/* ============================================
   小羊军团 - 全局样式表 (UX优化版)
   优化重点：视觉层次、微交互、响应式、无障碍
   ============================================ */

/* 基础变量与色彩系统 */
:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --primary-light: #dbeafe;
    --secondary-color: #0ea5e9;
    --accent-color: #f59e0b;
    --success-color: #10b981;
    --text-dark: #1f2937;
    --text-medium: #4b5563;
    --text-light: #6b7280;
    --bg-white: #ffffff;
    --bg-light: #f8fafc;
    --bg-card: #ffffff;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --max-width: 1200px;
    --header-height: 70px;
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* 暗色模式支持 */
@media (prefers-color-scheme: dark) {
    :root {
        --text-dark: #f9fafb;
        --text-medium: #d1d5db;
        --text-light: #9ca3af;
        --bg-light: #111827;
        --bg-card: #1f2937;
        --border-color: #374151;
    }
}

/* 减少动画偏好 */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* 基础重置 */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    line-height: 1.8;
    color: var(--text-dark);
    background-color: var(--bg-light);
    overflow-x: hidden;
}

/* 页面加载动画 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-on-scroll {
    opacity: 0;
    animation: fadeInUp 0.8s ease-out forwards;
}

/* 骨架屏加载动画 */
@keyframes shimmer {
    0% { background-position: -1000px 0; }
    100% { background-position: 1000px 0; }
}

.skeleton {
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 1000px 100%;
    animation: shimmer 2s infinite linear;
    border-radius: var(--radius-md);
}

/* 容器系统 */
.container {
    width: 92%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* 按钮系统 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: var(--radius-md);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all var(--transition-base);
    cursor: pointer;
    border: none;
    position: relative;
    overflow: hidden;
    letter-spacing: 0.02em;
}

.btn::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:active::after {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
}

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

.btn-secondary {
    background: var(--bg-white);
    color: var(--text-dark);
    border: 1.5px solid var(--border-color);
}

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

.btn-ghost {
    background: transparent;
    color: var(--primary-color);
    border: 1.5px solid var(--primary-light);
}

.btn-ghost:hover {
    background: var(--primary-light);
}

.btn-large {
    padding: 16px 32px;
    font-size: 1.1rem;
    border-radius: var(--radius-lg);
}

.btn-small {
    padding: 8px 16px;
    font-size: 0.85rem;
}

/* 标签系统 */
.tag {
    display: inline-flex;
    align-items: center;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.02em;
}

.tag-primary {
    background: var(--primary-light);
    color: var(--primary-color);
}

.tag-success {
    background: #d1fae5;
    color: var(--success-color);
}

.tag-warning {
    background: #fef3c7;
    color: #d97706;
}

.tag-danger {
    background: #fee2e2;
    color: #dc2626;
}

/* 头部导航 */
.site-header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: box-shadow var(--transition-base);
}

.site-header.scrolled {
    box-shadow: var(--shadow-md);
}

.site-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: var(--header-height);
}

.logo {
    font-size: 1.6rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
    cursor: pointer;
    transition: transform var(--transition-base);
}

.logo:hover {
    transform: scale(1.05);
}

/* 主导航 */
.main-nav ul {
    display: flex;
    list-style: none;
    gap: 8px;
    align-items: center;
}

.main-nav a {
    text-decoration: none;
    color: var(--text-medium);
    font-weight: 500;
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
    position: relative;
}

.main-nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: all var(--transition-base);
    transform: translateX(-50%);
    border-radius: 2px;
}

.main-nav a:hover,
.main-nav a.active {
    color: var(--primary-color);
    background: var(--primary-light);
}

.main-nav a:hover::after,
.main-nav a.active::after {
    width: 60%;
}

/* 汉堡菜单按钮 */
.mobile-menu-btn {
    display: none;
    flex-direction: column;
    justify-content: space-around;
    width: 28px;
    height: 24px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    z-index: 1100;
}

.mobile-menu-btn span {
    width: 100%;
    height: 2.5px;
    background: var(--text-dark);
    border-radius: 2px;
    transition: all 0.3s ease-in-out;
    transform-origin: center;
}

.mobile-menu-btn.active span:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}

.mobile-menu-btn.active span:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
}

.mobile-menu-btn.active span:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}

/* Hero 区域 */
.hero {
    position: relative;
    height: 85vh;
    min-height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    text-align: center;
    overflow: hidden;
    background: linear-gradient(135deg, #1e3a5f 0%, #2563eb 50%, #0ea5e9 100%);
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="rgba(255,255,255,0.05)" d="M0,96L48,112C96,128,192,160,288,186.7C384,213,480,235,576,213.3C672,192,768,128,864,128C960,128,1056,192,1152,208C1248,224,1344,192,1392,176L1440,160L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>');
    background-size: cover;
    background-position: bottom;
    opacity: 0.3;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.4;
    z-index: 0;
}

.hero .container {
    position: relative;
    z-index: 1;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
    animation: fadeInUp 1s ease-out;
}

.hero-content h1 {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 800;
    margin-bottom: 24px;
    line-height: 1.2;
    letter-spacing: -0.02em;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.hero-content p {
    font-size: clamp(1.1rem, 2.5vw, 1.4rem);
    margin-bottom: 40px;
    opacity: 0.95;
    font-weight: 400;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-cta {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* 脉冲动画 */
@keyframes pulse {
    0%, 100% { box-shadow: 0 0 0 0 rgba(37, 99, 235, 0.4); }
    50% { box-shadow: 0 0 0 15px rgba(37, 99, 235, 0); }
}

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

/* 滚动指示器 */
.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.85rem;
    animation: bounce 2s infinite;
    cursor: pointer;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
    40% { transform: translateX(-50%) translateY(-10px); }
    60% { transform: translateX(-50%) translateY(-5px); }
}

.scroll-indicator svg {
    width: 24px;
    height: 24px;
}

/* 区块标题 */
.section-title {
    font-size: clamp(1.8rem, 4vw, 2.5rem);
    font-weight: 700;
    text-align: center;
    margin-bottom: 16px;
    color: var(--text-dark);
    position: relative;
    display: inline-block;
    left: 50%;
    transform: translateX(-50%);
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 2px;
    margin: 12px auto 0;
}

.section-subtitle {
    text-align: center;
    color: var(--text-light);
    font-size: 1.1rem;
    margin-bottom: 48px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* 关于网格 */
.about-section {
    padding: 100px 0;
    background: var(--bg-light);
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 32px;
    margin-top: 48px;
}

.about-card {
    background: var(--bg-card);
    padding: 40px 32px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    text-align: center;
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.about-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transform: scaleX(0);
    transition: transform var(--transition-base);
}

.about-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.about-card:hover::before {
    transform: scaleX(1);
}

.about-card-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 24px;
    background: linear-gradient(135deg, var(--primary-light), #dbeafe);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    transition: transform var(--transition-base);
}

.about-card:hover .about-card-icon {
    transform: scale(1.1) rotate(5deg);
}

.about-card h3 {
    margin-bottom: 16px;
    color: var(--text-dark);
    font-size: 1.3rem;
    font-weight: 700;
}

.about-card p {
    color: var(--text-medium);
    line-height: 1.8;
    font-size: 0.95rem;
}

/* 数据统计栏 */
.stats-bar {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    padding: 60px 0;
    color: white;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 32px;
    text-align: center;
}

.stat-item h4 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 8px;
}

.stat-item p {
    opacity: 0.9;
    font-size: 1rem;
}

/* 新闻时间轴 */
.news-section {
    padding: 100px 0;
    background: var(--bg-white);
}

.news-list {
    list-style: none;
    max-width: 800px;
    margin: 48px auto 0;
    position: relative;
}

.news-list::before {
    content: '';
    position: absolute;
    left: 24px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(to bottom, var(--primary-color), var(--secondary-color));
}

.news-item {
    position: relative;
    padding-left: 64px;
    padding-bottom: 32px;
    transition: transform var(--transition-base);
}

.news-item:hover {
    transform: translateX(8px);
}

.news-item::before {
    content: '';
    position: absolute;
    left: 18px;
    top: 8px;
    width: 14px;
    height: 14px;
    background: var(--primary-color);
    border-radius: 50%;
    border: 3px solid var(--bg-white);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.news-item .date {
    display: inline-block;
    padding: 4px 12px;
    background: var(--primary-light);
    color: var(--primary-color);
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.news-item p {
    color: var(--text-medium);
    line-height: 1.7;
}

/* 列表页样式 */
.list-main {
    padding: 60px 0 100px;
}

.page-header {
    text-align: center;
    margin-bottom: 48px;
}

.page-header h1 {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-dark);
}

.page-header p {
    color: var(--text-light);
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto;
}

/* 筛选标签 */
.filter-bar {
    display: flex;
    gap: 12px;
    justify-content: center;
    margin-bottom: 48px;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 10px 20px;
    border: 1.5px solid var(--border-color);
    background: var(--bg-white);
    border-radius: 30px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-medium);
    transition: all var(--transition-fast);
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
}

/* 活动网格 */
.activity-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 32px;
}

.activity-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
    position: relative;
    display: flex;
    flex-direction: column;
}

.activity-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.activity-card-image {
    position: relative;
    overflow: hidden;
    aspect-ratio: 16/10;
}

.activity-card-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.activity-card:hover .activity-card-image img {
    transform: scale(1.08);
}

.activity-card-badge {
    position: absolute;
    top: 16px;
    left: 16px;
    z-index: 2;
}

.activity-card-price {
    position: absolute;
    bottom: 16px;
    right: 16px;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    color: white;
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    font-weight: 700;
    font-size: 1.1rem;
    z-index: 2;
}

.card-content {
    padding: 24px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.card-content h3 {
    margin-bottom: 12px;
    color: var(--text-dark);
    font-size: 1.2rem;
    font-weight: 700;
    line-height: 1.4;
}

.card-content p {
    color: var(--text-medium);
    font-size: 0.95rem;
    line-height: 1.7;
    margin-bottom: 20px;
    flex: 1;
}

.card-meta {
    display: flex;
    gap: 16px;
    margin-bottom: 20px;
    font-size: 0.85rem;
    color: var(--text-light);
}

.card-meta span {
    display: flex;
    align-items: center;
    gap: 4px;
}

.card-actions {
    display: flex;
    gap: 12px;
    margin-top: auto;
}

.card-actions .btn {
    flex: 1;
}

/* 详情页样式 */
.detail-main {
    padding: 40px 0 80px;
}

.detail-layout {
    display: grid;
    grid-template-columns: 1fr 380px;
    gap: 40px;
    align-items: start;
}

/* 阅读进度条 */
.reading-progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    z-index: 1001;
    transition: width 0.1s linear;
    box-shadow: 0 0 10px rgba(37, 99, 235, 0.3);
}

/* 详情头部 */
.activity-detail {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    overflow: hidden;
}

.activity-header {
    padding: 40px;
    border-bottom: 1px solid var(--border-color);
}

.activity-header h1 {
    font-size: clamp(1.8rem, 4vw, 2.5rem);
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-dark);
    line-height: 1.3;
}

.activity-meta-bar {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
    align-items: center;
}

.activity-meta-bar .meta-item {
    display: flex;
    align-items: center;
    gap: 6px;
    color: var(--text-light);
    font-size: 0.95rem;
}

/* 图片画廊 */
.gallery {
    position: relative;
    margin: 0;
    background: #000;
}

.gallery-main {
    width: 100%;
    height: 450px;
    object-fit: cover;
    display: block;
}

.gallery-thumbs {
    display: flex;
    gap: 8px;
    padding: 16px;
    background: var(--bg-dark);
    overflow-x: auto;
}

.gallery-thumbs img {
    width: 80px;
    height: 60px;
    object-fit: cover;
    border-radius: var(--radius-sm);
    cursor: pointer;
    opacity: 0.6;
    transition: all var(--transition-fast);
    border: 2px solid transparent;
}

.gallery-thumbs img:hover,
.gallery-thumbs img.active {
    opacity: 1;
    border-color: var(--primary-color);
}

/* 内容区域 */
.activity-body {
    padding: 40px;
}

.activity-body h2 {
    font-size: 1.5rem;
    font-weight: 700;
    margin: 40px 0 20px;
    color: var(--text-dark);
    padding-bottom: 12px;
    border-bottom: 2px solid var(--border-color);
    position: relative;
}

.activity-body h2::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 60px;
    height: 2px;
    background: var(--primary-color);
}

.activity-body h2:first-child {
    margin-top: 0;
}

.activity-body ul,
.activity-body ol {
    padding-left: 24px;
    margin-bottom: 24px;
}

.activity-body li {
    margin-bottom: 12px;
    line-height: 1.8;
    color: var(--text-medium);
}

.activity-body strong {
    color: var(--text-dark);
    font-weight: 600;
}

.activity-body p {
    margin-bottom: 20px;
    line-height: 1.9;
    color: var(--text-medium);
    font-size: 1.05rem;
}

/* 锚点导航 */
.toc-nav {
    position: sticky;
    top: 90px;
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    padding: 24px;
    margin-bottom: 24px;
}

.toc-nav h4 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-dark);
}

.toc-nav ul {
    list-style: none;
}

.toc-nav li {
    margin-bottom: 8px;
}

.toc-nav a {
    text-decoration: none;
    color: var(--text-medium);
    font-size: 0.9rem;
    display: block;
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
    border-left: 3px solid transparent;
}

.toc-nav a:hover,
.toc-nav a.active {
    background: var(--primary-light);
    color: var(--primary-color);
    border-left-color: var(--primary-color);
}

/* 侧边信息栏 */
.sidebar-card {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    padding: 24px;
    margin-bottom: 24px;
}

.sidebar-card h4 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--text-dark);
    display: flex;
    align-items: center;
    gap: 8px;
}

.price-tag {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.price-note {
    font-size: 0.85rem;
    color: var(--text-light);
    margin-bottom: 24px;
}

.info-list {
    list-style: none;
}

.info-list li {
    display: flex;
    justify-content: space-between;
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.95rem;
}

.info-list li:last-child {
    border-bottom: none;
}

.info-list .label {
    color: var(--text-light);
}

.info-list .value {
    font-weight: 600;
    color: var(--text-dark);
}

/* 分享按钮 */
.share-buttons {
    display: flex;
    gap: 12px;
    margin-top: 20px;
}

.share-btn {
    flex: 1;
    padding: 10px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    background: var(--bg-white);
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-medium);
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
}

.share-btn:hover {
    background: var(--bg-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

/* 页脚 */
.site-footer {
    background: linear-gradient(135deg, #1f2937, #111827);
    color: #9ca3af;
    padding: 60px 0 30px;
    margin-top: 100px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h4 {
    color: white;
    font-size: 1.1rem;
    margin-bottom: 20px;
    font-weight: 600;
}

.footer-section ul {
    list-style: none;
}

.footer-section li {
    margin-bottom: 12px;
}

.footer-section a {
    color: #9ca3af;
    text-decoration: none;
    transition: color var(--transition-fast);
    font-size: 0.95rem;
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: 30px;
    text-align: center;
    font-size: 0.9rem;
}

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-lg);
    z-index: 999;
    border: none;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--primary-hover);
    transform: translateY(-4px);
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .detail-layout {
        grid-template-columns: 1fr;
    }

    .sidebar {
        order: -1;
    }

    .toc-nav {
        position: relative;
        top: 0;
    }
}

@media (max-width: 768px) {
    :root {
        --header-height: 60px;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .main-nav {
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(10px);
        padding: 20px;
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-base);
    }

    .main-nav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .main-nav ul {
        flex-direction: column;
        gap: 4px;
    }

    .main-nav a {
        display: block;
        padding: 12px 16px;
        width: 100%;
    }

    .hero {
        height: 70vh;
        min-height: 500px;
    }

    .hero-cta {
        flex-direction: column;
        align-items: center;
    }

    .hero-cta .btn {
        width: 100%;
        max-width: 280px;
    }

    .about-grid,
    .activity-grid {
        grid-template-columns: 1fr;
        gap: 24px;
    }

    .activity-header,
    .activity-body {
        padding: 24px;
    }

    .gallery-main {
        height: 250px;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }

    .filter-bar {
        overflow-x: auto;
        flex-wrap: nowrap;
        padding-bottom: 8px;
        -webkit-overflow-scrolling: touch;
    }

    .filter-btn {
        white-space: nowrap;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 32px;
    }
}

@media (max-width: 480px) {
    .container {
        width: 95%;
        padding: 0 12px;
    }

    .hero-content h1 {
        font-size: 2rem;
    }

    .section-title {
        font-size: 1.6rem;
    }

    .about-card,
    .activity-card {
        padding: 24px 20px;
    }

    .card-actions {
        flex-direction: column;
    }

    .card-actions .btn {
        width: 100%;
    }

    .activity-meta-bar {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }
}

/* 打印样式 */
@media print {
    .site-header,
    .site-footer,
    .back-to-top,
    .reading-progress,
    .sidebar {
        display: none !important;
    }

    .activity-detail {
        box-shadow: none;
        border: 1px solid #ddd;
    }
}