/**
 * 电子书店全局样式
 * 现代化 UI 美化
 */

/* ==================== 导入字体 ==================== */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;400;500;600;700&display=swap');

/* ==================== 设计令牌 ==================== */
:root {
    /* 主色调 - 优雅紫 */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --primary-ghost: rgba(99, 102, 241, 0.1);
    
    /* 辅助色 */
    --secondary: #64748b;
    --accent: #f59e0b;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --info: #3b82f6;
    
    /* 背景色 */
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f1f5f9;
    
    /* 文字色 */
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --text-inverse: #ffffff;
    
    /* 边框 */
    --border-light: #e2e8f0;
    --border-medium: #cbd5e1;
    
    /* 阴影 */
    --shadow-sm: 0 1px 2px 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);
    --shadow-glow: 0 0 30px rgba(99, 102, 241, 0.25);
    
    /* 圆角 */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;
    
    /* 过渡 */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 350ms ease;
}

/* ==================== 基础样式 ==================== */
* {
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ==================== 导航栏美化 ==================== */
.navbar {
    background: rgba(255, 255, 255, 0.95) !important;
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    padding: 0.75rem 0;
    transition: all var(--transition-normal);
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.35rem;
    color: var(--primary) !important;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.navbar-brand i {
    font-size: 1.5rem;
}

.navbar .nav-link {
    color: var(--text-secondary) !important;
    font-weight: 500;
    padding: 0.5rem 1rem !important;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
    text-decoration: none;
}

.navbar .nav-link:hover {
    color: var(--primary) !important;
    background: var(--primary-ghost);
    text-decoration: none;
}

.navbar .nav-link.active {
    color: var(--primary) !important;
    background: var(--primary-ghost);
    text-decoration: none;
}

/* ==================== Hero 区域 ==================== */
.hero-section {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 50%, #7c3aed 100%);
    position: relative;
    overflow: hidden;
    padding: 5rem 0;
    margin-bottom: 3rem;
}

.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='100' height='100' viewBox='0 0 100 100' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M11 18c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm48 25c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm-43-7c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm63 31c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM34 90c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm56-76c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM12 86c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm28-65c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm23-11c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-6 60c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm29 22c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zM32 63c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm57-13c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-9-21c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM60 91c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM35 41c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2z' fill='%23ffffff' fill-opacity='0.03' fill-rule='evenodd'/%3E%3C/svg%3E");
}

.hero-section h1 {
    font-weight: 700;
    font-size: 3rem;
    color: white;
    margin-bottom: 1rem;
}

.hero-section .lead {
    font-size: 1.25rem;
    color: rgba(255,255,255,0.9);
}

.hero-badge {
    background: rgba(255,255,255,0.2);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-full);
    font-weight: 500;
    display: inline-block;
    margin-bottom: 1rem;
}

/* ==================== 推荐书籍楼层 ==================== */
.featured-section {
    background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
    padding: 3rem 0;
    margin: 2rem 0;
    border-radius: var(--radius-xl);
}

.featured-badge {
    position: absolute;
    top: 10px;
    right: 10px;
    background: linear-gradient(135deg, #f59e0b, #d97706);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
    box-shadow: 0 2px 8px rgba(245, 158, 11, 0.4);
}

/* ==================== 分类标签 ==================== */
.category-filters {
    display: flex;
    flex-wrap: nowrap;
    justify-content: space-between;
    margin-bottom: 1.5rem;
    padding: 4px;
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    align-items: center;
}

.category-btn {
    padding: 2px 8px;
    border-radius: 0;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    text-decoration: none;
    display: inline-block;
    white-space: nowrap;
}

.category-btn:hover {
    color: var(--primary);
    background: var(--primary-ghost);
    text-decoration: none;
}

.category-btn.active {
    background: var(--primary);
    color: white;
    text-decoration: none;
}

/* ==================== 书籍卡片 ==================== */
.book-card {
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
    border: 1px solid var(--border-light);
    height: 100%;
    display: flex;
    flex-direction: column;
}

.book-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-light);
}

.book-card-img {
    position: relative;
    height: 200px;
    overflow: hidden;
    background: linear-gradient(135deg, #f1f5f9 0%, #e2e8f0 100%);
}

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

.book-card:hover .book-card-img img {
    transform: scale(1.05);
}

.book-card-img .category-tag {
    position: absolute;
    top: 0.75rem;
    left: 0.75rem;
    background: var(--primary);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-full);
    font-size: 0.7rem;
    font-weight: 600;
}

.book-card-img .price-tag {
    position: absolute;
    bottom: 0.75rem;
    right: 0.75rem;
    background: rgba(255,255,255,0.95);
    color: var(--primary);
    padding: 0.35rem 0.85rem;
    border-radius: var(--radius-full);
    font-weight: 700;
    font-size: 0.9rem;
    box-shadow: var(--shadow-md);
}

.book-card-body {
    padding: 1.25rem;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.book-card-title {
    font-weight: 600;
    font-size: 1.05rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    line-height: 1.4;
}

.book-card-desc {
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-bottom: 1rem;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    flex: 1;
}

.book-card-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 0.75rem;
    border-top: 1px solid var(--border-light);
    font-size: 0.8rem;
    color: var(--text-muted);
}

.book-card-meta i {
    margin-right: 0.25rem;
}

/* ==================== 按钮样式 ==================== */
.btn-primary-gradient {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    border: none;
    font-weight: 600;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
    box-shadow: 0 4px 14px rgba(99, 102, 241, 0.4);
}

.btn-primary-gradient:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.5);
    color: white;
}

.btn-buy {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    border: none;
    font-weight: 600;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
    box-shadow: 0 4px 14px rgba(99, 102, 241, 0.4);
}

.btn-buy:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.5);
    color: white;
}

.btn-read {
    background: linear-gradient(135deg, var(--success) 0%, #059669 100%);
    color: white;
    border: none;
    font-weight: 600;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
    box-shadow: 0 4px 14px rgba(16, 185, 129, 0.4);
}

.btn-read:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(16, 185, 129, 0.5);
    color: white;
}

.btn-preview {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
    font-weight: 600;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    transition: all var(--transition-normal);
}

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

/* ==================== 页面标题 ==================== */
.page-title {
    font-weight: 700;
    font-size: 2rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.page-subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* ==================== 搜索框 ==================== */
.search-box {
    position: relative;
    margin-bottom: 2rem;
}

.search-box input {
    width: 100%;
    padding: 1rem 1.25rem;
    padding-left: 3rem;
    border: 2px solid var(--border-light);
    border-radius: var(--radius-lg);
    font-size: 1rem;
    transition: all var(--transition-fast);
    background: var(--bg-secondary);
}

.search-box input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px var(--primary-ghost);
}

.search-box i {
    position: absolute;
    left: 1.25rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    font-size: 1.1rem;
}

/* ==================== 书籍详情页 ==================== */
.book-detail-header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    padding: 3rem 0;
    margin-bottom: 2rem;
    position: relative;
    overflow: hidden;
}

.book-detail-header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.book-cover-large {
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
    position: relative;
}

.book-cover-large img {
    width: 100%;
    display: block;
}

.book-info h1 {
    font-weight: 700;
    font-size: 2.25rem;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.book-meta-list {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.book-meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
}

.book-meta-item i {
    color: var(--primary);
}

.book-price-display {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 1.5rem;
}

.book-description {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 2rem;
}

/* ==================== 模态框美化 ==================== */
.modal-content {
    border: none;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
}

.modal-header {
    border-bottom: 1px solid var(--border-light);
    padding: 1.5rem;
}

.modal-header .modal-title {
    font-weight: 600;
    color: var(--text-primary);
}

.modal-body {
    padding: 1.5rem;
}

.modal-footer {
    border-top: 1px solid var(--border-light);
    padding: 1rem 1.5rem;
}

.btn-close:focus {
    box-shadow: 0 0 0 4px var(--primary-ghost);
}

/* ==================== Footer 美化 ==================== */
.footer {
    background: var(--text-primary);
    color: rgba(255,255,255,0.7);
    padding: 3rem 0 2rem;
    margin-top: 4rem;
}

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

.footer a:hover {
    color: white;
}

.footer-title {
    color: white;
    font-weight: 600;
    margin-bottom: 1rem;
}

/* ==================== 空状态 ==================== */
.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-secondary);
}

.empty-state i {
    font-size: 4rem;
    color: var(--border-medium);
    margin-bottom: 1rem;
}

.empty-state h4 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

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

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.animate-fade-in-up {
    animation: fadeInUp 0.5s ease-out forwards;
}

.animate-float {
    animation: float 3s ease-in-out infinite;
}

/* 延迟动画 */
.delay-100 { animation-delay: 0.1s; }
.delay-200 { animation-delay: 0.2s; }
.delay-300 { animation-delay: 0.3s; }
.delay-400 { animation-delay: 0.4s; }
.delay-500 { animation-delay: 0.5s; }

/* ==================== 滚动条美化 ==================== */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-tertiary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-medium);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--secondary);
}

/* ==================== 响应式 ==================== */
@media (max-width: 768px) {
    .hero-section {
        padding: 3rem 0;
    }
    
    .hero-section h1 {
        font-size: 2rem;
    }
    
    .book-card-img {
        height: 160px;
    }
    
    .category-filters {
        padding: 0.75rem;
    }
    
    .book-detail-header {
        padding: 2rem 0;
    }
    
    .book-info h1 {
        font-size: 1.75rem;
    }
}