/* 全局样式 */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Helvetica Neue', Arial, 'PingFang SC', 'Microsoft YaHei', sans-serif;
        }
        
        body {
            background-color: #f9f9f9;
            color: #333;
            line-height: 1.6;
        }
        
        a {
            text-decoration: none;
            color: inherit;
        }
        
        ul {
            list-style: none;
        }
        
        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }
        
        /* 头部样式 */
        header {
            background-color: #fff;
            box-shadow: 0 2px 15px rgba(0, 0, 0, 0.08);
            position: sticky;
            top: 0;
            z-index: 100;
        }
        
        .header-top {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 20px 0;
        }
        
        .logo {
            display: flex;
            align-items: center;
        }
        
        .logo img {
            height: 48px;
            margin-right: 12px;
        }
        
        .logo h1 {
            font-size: 28px;
            font-weight: 700;
            background: linear-gradient(135deg, #ff8a00, #ff4d00);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            letter-spacing: 1px;
        }
        
        .user-actions a {
            margin-left: 24px;
            font-size: 15px;
            color: #666;
            transition: color 0.3s;
            font-weight: 500;
        }
        
        .user-actions a:hover {
            color: #ff6b00;
        }
        
        .user-actions .login {
            padding: 10px 20px;
            border: 1px solid #ff6b00;
            border-radius: 6px;
            color: #ff6b00;
            transition: all 0.3s;
        }
        
        .user-actions .login:hover {
            background-color: #fff5f0;
        }
        
        .user-actions .register {
            padding: 10px 20px;
            background: linear-gradient(135deg, #ff8a00, #ff4d00);
            border-radius: 6px;
            color: white;
            transition: all 0.3s;
            box-shadow: 0 4px 12px rgba(255, 107, 0, 0.2);
        }
        
        .user-actions .register:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 16px rgba(255, 107, 0, 0.3);
        }
        
        nav {
            padding: 18px 0;
            border-top: 1px solid #f0f0f0;
        }
        
        nav ul {
            display: flex;
            justify-content: center;
        }
        
        nav ul li {
            margin: 0 25px;
        }
        
        nav ul li a {
            color: #555;
            font-weight: 500;
            padding: 8px 0;
            position: relative;
            font-size: 16px;
            letter-spacing: 0.5px;
        }
        
        nav ul li a:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 0;
            height: 3px;
            background: linear-gradient(90deg, #ff8a00, #ff4d00);
            transition: width 0.3s;
        }
        
        nav ul li a:hover:after {
            width: 100%;
        }
        
        nav ul li a.active {
            color: #ff6b00;
        }
        
        nav ul li a.active:after {
            width: 100%;
        }
        
        /* 搜索区域 */
        .hero-section {
            background: linear-gradient(135deg, #ff9a00, #ff6b00);
            padding: 80px 0 100px;
            text-align: center;
            color: white;
            position: relative;
            overflow: hidden;
        }
        
        .hero-section:before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" preserveAspectRatio="none"><path fill="rgba(255,255,255,0.05)" d="M0,0 L100,0 L100,100 L0,100 Z" /></svg>');
            background-size: cover;
            opacity: 0.1;
        }
        
        .hero-content {
            position: relative;
            z-index: 1;
            max-width: 800px;
            margin: 0 auto;
        }
        
        .hero-content h2 {
            font-size: 42px;
            margin-bottom: 20px;
            font-weight: 700;
            letter-spacing: 1px;
            text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
        }
        
        .hero-content p {
            font-size: 18px;
            margin-bottom: 40px;
            line-height: 1.8;
            opacity: 0.9;
            max-width: 700px;
            margin-left: auto;
            margin-right: auto;
        }
        
        .search-box {
            max-width: 800px;
            margin: 0 auto;
            position: relative;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
            border-radius: 50px;
            overflow: hidden;
        }
        
        .search-box input {
            width: 100%;
            padding: 18px 25px;
            border: none;
            border-radius: 50px;
            font-size: 16px;
            outline: none;
            transition: all 0.3s;
        }
        
        .search-box input:focus {
            box-shadow: 0 0 0 3px rgba(255, 107, 0, 0.3);
        }
        
        .search-box button {
            position: absolute;
            right: 5px;
            top: 5px;
            background: linear-gradient(135deg, #ff8a00, #ff4d00);
            color: white;
            border: none;
            border-radius: 50px;
            padding: 13px 30px;
            font-size: 16px;
            font-weight: 500;
            cursor: pointer;
            transition: all 0.3s;
            box-shadow: 0 4px 12px rgba(255, 107, 0, 0.3);
        }
        
        .search-box button:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 16px rgba(255, 107, 0, 0.4);
        }
        
        /* 电子书列表 */
        .book-section {
            padding: 60px 0;
            background-color: #fff;
        }
        
        .section-title {
            text-align: center;
            margin-bottom: 50px;
        }
        
        .section-title h3 {
            font-size: 32px;
            color: #333;
            margin-bottom: 15px;
            font-weight: 600;
            position: relative;
            display: inline-block;
        }
        
        .section-title h3:after {
            content: '';
            position: absolute;
            bottom: -10px;
            left: 50%;
            transform: translateX(-50%);
            width: 60px;
            height: 3px;
            background: linear-gradient(90deg, #ff8a00, #ff4d00);
        }
        
        .section-title p {
            color: #777;
            font-size: 16px;
            max-width: 600px;
            margin: 0 auto;
        }
        
        .book-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 30px;
            margin-bottom: 50px;
        }
        
        .book-card {
            background-color: white;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: 0 8px 20px rgba(0, 0, 0, 0.06);
            transition: all 0.3s ease-out;
            border: 1px solid #f0f0f0;
        }
        
        .book-card:hover {
            transform: translateY(-8px);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
        }
        
        .book-cover {
            /* height: 220px; */
            overflow: hidden;
            position: relative;

            width: 100%;
            display: flex;
            justify-content: center;


        }
        
        .book-cover:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 100%;
            height: 40%;
            background: linear-gradient(to top, rgba(0,0,0,0.1), transparent);
        }
        
        .book-cover img {
            width: 50%;
            height: 100%;
            object-fit: cover;
            transition: transform 0.5s;

            max-width: 100%; /* 图片宽度自适应容器 */
            height: auto; /* 保持宽高比例 */
        }
        
        .book-card:hover .book-cover img {
            transform: scale(1.05);
        }






        
        .book-info {
            padding: 20px;
        }
        
        .book-title {
            font-size: 17px;
            font-weight: 600;
            margin-bottom: 8px;
            line-height: 1.4;
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
            overflow: hidden;
            height: 48px;
        }
        
        .book-author {
            font-size: 14px;
            color: #666;
            margin-bottom: 8px;
        }
        
        .book-publisher {
            font-size: 13px;
            color: #888;
            margin-bottom: 8px;
        }
        
        .book-isbn {
            font-size: 12px;
            color: #999;
            font-family: monospace;
        }
        
        /* 分页 */
        .pagination {
            display: flex;
            justify-content: center;
            margin-top: 40px;
        }
        
        .pagination a {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 40px;
            height: 40px;
            margin: 0 5px;
            border-radius: 50%;
            color: #666;
            transition: all 0.3s;
            font-weight: 500;
        }
        
        .pagination a.active, .pagination a:hover {
            background: linear-gradient(135deg, #ff8a00, #ff4d00);
            color: white;
            box-shadow: 0 4px 12px rgba(255, 107, 0, 0.3);
        }
        
        .pagination a.disabled {
            color: #ccc;
            pointer-events: none;
        }
        
        /* 特色区域 */
        .features {
            padding: 80px 0;
            background-color: #fafafa;
        }
        
        .feature-container {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 40px;
        }
        
        .feature-item {
            text-align: center;
            padding: 40px 30px;
            background-color: white;
            border-radius: 12px;
            box-shadow: 0 8px 20px rgba(0, 0, 0, 0.04);
            transition: all 0.3s ease-out;
        }
        
        .feature-item:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.08);
        }
        
        .feature-icon {
            width: 70px;
            height: 70px;
            margin: 0 auto 25px;
            background: linear-gradient(135deg, #ff8a00, #ff4d00);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 32px;
            box-shadow: 0 8px 20px rgba(255, 107, 0, 0.2);
        }
        
        .feature-item h4 {
            font-size: 20px;
            margin-bottom: 15px;
            color: #333;
            font-weight: 600;
        }
        
        .feature-item p {
            color: #777;
            font-size: 15px;
            line-height: 1.7;
        }
        
        /* 页脚 */
        footer {
            background-color: #222;
            color: #aaa;
            padding: 70px 0 30px;
        }
        
        .footer-content {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 40px;
            margin-bottom: 50px;
        }
        
        .footer-column h4 {
            color: white;
            font-size: 18px;
            margin-bottom: 25px;
            position: relative;
            padding-bottom: 12px;
            font-weight: 600;
        }
        
        .footer-column h4:after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 40px;
            height: 3px;
            background: linear-gradient(90deg, #ff8a00, #ff4d00);
        }
        
        .footer-column ul li {
            margin-bottom: 12px;
        }
        
        .footer-column ul li a {
            transition: color 0.3s;
            font-size: 14px;
        }
        
        .footer-column ul li a:hover {
            color: #ff6b00;
        }
        
        .footer-bottom {
            text-align: center;
            padding-top: 30px;
            border-top: 1px solid #444;
            font-size: 14px;
            color: #777;
        }
        
        /* 响应式设计 */
        @media (max-width: 1200px) {
            .book-grid {
                grid-template-columns: repeat(3, 1fr);
            }
            
            .feature-container {
                gap: 30px;
            }
        }
        
        @media (max-width: 992px) {
            .hero-content h2 {
                font-size: 36px;
            }
            
            .book-grid {
                grid-template-columns: repeat(2, 1fr);
                gap: 25px;
            }
            
            .feature-container {
                grid-template-columns: repeat(2, 1fr);
            }
            
            .footer-content {
                grid-template-columns: repeat(2, 1fr);
                gap: 30px;
            }
        }
        
        @media (max-width: 768px) {
            .header-top {
                flex-direction: column;
                text-align: center;
            }
            
            .user-actions {
                margin-top: 20px;
            }
            
            nav ul {
                flex-wrap: wrap;
                justify-content: center;
            }
            
            nav ul li {
                margin: 0 15px 10px;
            }
            
            .hero-content h2 {
                font-size: 32px;
            }
            
            .hero-content p {
                font-size: 16px;
            }
            
            .feature-container {
                grid-template-columns: 1fr;
                gap: 25px;
            }
        }
        
        @media (max-width: 576px) {
            .hero-section {
                padding: 60px 0 80px;
            }
            
            .hero-content h2 {
                font-size: 28px;
            }
            
            .search-box input {
                padding: 15px 20px;
            }
            
            .search-box button {
                padding: 10px 20px;
            }
            
            .book-grid {
                grid-template-columns: 1fr;
            }
            
            .footer-content {
                grid-template-columns: 1fr;
            }
        }



        .loading-container {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
}

.dot {
    display: inline-block;
    width: 8px;
    height: 8px;
    background-color: #ff6b00;
    border-radius: 50%;
    animation: bounce 1.4s infinite ease-in-out both;
}

.dot:nth-child(1) {
    animation-delay: -0.32s;
}

.dot:nth-child(2) {
    animation-delay: -0.16s;
}

@keyframes bounce {
    0%, 80%, 100% {
        transform: scale(0);
    } 40% {
        transform: scale(1.0);
    }
}