6px;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: all 0.3s ease;
}

.btn-outline:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    text-decoration: none;
}

/* 隐私政策和使用条款弹窗 */
.privacy-content,
.terms-content {
    padding: 20px 0;
    max-height: 400px;
    overflow-y: auto;
}

.privacy-section,
.terms-section {
    margin-bottom: 24px;
}

.privacy-section:last-child,
.terms-section:last-child {
    margin-bottom: 0;
}

.privacy-section h3,
.terms-section h3 {
    color: var(--text-color);
    margin: 0 0 12px;
    font-size: 1.2rem;
}

.privacy-section p,
.terms-section p {
    margin: 0 0 12px;
    line-height: 1.6;
}

.privacy-section ul,
.terms-section ul {
    margin: 12px 0;
    padding-left: 20px;
}

.privacy-section li,
.terms-section li {
    margin-bottom: 6px;
    line-height: 1.5;
}

/* 弹窗页脚 */
.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    padding: 20px 0 0;
    margin-top: 20px;
    border-top: 1px solid var(--border-color);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .footer-content {
        flex-direction: column;
        text-align: center;
        gap: 12px;
    }
    
    .footer-left, .footer-right {
        justify-content: center;
    }
    
    .contact-links {
        justify-content: center;
    }
    
    .modal-footer {
        flex-direction: column;
    }
    
    .modal-footer .btn {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .footer {
        padding: 12px 16px;
        font-size: 0.8rem;
    }
    
    .footer-left, .footer-right {
        gap: 12px;
    }
    
    .features {
        padding: 16px;
    }
}