/**
 * 扩展功能样式文件
 * 功能：为社交功能、通知系统、用户追踪等提供样式
 * 作者：AI助手
 * 版本：1.0
 */

/* ==================== CSS变量定义 ==================== */
:root {
    /* 扩展功能颜色 */
    --extended-primary: #2196F3;
    --extended-primary-dark: #1976D2;
    --extended-primary-light: #BBDEFB;
    --extended-secondary: #FF9800;
    --extended-secondary-dark: #F57C00;
    --extended-secondary-light: #FFE0B2;
    
    /* 社交功能颜色 */
    --like-color: #E91E63;
    --like-color-active: #C2185B;
    --share-color: #4CAF50;
    --bookmark-color: #FF9800;
    --comment-color: #607D8B;
    
    /* 通知颜色 */
    --notification-info: #2196F3;
    --notification-success: #4CAF50;
    --notification-warning: #FF9800;
    --notification-error: #F44336;
    
    /* 间距和尺寸 */
    --extended-spacing-xs: 4px;
    --extended-spacing-sm: 8px;
    --extended-spacing-md: 16px;
    --extended-spacing-lg: 24px;
    --extended-spacing-xl: 32px;
    
    /* 圆角 */
    --extended-radius-sm: 4px;
    --extended-radius-md: 8px;
    --extended-radius-lg: 12px;
    --extended-radius-xl: 16px;
    
    /* 阴影 */
    --extended-shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.12);
    --extended-shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --extended-shadow-lg: 0 8px 25px rgba(0, 0, 0, 0.15);
    
    /* 过渡 */
    --extended-transition: all 0.2s ease;
    --extended-transition-slow: all 0.3s ease;
}

/* ==================== 社交功能按钮 ==================== */
.social-actions {
    display: flex;
    align-items: center;
    gap: var(--extended-spacing-md);
    margin: var(--extended-spacing-lg) 0;
    padding: var(--extended-spacing-md);
    border-top: 1px solid #eee;
    border-bottom: 1px solid #eee;
}

.social-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--extended-spacing-xs);
    padding: var(--extended-spacing-sm) var(--extended-spacing-md);
    border: 1px solid #ddd;
    border-radius: var(--extended-radius-md);
    background: white;
    color: #666;
    text-decoration: none;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--extended-transition);
    user-select: none;
}

.social-btn:hover {
    transform: translateY(-1px);
    box-shadow: var(--extended-shadow-sm);
}

.social-btn:active {
    transform: translateY(0);
}

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

/* 点赞按钮 */
.like-btn {
    border-color: var(--like-color);
    color: var(--like-color);
}

.like-btn:hover {
    background: var(--like-color);
    color: white;
}

.like-btn.liked,
.like-btn.active {
    background: var(--like-color);
    color: white;
    border-color: var(--like-color-active);
}

.like-btn .like-icon {
    width: 16px;
    height: 16px;
    transition: var(--extended-transition);
}

.like-btn.liked .like-icon {
    transform: scale(1.2);
}

/* 分享按钮 */
.share-btn {
    border-color: var(--share-color);
    color: var(--share-color);
}

.share-btn:hover {
    background: var(--share-color);
    color: white;
}

/* 书签按钮 */
.bookmark-btn {
    border-color: var(--bookmark-color);
    color: var(--bookmark-color);
}

.bookmark-btn:hover {
    background: var(--bookmark-color);
    color: white;
}

.bookmark-btn.bookmarked,
.bookmark-btn.active {
    background: var(--bookmark-color);
    color: white;
}

/* 分享下拉菜单 */
.share-dropdown {
    position: relative;
    display: inline-block;
}

.share-menu {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 200px;
    background: white;
    border: 1px solid #ddd;
    border-radius: var(--extended-radius-md);
    box-shadow: var(--extended-shadow-lg);
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--extended-transition);
}

.share-dropdown.active .share-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.share-menu-item {
    display: flex;
    align-items: center;
    gap: var(--extended-spacing-sm);
    padding: var(--extended-spacing-sm) var(--extended-spacing-md);
    color: #333;
    text-decoration: none;
    transition: var(--extended-transition);
}

.share-menu-item:hover {
    background: #f5f5f5;
}

.share-menu-item .share-icon {
    width: 20px;
    height: 20px;
}

/* ==================== 评论系统 ==================== */
.comments-section {
    margin: var(--extended-spacing-xl) 0;
    padding: var(--extended-spacing-lg);
    background: #fafafa;
    border-radius: var(--extended-radius-lg);
}

.comments-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--extended-spacing-lg);
    padding-bottom: var(--extended-spacing-md);
    border-bottom: 2px solid #eee;
}

.comments-title {
    font-size: 20px;
    font-weight: 600;
    color: #333;
}

.comments-count {
    color: #666;
    font-size: 14px;
}

/* 评论表单 */
.comment-form {
    margin-bottom: var(--extended-spacing-xl);
    padding: var(--extended-spacing-lg);
    background: white;
    border-radius: var(--extended-radius-md);
    box-shadow: var(--extended-shadow-sm);
}

.comment-form-group {
    margin-bottom: var(--extended-spacing-md);
}

.comment-form-label {
    display: block;
    margin-bottom: var(--extended-spacing-xs);
    font-weight: 500;
    color: #333;
}

.comment-form-input,
.comment-form-textarea {
    width: 100%;
    padding: var(--extended-spacing-sm) var(--extended-spacing-md);
    border: 1px solid #ddd;
    border-radius: var(--extended-radius-sm);
    font-size: 14px;
    transition: var(--extended-transition);
}

.comment-form-input:focus,
.comment-form-textarea:focus {
    outline: none;
    border-color: var(--extended-primary);
    box-shadow: 0 0 0 2px rgba(33, 150, 243, 0.1);
}

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

.comment-form-submit {
    background: var(--extended-primary);
    color: white;
    border: none;
    padding: var(--extended-spacing-sm) var(--extended-spacing-lg);
    border-radius: var(--extended-radius-sm);
    font-weight: 500;
    cursor: pointer;
    transition: var(--extended-transition);
}

.comment-form-submit:hover {
    background: var(--extended-primary-dark);
}

.comment-form-submit:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* 评论列表 */
.comments-list {
    space-y: var(--extended-spacing-lg);
}

.comment-item {
    background: white;
    border-radius: var(--extended-radius-md);
    padding: var(--extended-spacing-lg);
    box-shadow: var(--extended-shadow-sm);
    margin-bottom: var(--extended-spacing-md);
}

.comment-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--extended-spacing-sm);
}

.comment-author {
    font-weight: 600;
    color: #333;
}

.comment-date {
    color: #666;
    font-size: 12px;
}

.comment-content {
    color: #444;
    line-height: 1.6;
    margin-bottom: var(--extended-spacing-sm);
}

.comment-actions {
    display: flex;
    align-items: center;
    gap: var(--extended-spacing-md);
}

.comment-reply-btn {
    color: var(--extended-primary);
    background: none;
    border: none;
    font-size: 12px;
    cursor: pointer;
    transition: var(--extended-transition);
}

.comment-reply-btn:hover {
    text-decoration: underline;
}

/* 嵌套评论 */
.comment-replies {
    margin-top: var(--extended-spacing-lg);
    margin-left: var(--extended-spacing-xl);
    border-left: 2px solid #eee;
    padding-left: var(--extended-spacing-lg);
}

/* ==================== 通知系统 ==================== */
.notification-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 10000;
}

.notification-bell {
    position: relative;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: white;
    border: 1px solid #ddd;
    border-radius: 50%;
    cursor: pointer;
    transition: var(--extended-transition);
    box-shadow: var(--extended-shadow-sm);
}

.notification-bell:hover {
    background: #f5f5f5;
    transform: scale(1.05);
}

.notification-badge {
    position: absolute;
    top: -5px;
    right: -5px;
    min-width: 18px;
    height: 18px;
    background: var(--notification-error);
    color: white;
    border-radius: 9px;
    font-size: 11px;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0 4px;
}

.notification-dropdown {
    position: absolute;
    top: 100%;
    right: 0;
    width: 320px;
    max-height: 400px;
    background: white;
    border: 1px solid #ddd;
    border-radius: var(--extended-radius-lg);
    box-shadow: var(--extended-shadow-lg);
    overflow: hidden;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: var(--extended-transition);
}

.notification-container.active .notification-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.notification-header {
    padding: var(--extended-spacing-md);
    background: #f8f9fa;
    border-bottom: 1px solid #eee;
    font-weight: 600;
    color: #333;
}

.notification-list {
    max-height: 300px;
    overflow-y: auto;
}

.notification-item {
    padding: var(--extended-spacing-md);
    border-bottom: 1px solid #f0f0f0;
    transition: var(--extended-transition);
    cursor: pointer;
}

.notification-item:hover {
    background: #f8f9fa;
}

.notification-item:last-child {
    border-bottom: none;
}

.notification-title {
    font-weight: 600;
    color: #333;
    margin-bottom: var(--extended-spacing-xs);
}

.notification-message {
    color: #666;
    font-size: 14px;
    line-height: 1.4;
    margin-bottom: var(--extended-spacing-xs);
}

.notification-time {
    color: #999;
    font-size: 12px;
}

.notification-action {
    display: inline-block;
    margin-top: var(--extended-spacing-xs);
    color: var(--extended-primary);
    text-decoration: none;
    font-size: 12px;
    font-weight: 500;
}

.notification-action:hover {
    text-decoration: underline;
}

.notification-empty {
    padding: var(--extended-spacing-xl);
    text-align: center;
    color: #999;
    font-style: italic;
}

/* ==================== Toast通知 ==================== */
.toast {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: var(--extended-spacing-md) var(--extended-spacing-lg);
    border-radius: var(--extended-radius-md);
    color: white;
    font-weight: 500;
    z-index: 10001;
    box-shadow: var(--extended-shadow-lg);
    transition: var(--extended-transition);
}

.toast-info {
    background: var(--notification-info);
}

.toast-success {
    background: var(--notification-success);
}

.toast-warning {
    background: var(--notification-warning);
}

.toast-error {
    background: var(--notification-error);
}

/* ==================== 统计面板 ==================== */
.stats-panel {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--extended-spacing-lg);
    margin: var(--extended-spacing-xl) 0;
}

.stats-card {
    background: white;
    padding: var(--extended-spacing-lg);
    border-radius: var(--extended-radius-lg);
    box-shadow: var(--extended-shadow-sm);
    text-align: center;
    transition: var(--extended-transition);
}

.stats-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--extended-shadow-md);
}

.stats-number {
    font-size: 32px;
    font-weight: 700;
    color: var(--extended-primary);
    margin-bottom: var(--extended-spacing-xs);
}

.stats-label {
    color: #666;
    font-size: 14px;
    font-weight: 500;
}

.stats-change {
    margin-top: var(--extended-spacing-xs);
    font-size: 12px;
}

.stats-change.positive {
    color: var(--notification-success);
}

.stats-change.negative {
    color: var(--notification-error);
}

/* ==================== 搜索增强 ==================== */
.search-suggestions {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    border: 1px solid #ddd;
    border-top: none;
    border-radius: 0 0 var(--extended-radius-md) var(--extended-radius-md);
    box-shadow: var(--extended-shadow-md);
    z-index: 1000;
    max-height: 300px;
    overflow-y: auto;
}

.search-suggestion {
    padding: var(--extended-spacing-sm) var(--extended-spacing-md);
    cursor: pointer;
    transition: var(--extended-transition);
    border-bottom: 1px solid #f0f0f0;
}

.search-suggestion:hover,
.search-suggestion.active {
    background: #f8f9fa;
}

.search-suggestion:last-child {
    border-bottom: none;
}

.search-suggestion-text {
    font-weight: 500;
    color: #333;
}

.search-suggestion-meta {
    font-size: 12px;
    color: #666;
    margin-top: 2px;
}

/* ==================== 响应式设计 ==================== */
@media (max-width: 768px) {
    .social-actions {
        flex-wrap: wrap;
        gap: var(--extended-spacing-sm);
    }
    
    .social-btn {
        font-size: 12px;
        padding: var(--extended-spacing-xs) var(--extended-spacing-sm);
    }
    
    .notification-dropdown {
        width: 280px;
        right: -20px;
    }
    
    .share-menu {
        min-width: 160px;
    }
    
    .stats-panel {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
        gap: var(--extended-spacing-md);
    }
    
    .stats-number {
        font-size: 24px;
    }
    
    .comment-replies {
        margin-left: var(--extended-spacing-md);
        padding-left: var(--extended-spacing-md);
    }
}

@media (max-width: 414px) {
    .notification-container {
        top: 10px;
        right: 10px;
    }
    
    .notification-dropdown {
        width: calc(100vw - 40px);
        right: -10px;
    }
    
    .toast {
        top: 10px;
        right: 10px;
        left: 10px;
        width: auto;
    }
    
    .social-actions {
        padding: var(--extended-spacing-sm);
    }
    
    .comments-section {
        padding: var(--extended-spacing-md);
    }
    
    .comment-form {
        padding: var(--extended-spacing-md);
    }
}

@media (max-width: 390px) {
    .stats-panel {
        grid-template-columns: 1fr;
    }
    
    .social-actions {
        flex-direction: column;
        align-items: stretch;
    }
    
    .social-btn {
        justify-content: center;
    }
}

@media (max-width: 360px) {
    .notification-bell {
        width: 36px;
        height: 36px;
    }
    
    .notification-badge {
        min-width: 16px;
        height: 16px;
        font-size: 10px;
    }
    
    .comment-form-input,
    .comment-form-textarea {
        font-size: 16px; /* 防止iOS缩放 */
    }
}

/* ==================== 动画效果 ==================== */
@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
    100% {
        transform: scale(1);
    }
}

@keyframes slideInRight {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

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

.animate-pulse {
    animation: pulse 0.3s ease;
}

.animate-slide-in {
    animation: slideInRight 0.3s ease;
}

.animate-fade-in {
    animation: fadeInUp 0.3s ease;
}

/* ==================== 可访问性 ==================== */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* 高对比度模式支持 */
@media (prefers-contrast: high) {
    .social-btn {
        border-width: 2px;
    }
    
    .notification-item {
        border-bottom-width: 2px;
    }
}

/* 减少动画模式支持 */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* 深色模式支持 */
@media (prefers-color-scheme: dark) {
    :root {
        --extended-primary: #64B5F6;
        --extended-primary-dark: #42A5F5;
        --extended-primary-light: #E3F2FD;
    }
    
    .social-btn {
        background: #333;
        color: #fff;
        border-color: #555;
    }
    
    .notification-dropdown,
    .share-menu,
    .comment-form,
    .comment-item,
    .stats-card {
        background: #333;
        color: #fff;
        border-color: #555;
    }
    
    .comments-section {
        background: #2a2a2a;
    }
    
    .notification-header {
        background: #404040;
    }
}