/* ====== CSS重置和基础样式 ====== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --text-primary: #2d3748;
    --text-secondary: #4a5568;
    --text-light: #718096;
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-secondary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ====== 重置所有列表样式 ====== */
ul, ol {
    list-style: none;
}

/* ====== 重置所有链接下划线 ====== */
a {
    text-decoration: none;
    color: inherit;
}

/* ====== 响应式容器 ====== */
.container {
    width: 100%;
    padding-right: var(--spacing-sm);
    padding-left: var(--spacing-sm);
    margin-right: auto;
    margin-left: auto;
}

@media (min-width: 640px) {
    .container {
        max-width: 640px;
    }
}

@media (min-width: 768px) {
    .container {
        max-width: 768px;
    }
}

@media (min-width: 1024px) {
    .container {
        max-width: 1024px;
    }
}

@media (min-width: 1280px) {
    .container {
        max-width: 1280px;
    }
}

/* ====== 页头样式 ====== */
.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    border-bottom: none;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--spacing-sm);
    padding-bottom: var(--spacing-sm);
    height: 64px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
}

.logo a {
    color: white;
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

/* 移动端菜单按钮 - 已修改让按钮靠右 */
.menu-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: background-color 0.2s;
    margin-left: auto; /* 将按钮推到最右边 */
    margin-right: 0.5rem; /* 保留一点右边距 */
}

.menu-toggle:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

/* ====== 导航菜单 - 移动端样式 ====== */
.nav-menu {
    display: none; /* 移动端默认隐藏 */
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: var(--shadow-lg);
    padding: var(--spacing-sm);
}

/* 移动端激活状态 */
.nav-menu.active {
    display: flex;
    flex-direction: column;
}

.nav-menu li {
    width: 100%;
}

.nav-menu a {
    display: block;
    padding: var(--spacing-sm);
    color: white;
    font-weight: 500;
    border-radius: var(--radius-sm);
    transition: background-color 0.2s, color 0.2s;
}

.nav-menu a:hover,
.nav-menu a.active {
    background-color: rgba(255, 255, 255, 0.1);
    color: white;
}

/* ====== 桌面端导航 ====== */
@media (min-width: 768px) {
    .menu-toggle {
        display: none;
        margin-left: 0; /* 重置margin */
        margin-right: 0; /* 重置margin */
    }
    
    /* 关键修复：桌面端总是显示横向菜单 */
    .nav-menu {
        display: flex; /* 覆盖移动端的display: none */
        position: static;
        flex-direction: row;
        gap: var(--spacing-md);
        border: none;
        box-shadow: none;
        padding: 0;
        background: transparent;
    }
    
    /* 确保active状态在桌面端也是横向 */
    .nav-menu.active {
        display: flex;
        flex-direction: row; /* 重要：保持横向 */
    }
    
    .nav-menu li {
        width: auto;
    }
    
    .nav-menu a {
        padding: var(--spacing-xs) var(--spacing-sm);
        position: relative;
    }
    
    .nav-menu a::after {
        content: '';
        position: absolute;
        bottom: 0;
        left: 0;
        width: 0;
        height: 2px;
        background: white;
        transition: width 0.3s ease;
    }
    
    .nav-menu a:hover::after,
    .nav-menu a.active::after {
        width: 100%;
    }
}

/* ====== 主要内容区域 ====== */
.main-content {
    flex: 1;
    padding: var(--spacing-lg) 0;
}

/* ====== 英雄区域 ====== */
.hero {
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-md);
    margin-bottom: var(--spacing-xl);
    background-color: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.hero h1 {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
    line-height: 1.3;
}

@media (min-width: 768px) {
    .hero h1 {
        font-size: 2.5rem;
    }
}

.hero p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto var(--spacing-lg);
    line-height: 1.6;
}

/* 统计数据 */
.hero-stats {
    display: flex;
    justify-content: center;
    gap: var(--spacing-xl);
    flex-wrap: wrap;
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: var(--spacing-xs);
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-light);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* ====== 搜索区域 ====== */
.search-section {
    margin-bottom: var(--spacing-xl);
}

.search-box {
    background-color: var(--bg-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.search-form {
    display: flex;
    margin-bottom: var(--spacing-md);
}

.search-input {
    flex: 1;
    padding: 0.75rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md) 0 0 var(--radius-md);
    font-size: 1rem;
    outline: none;
    transition: border-color 0.2s;
}

.search-input:focus {
    border-color: var(--primary-color);
}

.search-btn {
    padding: 0.75rem 1.5rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 0 var(--radius-md) var(--radius-md) 0;
    font-weight: 600;
    cursor: pointer;
    transition: opacity 0.2s;
}

.search-btn:hover {
    opacity: 0.9;
}

.search-tips {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.5rem;
    font-size: 0.9rem;
    color: var(--text-light);
}

.search-tips a {
    color: var(--primary-color);
}

.search-tips a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

/* 移动端搜索优化 */
@media (max-width: 640px) {
    .search-form {
        flex-direction: column;
    }
    
    .search-input {
        border-radius: var(--radius-md);
        margin-bottom: var(--spacing-sm);
    }
    
    .search-btn {
        border-radius: var(--radius-md);
        width: 100%;
    }
    
    .search-tips {
        justify-content: center;
    }
}

/* ====== 内容区块 ====== */
.content-section {
    margin-bottom: var(--spacing-xl);
}

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

.section-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--primary-color);
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 60px;
    height: 2px;
    background: var(--secondary-color);
}

.view-all {
    color: var(--primary-color);
    font-weight: 500;
    font-size: 0.9rem;
}

.view-all:hover {
    text-decoration: underline;
}

/* ====== 内容网格 ====== */
.content-grid {
    display: grid;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

@media (min-width: 640px) {
    .content-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 768px) {
    .content-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (min-width: 1024px) {
    .content-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

.content-card {
    background-color: var(--bg-primary);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s, box-shadow 0.2s;
    border: 1px solid var(--border-color);
}

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

.content-image {
    height: 180px;
    background-color: var(--bg-secondary);
    position: relative;
    overflow: hidden;
}

.content-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

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

.category-badge {
    position: absolute;
    top: var(--spacing-sm);
    left: var(--spacing-sm);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 500;
}

.content-info {
    padding: var(--spacing-md);
}

.content-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    line-height: 1.4;
}

.content-title a {
    color: var(--text-primary);
    display: block;
}

.content-title a:hover {
    color: var(--primary-color);
}

.content-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.85rem;
    color: var(--text-light);
    margin-bottom: var(--spacing-sm);
}

.content-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: var(--spacing-sm);
    border-top: 1px solid var(--border-color);
    font-size: 0.8rem;
    color: var(--text-light);
}

/* ====== 分类网格 ====== */
.category-grid {
    display: grid;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

@media (min-width: 640px) {
    .category-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 768px) {
    .category-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (min-width: 1024px) {
    .category-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

.category-card {
    background-color: var(--bg-primary);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
    text-align: center;
}

.category-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-color: transparent;
}

.category-card:hover .category-count {
    opacity: 0.9;
}

.category-icon {
    font-size: 2rem;
    margin-bottom: var(--spacing-sm);
}

.category-name {
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.category-count {
    font-size: 0.85rem;
    color: var(--text-light);
}

.category-card:hover .category-count {
    color: rgba(255, 255, 255, 0.9);
}

/* ====== 热门曲谱列表 ====== */
.hot-content-list {
    background-color: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.hot-content-item {
    display: flex;
    align-items: center;
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--border-color);
}

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

.hot-rank {
    width: 32px;
    height: 32px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    margin-right: var(--spacing-md);
    flex-shrink: 0;
}

.hot-content-link {
    flex: 1;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.hot-content-title {
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.hot-content-title a {
    color: var(--text-primary);
}

.hot-content-title a:hover {
    color: var(--primary-color);
}

.hot-content-meta {
    display: flex;
    gap: var(--spacing-md);
    font-size: 0.85rem;
    color: var(--text-light);
}

.hot-content-stats {
    display: flex;
    gap: var(--spacing-md);
    font-size: 0.85rem;
    color: var(--text-light);
}

/* 移动端热门列表优化 */
@media (max-width: 640px) {
    .hot-content-link {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
    }
    
    .hot-content-stats {
        align-self: flex-start;
    }
}

/* ====== 页脚 ====== */
.footer {
    background-color: var(--text-primary);
    color: white;
    padding: var(--spacing-xl) 0 var(--spacing-lg);
    margin-top: auto;
}

.footer-main {
    display: grid;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

@media (min-width: 768px) {
    .footer-main {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .footer-main {
        grid-template-columns: repeat(4, 1fr);
    }
}

.footer-column {
    margin-bottom: var(--spacing-lg);
}

.footer-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: white;
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.footer-links a {
    color: #cbd5e0;
    font-size: 0.9rem;
    transition: color 0.2s;
}

.footer-links a:hover {
    color: white;
    text-decoration: underline;
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid #4a5568;
    font-size: 0.85rem;
    color: #a0aec0;
}

.footer-bottom a {
    color: #a0aec0;
}

.footer-bottom a:hover {
    color: white;
    text-decoration: underline;
}

.sep {
    margin: 0 var(--spacing-sm);
    opacity: 0.5;
}

/* ====== 回到顶部按钮 ====== */
.back-to-top {
    position: fixed;
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    z-index: 99;
    box-shadow: var(--shadow-lg);
    transition: opacity 0.2s, transform 0.2s;
}

.back-to-top:hover {
    opacity: 0.9;
    transform: translateY(-2px);
}

/* ====== 工具类 ====== */
.text-center {
    text-align: center;
}

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

/* ====== 暗色模式 ====== */
@media (prefers-color-scheme: dark) {
    :root {
        --primary-color: #7c9bf5;
        --secondary-color: #9d7cf5;
        --text-primary: #f7fafc;
        --text-secondary: #e2e8f0;
        --text-light: #a0aec0;
        --bg-primary: #2d3748;
        --bg-secondary: #1a202c;
        --border-color: #4a5568;
        --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
        --shadow-md: 0 4px 6px rgba(0,0,0,0.3);
        --shadow-lg: 0 10px 15px rgba(0,0,0,0.3);
    }
    
    .header {
        background: linear-gradient(135deg, #5a6fd8 0%, #6a3f9a 100%);
    }
    
    .footer {
        background-color: #1a202c;
    }
    
    .search-input {
        background-color: #2d3748;
        border-color: #4a5568;
        color: #e2e8f0;
    }
}

/* ====== 打印样式 ====== */
@media print {
    .header, .footer, .search-section, .back-to-top {
        display: none !important;
    }
    
    body {
        background: white;
        color: black;
        font-size: 12pt;
    }
    
    .container {
        max-width: 100%;
        padding: 0;
    }
    
    .content-card {
        break-inside: avoid;
        box-shadow: none;
        border: 1px solid #ddd;
    }
}