/* ============================================
   51漫画 - 现代化响应式样式表
   SEO优化，性能优化，可访问性优化
   ============================================ */

/* CSS变量定义 */
:root {
    --primary-color: #FF4D4F;
    --secondary-color: #FFC107;
    --dark-color: #1D2129;
    --light-color: #F2F3F5;
    --text-dark: #1D2129;
    --text-light: #86909C;
    --text-lighter: #C9CDD4;
    --bg-color: #ffffff;
    --bg-light: #F2F3F5;
    --border-color: #E5E6EB;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 5px 20px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
    --max-width: 1200px;
}

/* 重置样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-color);
    overflow-x: hidden;
}

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

/* 导航栏 */
.main-header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
    transition: var(--transition);
}

.navbar {
    padding: 15px 0;
}

.nav-wrapper {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 20px;
}

.logo-section {
    display: flex;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--text-dark);
    font-size: 24px;
    font-weight: 700;
    transition: var(--transition);
}

.logo:hover {
    color: var(--primary-color);
}

.logo-icon {
    font-size: 32px;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-color);
    border-radius: 8px;
    color: white;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
    flex-wrap: wrap;
}

.nav-link {
    color: var(--text-dark);
    text-decoration: none;
    font-weight: 500;
    padding: 8px 16px;
    border-radius: 8px;
    transition: var(--transition);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
    background-color: rgba(255, 77, 79, 0.1);
}

.nav-search {
    position: relative;
    flex: 1;
    max-width: 300px;
}

.nav-search form {
    display: flex;
    align-items: center;
    position: relative;
}

.nav-search input {
    width: 100%;
    padding: 10px 45px 10px 15px;
    border: 2px solid var(--border-color);
    border-radius: 25px;
    font-size: 14px;
    transition: var(--transition);
}

.nav-search input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(255, 77, 79, 0.1);
}

.nav-search button {
    position: absolute;
    right: 5px;
    padding: 8px 12px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 20px;
    cursor: pointer;
    transition: var(--transition);
}

.nav-search button:hover {
    background: #ff3336;
    transform: scale(1.05);
}

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

.btn-register,
.btn-login {
    padding: 10px 20px;
    border-radius: 25px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    font-size: 14px;
    border: none;
}

.btn-register {
    background: var(--primary-color);
    color: white;
}

.btn-register:hover {
    background: #ff3336;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

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

.btn-login:hover {
    background: rgba(255, 77, 79, 0.1);
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    border-radius: 3px;
    transition: var(--transition);
}

/* 英雄区域 */
.hero-section {
    padding: 100px 0 80px;
    background: linear-gradient(135deg, var(--primary-color) 0%, #ff6b6b 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.hero-section::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 0 100 100"><circle cx="50" cy="50" r="2" fill="rgba(255,255,255,0.1)"/></svg>') repeat;
    opacity: 0.3;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 48px;
    font-weight: 800;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 20px;
    margin-bottom: 40px;
    opacity: 0.95;
    line-height: 1.6;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
}

.btn-primary,
.btn-secondary {
    padding: 15px 40px;
    border-radius: 30px;
    font-weight: 700;
    font-size: 16px;
    text-decoration: none;
    transition: var(--transition);
    display: inline-block;
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: white;
    color: var(--primary-color);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.4);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-3px);
}

.hero-image {
    position: relative;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

.hero-image img {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 20px;
}

/* 区块标题 */
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 40px;
    flex-wrap: wrap;
    gap: 20px;
}

.section-title {
    font-size: 36px;
    font-weight: 700;
    color: var(--text-dark);
}

.section-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

.section-link:hover {
    transform: translateX(5px);
}

/* 分类区域 */
.categories-section {
    padding: 80px 0;
    background: var(--bg-light);
}

.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
}

.category-card {
    background: white;
    padding: 30px 20px;
    border-radius: 15px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: var(--transition);
    text-decoration: none;
    color: var(--text-dark);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
}

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

.category-icon {
    font-size: 48px;
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-light);
    border-radius: 50%;
    transition: var(--transition);
}

.category-card:hover .category-icon {
    transform: scale(1.1);
}

.category-name {
    font-size: 18px;
    font-weight: 600;
}

/* 热门漫画区域 */
.hot-section {
    padding: 80px 0;
}

.filter-buttons {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 10px 20px;
    border: 2px solid var(--border-color);
    background: white;
    border-radius: 25px;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 600;
    font-size: 14px;
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.comics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 25px;
}

.comic-card {
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    text-decoration: none;
    color: var(--text-dark);
    display: flex;
    flex-direction: column;
}

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

.comic-image {
    position: relative;
    width: 100%;
    height: 280px;
    overflow: hidden;
    background: var(--bg-light);
}

.comic-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.comic-card:hover .comic-image img {
    transform: scale(1.1);
}

.comic-badge {
    position: absolute;
    top: 10px;
    left: 10px;
    padding: 5px 12px;
    border-radius: 15px;
    font-size: 12px;
    font-weight: 600;
    color: white;
    z-index: 2;
}

.comic-badge.hot {
    background: var(--primary-color);
}

.comic-badge.new {
    background: #10b981;
}

.comic-badge.completed {
    background: #3b82f6;
}

.comic-update {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(to top, rgba(29, 33, 41, 0.8), transparent);
    padding: 15px 10px 10px;
    color: white;
    font-size: 12px;
}

.comic-info {
    padding: 15px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.comic-info h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 8px;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.comic-meta {
    display: flex;
    gap: 8px;
    font-size: 14px;
    color: var(--text-light);
    margin-bottom: 10px;
    flex-wrap: wrap;
}

.comic-rating {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: auto;
}

.stars {
    display: flex;
    align-items: center;
    gap: 2px;
}

.star {
    color: #fbbf24;
    font-size: 14px;
}

.star.half {
    color: #fbbf24;
    opacity: 0.5;
}

.star.empty {
    color: var(--text-lighter);
}

.rating-text {
    margin-left: 5px;
    font-size: 14px;
    color: var(--text-light);
    font-weight: 600;
}

.comic-views {
    font-size: 12px;
    color: var(--text-light);
}

/* 最新上架区域 */
.new-section {
    padding: 80px 0;
    background: var(--bg-light);
}

.new-comics-scroll {
    display: flex;
    gap: 20px;
    overflow-x: auto;
    padding-bottom: 20px;
    scroll-behavior: smooth;
    -webkit-overflow-scrolling: touch;
}

.new-comics-scroll::-webkit-scrollbar {
    height: 8px;
}

.new-comics-scroll::-webkit-scrollbar-track {
    background: var(--bg-light);
    border-radius: 4px;
}

.new-comics-scroll::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 4px;
}

.new-comic-card {
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    text-decoration: none;
    color: var(--text-dark);
    display: flex;
    flex-direction: column;
    min-width: 200px;
    flex-shrink: 0;
}

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

.new-comic-card .comic-image {
    height: 300px;
}

/* 排行榜区域 */
.ranking-section {
    padding: 80px 0;
}

.ranking-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 30px;
}

.ranking-list {
    background: white;
    border-radius: 15px;
    box-shadow: var(--shadow);
    overflow: hidden;
}

.ranking-list-title {
    background: var(--primary-color);
    color: white;
    padding: 20px;
    font-size: 24px;
    font-weight: 700;
    margin: 0;
}

.ranking-item {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
    transition: var(--transition);
}

.ranking-item:hover {
    background: var(--bg-light);
}

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

.rank-number {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    font-weight: 700;
    font-size: 18px;
    flex-shrink: 0;
}

.ranking-item:first-child .rank-number {
    background: var(--primary-color);
    color: white;
}

.ranking-item:not(:first-child) .rank-number {
    background: var(--bg-light);
    color: var(--text-dark);
}

.ranking-cover {
    width: 60px;
    height: 80px;
    object-fit: cover;
    border-radius: 8px;
    flex-shrink: 0;
}

.ranking-info {
    flex: 1;
}

.ranking-info h4 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 5px;
}

.ranking-meta {
    display: flex;
    gap: 8px;
    font-size: 14px;
    color: var(--text-light);
    margin-bottom: 8px;
    flex-wrap: wrap;
}

.ranking-stats {
    display: flex;
    gap: 10px;
    align-items: center;
    font-size: 14px;
}

.rank-change {
    font-weight: 700;
    font-size: 14px;
    flex-shrink: 0;
}

.rank-change.up {
    color: #10b981;
}

.rank-change.down {
    color: var(--primary-color);
}

/* 会员推广区域 */
.membership-section {
    padding: 80px 0;
    background: linear-gradient(135deg, var(--primary-color) 0%, #ff6b6b 100%);
    color: white;
}

.membership-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.membership-text h2 {
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 15px;
}

.membership-text > p {
    font-size: 18px;
    margin-bottom: 30px;
    opacity: 0.95;
}

.membership-features {
    list-style: none;
    margin-bottom: 40px;
}

.membership-features li {
    padding: 12px 0;
    font-size: 16px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.membership-buttons {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
}

.membership-image {
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

.membership-image img {
    width: 100%;
    height: auto;
    display: block;
}

/* APP下载区域 */
.app-section {
    padding: 80px 0;
    background: white;
}

.app-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.app-image {
    border-radius: 20px;
    overflow: hidden;
    box-shadow: var(--shadow-hover);
}

.app-image img {
    width: 100%;
    height: auto;
    display: block;
}

.app-text h2 {
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 15px;
    color: var(--text-dark);
}

.app-text > p {
    font-size: 18px;
    color: var(--text-light);
    margin-bottom: 30px;
    line-height: 1.6;
}

.app-buttons {
    display: flex;
    gap: 15px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.app-download-btn {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 15px 25px;
    background: var(--dark-color);
    color: white;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 600;
}

.app-download-btn:hover {
    background: #2a2e36;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.app-icon {
    font-size: 32px;
}

.app-label {
    font-size: 12px;
    opacity: 0.8;
}

.app-platform {
    font-size: 16px;
    font-weight: 700;
}

.qr-code-section {
    display: flex;
    align-items: center;
    gap: 20px;
}

.qr-code {
    width: 100px;
    height: 100px;
    background: var(--bg-light);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.qr-code img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.qr-text p {
    font-size: 14px;
    color: var(--text-light);
    margin-bottom: 5px;
}

/* 页脚 */
.footer {
    background: var(--dark-color);
    color: white;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1.5fr;
    gap: 50px;
    margin-bottom: 40px;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.footer-logo .logo-icon {
    width: 40px;
    height: 40px;
}

.footer-logo .logo-text {
    font-size: 24px;
    font-weight: 700;
}

.footer-brand p {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.8;
    font-size: 14px;
}

.social-links {
    display: flex;
    gap: 12px;
    margin-top: 5px;
}

.social-links a {
    width: 44px;
    height: 44px;
    background: rgba(255, 255, 255, 0.15);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    text-decoration: none;
    transition: var(--transition);
    font-size: 16px;
    font-weight: 500;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.social-links a:hover {
    background: rgba(255, 77, 79, 0.3);
    border-color: var(--primary-color);
    transform: translateY(-3px);
    box-shadow: 0 4px 12px rgba(255, 77, 79, 0.3);
}

.footer-links {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
}

.link-group h4 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 20px;
}

.link-group ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.link-group a,
.link-group li {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
    font-size: 14px;
}

.link-group a:hover {
    color: var(--primary-color);
    transform: translateX(5px);
}

.contact-info {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.contact-info p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 14px;
    margin-bottom: 8px;
    line-height: 1.6;
}

.contact-info p:last-child {
    margin-bottom: 0;
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
    font-size: 14px;
}

.footer-bottom p {
    margin-bottom: 15px;
}

.footer-policies {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.footer-policies a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
}

.footer-policies a:hover {
    color: var(--primary-color);
}

/* 回到顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 24px;
    cursor: pointer;
    box-shadow: var(--shadow-hover);
    transition: var(--transition);
    opacity: 0;
    visibility: hidden;
    z-index: 1000;
}

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

.back-to-top:hover {
    background: #ff3336;
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(255, 77, 79, 0.4);
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .hero-content,
    .membership-content,
    .app-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .hero-image,
    .membership-image,
    .app-image {
        order: -1;
    }
    
    .ranking-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr 1fr;
        gap: 30px;
    }
    
    .footer-links {
        grid-column: span 2;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
        width: 100%;
        flex-direction: column;
        gap: 10px;
        margin-top: 20px;
        padding: 20px 0;
        border-top: 1px solid var(--border-color);
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .nav-search {
        width: 100%;
        order: 3;
        max-width: 100%;
    }
    
    .nav-actions {
        display: none;
    }
    
    .nav-wrapper {
        flex-direction: column;
        align-items: stretch;
    }
    
    .hero-section {
        padding: 80px 0 60px;
    }
    
    .hero-title {
        font-size: 32px;
    }
    
    .hero-subtitle {
        font-size: 18px;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .comics-grid {
        grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
        gap: 15px;
    }
    
    .comic-image {
        height: 240px;
    }
    
    .categories-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
    }
    
    .contact-info {
        margin-top: 15px;
        padding-top: 15px;
    }
    
    .membership-text h2,
    .app-text h2 {
        font-size: 28px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero-title {
        font-size: 24px;
    }
    
    .hero-subtitle {
        font-size: 16px;
    }
    
    .section-title {
        font-size: 24px;
    }
    
    .hero-buttons,
    .membership-buttons {
        flex-direction: column;
        width: 100%;
    }
    
    .btn-primary,
    .btn-secondary {
        width: 100%;
        text-align: center;
    }
    
    .comics-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }
    
    .comic-image {
        height: 200px;
    }
    
    .categories-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .new-comic-card {
        min-width: 160px;
    }
    
    .new-comic-card .comic-image {
        height: 240px;
    }
    
    .ranking-grid {
        grid-template-columns: 1fr;
    }
    
    .back-to-top {
        width: 45px;
        height: 45px;
        bottom: 20px;
        right: 20px;
        font-size: 20px;
    }
}

/* 跳过链接（屏幕阅读器） */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary-color);
    color: white;
    padding: 8px 16px;
    text-decoration: none;
    z-index: 100;
    border-radius: 0 0 4px 0;
}

.skip-link:focus {
    top: 0;
}

/* 性能优化 - 图片懒加载 */
img[loading="lazy"] {
    opacity: 0;
    transition: opacity 0.3s;
}

img[loading="lazy"].loaded {
    opacity: 1;
}

/* 图片加载错误处理 */
img {
    object-fit: cover;
}

img[src=""],
img:not([src]) {
    opacity: 0;
}

/* 打印样式 */
@media print {
    .main-header,
    .footer,
    .mobile-menu-toggle,
    .nav-search,
    .back-to-top {
        display: none;
    }
    
    body {
        background: white;
        color: black;
    }
    
    a {
        color: black;
        text-decoration: underline;
    }
}