/* =========================================
   Readori UI 核心样式表 - 完整版
   风格: 人文极简风 (Minimalist & Literary)
========================================= */

:root {
    /* 核心色彩体系 - 宣纸与水墨 */
    --bg-primary: #f9f8f6; /* 宣纸白 */
    --bg-secondary: #ffffff;
    --text-primary: #2c2c2c; /* 徽墨黑 */
    --text-secondary: #666666;
    
    /* 品牌点缀色 - 竹青 */
    --brand-color: #2d4a3e;
    --brand-hover: #1e332a;
    --brand-light: #e5ede9;

    /* 边框与阴影 */
    --border-color: rgba(0, 0, 0, 0.08);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 12px 32px rgba(0, 0, 0, 0.06), 0 4px 12px rgba(0, 0, 0, 0.04);
    
    /* 字体栈 (中英混合优化) */
    --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", "PingFang SC", "Microsoft YaHei", sans-serif;
    --font-serif: "Songti SC", "STSong", "Source Han Serif SC", "Noto Serif CJK SC", serif;
}

/* =========================================
   深色模式适配
========================================= */
.dark-mode {
    --bg-primary: #121212;
    --bg-secondary: #1e1e1e;
    --text-primary: #e0e0e0;
    --text-secondary: #999999;
    --brand-color: #4a7a66;
    --border-color: rgba(255, 255, 255, 0.08);
    --shadow-md: 0 12px 32px rgba(0, 0, 0, 0.4);
}

/* 系统偏好深色模式自动适配 */
@media (prefers-color-scheme: dark) {
    :root:not(.dark-mode) {
        --bg-primary: #121212;
        --bg-secondary: #1e1e1e;
        --text-primary: #e0e0e0;
        --text-secondary: #999999;
        --brand-color: #4a7a66;
        --border-color: rgba(255, 255, 255, 0.08);
        --shadow-md: 0 12px 32px rgba(0, 0, 0, 0.4);
    }
}

/* =========================================
   基础布局重置
========================================= */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-sans);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    /* 确保页脚置底的 Flex 布局 */
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

main {
    flex: 1; /* 撑开内容区，将 footer 推到底部 */
}

a { 
    text-decoration: none; 
    color: inherit; 
    transition: color 0.2s ease;
}

.container { 
    max-width: 1200px; 
    margin: 0 auto; 
    padding: 0 24px; 
}

/* =========================================
   导航栏 Navbar
========================================= */
.navbar {
    position: sticky;
    top: 0;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    background-color: rgba(249, 248, 246, 0.95);
    border-bottom: 1px solid var(--border-color);
    z-index: 100;
}

.dark-mode .navbar {
    background-color: rgba(18, 18, 18, 0.95);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 16px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 0.05em;
}

.logo span {
    font-family: var(--font-sans);
    font-weight: 500;
    color: var(--text-secondary);
    font-size: 1.2rem;
    margin-left: 8px;
}

.nav-links a {
    margin-left: 32px;
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.nav-links a:hover { color: var(--brand-color); }

.lang-toggle {
    margin-left: auto;
    margin-right: 16px;
    font-size: 0.9rem;
    color: var(--text-secondary);
    cursor: pointer;
}

.lang-toggle:hover { color: var(--brand-color); }

.theme-toggle {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 8px;
    display: flex;
    align-items: center;
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 8px;
    align-items: center;
}

/* =========================================
   首页 Hero Section
========================================= */
.hero {
    padding: 100px 24px;
    overflow: hidden;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
}

.badge {
    display: inline-block;
    padding: 6px 12px;
    border-radius: 20px;
    background: var(--brand-light);
    color: var(--brand-color);
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 24px;
}

.dark-mode .badge { background: rgba(74, 122, 102, 0.2); }

.hero-title {
    font-family: var(--font-serif);
    font-size: 3.5rem;
    line-height: 1.3;
    font-weight: 700;
    margin-bottom: 24px;
}

.hero-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 40px;
    max-width: 480px;
}

.hero-actions { display: flex; gap: 16px; }

.btn {
    padding: 14px 28px;
    border-radius: 8px;
    font-weight: 500;
    transition: all 0.2s;
}

.btn-primary {
    background-color: var(--brand-color);
    color: #fff;
    box-shadow: 0 4px 12px rgba(45, 74, 62, 0.2);
}

.btn-primary:hover {
    background-color: var(--brand-hover);
    transform: translateY(-2px);
}

.btn-secondary {
    border: 1px solid var(--border-color);
    background: transparent;
}

/* =========================================
   3D 书本 Mockup 组件
========================================= */
.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.css-book-mockup {
    display: flex;
    perspective: 1500px;
    background: #fff;
    padding: 30px;
    border-radius: 4px 12px 12px 4px;
    box-shadow: 
        10px 10px 40px rgba(0,0,0,0.1),
        1px 0px 0px #e0e0e0,
        2px 0px 0px #d0d0d0;
    transform: rotateY(-12deg) rotateX(4deg);
    position: relative;
    width: 100%;
    max-width: 480px;
    min-height: 300px;
    animation: float 6s ease-in-out infinite;
}

.dark-mode .css-book-mockup {
    background: var(--bg-secondary);
    box-shadow: 10px 10px 40px rgba(0,0,0,0.4);
}

/* 书脊阴影 */
.css-book-mockup::after {
    content: '';
    position: absolute;
    left: 50%; top: 0; bottom: 0; width: 20px;
    transform: translateX(-50%);
    background: linear-gradient(to right, rgba(0,0,0,0) 0%, rgba(0,0,0,0.05) 50%, rgba(0,0,0,0) 100%);
}

.book-page { flex: 1; display: flex; flex-direction: column; gap: 12px; padding: 10px; }
.skeleton-line { height: 8px; background: var(--border-color); border-radius: 2px; }
.skeleton-title { height: 18px; width: 70%; background: var(--brand-color); opacity: 0.2; margin-bottom: 12px; }
.skeleton-line.full { width: 100%; }
.skeleton-line.medium { width: 80%; }
.skeleton-line.short { width: 40%; }
.mt-1 { margin-top: 40px; }

@keyframes float {
    0%, 100% { transform: rotateY(-12deg) rotateX(4deg) translateY(0); }
    50% { transform: rotateY(-10deg) rotateX(2deg) translateY(-15px); }
}

/* =========================================
   Bento Grid 特性区域
========================================= */
.features-section {
    padding: 100px 0;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
}

.section-title {
    font-family: var(--font-serif);
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 64px;
}

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

.bento-card {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 40px;
    transition: transform 0.3s ease;
}

.bento-card:hover { transform: translateY(-5px); }
.card-large { grid-column: span 2; }
.card-icon { font-size: 2.5rem; margin-bottom: 24px; }
.bento-card h3 { font-family: var(--font-serif); font-size: 1.5rem; margin-bottom: 16px; }
.bento-card p { color: var(--text-secondary); line-height: 1.8; }

/* =========================================
   文档内页通用样式 (Privacy/Support/Rules)
========================================= */
.shell {
    max-width: 800px;
    margin: 0 auto;
    padding: 80px 24px;
}

.doc h1 {
    font-family: var(--font-serif);
    font-size: 2.8rem;
    margin-bottom: 32px;
}

.doc h2 {
    font-family: var(--font-serif);
    font-size: 1.8rem;
    margin: 48px 0 24px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 8px;
}

.doc p { margin-bottom: 20px; color: var(--text-secondary); font-size: 1.05rem; }
.doc ul { margin: 0 0 24px 24px; color: var(--text-secondary); }
.doc li { margin-bottom: 10px; }
.eyebrow { color: var(--brand-color); font-weight: 600; text-transform: uppercase; letter-spacing: 0.1em; font-size: 0.8rem; }
.update-notice { font-size: 0.9rem; opacity: 0.6; margin-bottom: 40px; }

/* =========================================
   页脚 Footer
========================================= */
.site-footer {
    padding: 80px 0 40px;
    background-color: var(--bg-primary);
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 60px;
    margin-bottom: 60px;
}

.footer-brand .logo { margin-bottom: 16px; }
.footer-brand p { color: var(--text-secondary); font-size: 0.95rem; }

.link-group h4 {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 24px;
    color: var(--text-primary);
}

.link-group a {
    display: block;
    color: var(--text-secondary);
    margin-bottom: 12px;
    font-size: 0.95rem;
}

.link-group a:hover { color: var(--brand-color); }

.footer-bottom {
    padding-top: 40px;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.85rem;
}

/* =========================================
   响应式设计 (Mobile & Tablet)
========================================= */
@media (max-width: 900px) {
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 48px;
    }

    .hero-subtitle { margin: 0 auto 40px; }
    .hero-actions { justify-content: center; }

    .css-book-mockup {
        transform: rotateY(0) rotateX(0); /* 移动端取消复杂旋转，防止切边 */
        margin: 0 auto;
        animation: none;
        box-shadow: var(--shadow-md);
    }

    .bento-grid { grid-template-columns: 1fr; }
    .card-large { grid-column: span 1; }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 40px;
    }
}

@media (max-width: 600px) {
    .hero-title { font-size: 2.5rem; }
    .nav-container {
        position: relative;
        flex-wrap: wrap;
        row-gap: 10px;
    }
    .nav-links {
        display: none;
        width: 100%;
        order: 10;
        margin-top: 8px;
        padding: 12px;
        background: var(--bg-secondary);
        border: 1px solid var(--border-color);
        border-radius: 10px;
        box-shadow: var(--shadow-sm);
    }
    .nav-links.is-open { display: flex; flex-direction: column; }
    .nav-links a { margin: 0; padding: 8px 0; }
    .mobile-menu-toggle { display: flex; }
    .lang-toggle { margin-left: 0; margin-right: 8px; }
    .hero-actions { flex-direction: column; }
    .hero { padding: 60px 20px; }
    .shell { padding: 40px 20px; }
    .doc h1 { font-size: 2.2rem; }
}