/* 基础重置与宋代青绿山水主题变量 */
:root {
    --bg-silk: #F2EAD9;          /* Aged silk background */
    --text-ink: #2B2620;         /* Ink brown-black */
    --color-azurite: #2E6E8E;    /* Azurite blue (石青) */
    --color-malachite: #4E8570;  /* Malachite green (石绿) */
    --color-ochre: #B98A45;      /* Ochre gold (赭石) */
    
    --radius-lg: 24px;           /* Large soft radii */
    --shadow-soft: 0 8px 30px rgba(43, 38, 32, 0.08);
    --border-thin: 1px solid var(--color-ochre);
    
    --font-serif: 'Noto Serif SC', serif;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-serif);
    color: var(--text-ink);
    background-color: var(--bg-silk);
    /* 模拟绢本材质纹理效果 */
    background-image: url("data:image/svg+xml,%3Csvg width='100' height='100' viewBox='0 0 100 100' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100' height='100' filter='url(%23noise)' opacity='0.03'/%3E%3C/svg%3E");
    line-height: 2; /* Wide leading */
    letter-spacing: 0.5px;
}

a {
    text-decoration: none;
    color: var(--color-azurite);
    transition: color 0.3s;
}

a:hover {
    color: var(--color-malachite);
}

/* 布局工具 */
.container {
    width: 100%;
    max-width: 1100px; /* 较窄以增强古典感 */
    margin: 0 auto;
    padding: 0 20px;
}

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

/* 页眉与导航 */
.top-header {
    border-bottom: var(--border-thin);
    background-color: rgba(242, 234, 217, 0.9);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(5px);
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

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

.brand-name {
    font-size: 1.6rem;
    font-weight: 900;
    color: var(--color-azurite);
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 25px;
}

.nav-links a {
    color: var(--text-ink);
    font-weight: 600;
    font-size: 1.1rem;
}

.nav-links a:hover, .nav-highlight {
    color: var(--color-ochre);
}

.nav-highlight {
    border-bottom: 2px solid var(--color-ochre);
}

/* 章节通用样式 (长卷风格) */
.scroll-section {
    padding: 100px 0;
    border-bottom: var(--border-thin);
}

.scroll-section:last-child {
    border-bottom: none;
}

.has-bg {
    background-color: rgba(46, 110, 142, 0.03); /* 淡青色背景 */
}

.section-title {
    font-size: 2.2rem;
    margin-bottom: 60px;
    color: var(--color-azurite);
    font-weight: 900;
    position: relative;
    display: inline-block;
    left: 50%;
    transform: translateX(-50%);
}

.section-title::after {
    content: '';
    display: block;
    width: 40%;
    height: 2px;
    background-color: var(--color-ochre);
    margin: 15px auto 0;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 14px 32px;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: var(--radius-lg);
    transition: all 0.3s ease;
    cursor: pointer;
    text-align: center;
    border: 1px solid transparent;
}

.btn-primary {
    background-color: var(--color-azurite);
    color: var(--bg-silk);
}

.btn-primary:hover {
    background-color: var(--color-malachite);
    color: var(--bg-silk);
}

.btn-secondary {
    background-color: var(--color-malachite);
    color: var(--bg-silk);
}

.btn-secondary:hover {
    background-color: var(--color-azurite);
    color: var(--bg-silk);
}

.btn-outline {
    background-color: transparent;
    color: var(--text-ink);
    border: 1px solid var(--color-ochre);
}

.btn-outline:hover {
    background-color: var(--color-ochre);
    color: var(--bg-silk);
}

/* 网格系统 */
.grid-2, .grid-3 {
    display: grid;
    gap: 40px;
}
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }

/* 卡片样式 */
.card {
    background: rgba(255, 255, 255, 0.4);
    padding: 50px 35px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-soft);
    border: var(--border-thin);
    transition: transform 0.4s ease;
}

.card:hover {
    transform: translateY(-8px);
}

.card h3 {
    font-size: 1.4rem;
    margin-bottom: 20px;
    color: var(--color-malachite);
}

/* 主视觉区 (Hero) */
.hero {
    padding: 140px 0 120px;
}

.hero h1 {
    font-size: 3.2rem;
    margin-bottom: 25px;
    font-weight: 900;
    color: var(--text-ink);
    letter-spacing: 2px;
}

.hero .subtitle {
    font-size: 1.25rem;
    color: var(--text-ink);
    opacity: 0.8;
    margin-bottom: 50px;
    max-width: 750px;
    margin-left: auto;
    margin-right: auto;
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

/* 价格表 (Pricing) */
.pricing-card {
    text-align: center;
    position: relative;
}

.pricing-card.popular {
    border: 2px solid var(--color-azurite);
    background: rgba(255,255,255,0.7);
}

.badge {
    position: absolute;
    top: -16px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--color-ochre);
    color: var(--bg-silk);
    padding: 6px 20px;
    border-radius: var(--radius-lg);
    font-size: 0.9rem;
    font-weight: 600;
    letter-spacing: 1px;
}

.price {
    font-size: 2.8rem;
    font-weight: 900;
    color: var(--color-azurite);
    margin: 25px 0;
}

.price span {
    font-size: 1.2rem;
    color: var(--text-ink);
    opacity: 0.7;
}

.features-list {
    list-style: none;
    margin-bottom: 40px;
    text-align: center;
}

.features-list li {
    padding: 12px 0;
    border-bottom: 1px dashed var(--color-ochre);
    opacity: 0.9;
}
.features-list li:last-child {
    border-bottom: none;
}

/* FAQ */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    margin-bottom: 30px;
    background: rgba(255, 255, 255, 0.4);
    padding: 30px;
    border-radius: var(--radius-lg);
    border: var(--border-thin);
}

.faq-item h4 {
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: var(--color-azurite);
}

/* 页脚 (Footer) */
.footer {
    padding: 60px 0;
    border-top: var(--border-thin);
    background-color: rgba(46, 110, 142, 0.05);
}

.footer-links {
    margin-bottom: 25px;
}

.footer-links a {
    color: var(--color-malachite);
    margin: 0 20px;
    font-weight: 600;
}

.copyright {
    color: var(--text-ink);
    opacity: 0.6;
    font-size: 0.9rem;
}

/* 简单的子页面内容区域 */
.page-content {
    padding: 80px 0;
    max-width: 800px;
    margin: 0 auto;
    min-height: 60vh;
}
.page-content h1 {
    color: var(--color-azurite);
    margin-bottom: 40px;
    text-align: center;
}
.page-content h2 {
    color: var(--color-malachite);
    margin: 40px 0 20px;
}

/* 响应式设计 (媒体查询) */
@media (max-width: 992px) {
    .grid-3 { grid-template-columns: repeat(2, 1fr); }
    
    .nav-links {
        display: none; /* 移动端可以考虑隐藏或者做汉堡菜单，保持极简先简单隐藏部分链接 */
    }
}

@media (max-width: 768px) {
    .grid-2, .grid-3 { grid-template-columns: 1fr; }
    
    .hero { padding: 80px 0 60px; }
    .hero h1 { font-size: 2.2rem; }
    
    .hero-actions {
        flex-direction: column;
        width: 100%;
    }
    
    .btn {
        width: 100%;
        padding: 16px 20px;
    }
    
    .section-title { font-size: 1.8rem; }
    .scroll-section { padding: 60px 0; }
    
    .footer-links {
        display: flex;
        flex-direction: column;
        gap: 15px;
    }
    .footer-links a { margin: 0; }
}
/* SEO & Nav UI Updates */
.breadcrumb {
    font-size: 0.95rem;
    color: var(--text-ink);
    opacity: 0.8;
    margin-bottom: 30px;
    border-bottom: 1px dashed var(--color-ochre);
    padding-bottom: 10px;
}
.breadcrumb a { color: var(--color-azurite); }
.breadcrumb span { color: var(--color-malachite); font-weight: 600; }

.article-nav {
    display: flex;
    justify-content: space-between;
    margin-top: 60px;
    padding-top: 30px;
    border-top: var(--border-thin);
}

.floating-buttons {
    position: fixed;
    bottom: 40px;
    right: 40px;
    display: flex;
    flex-direction: column;
    gap: 15px;
    z-index: 1000;
}
.float-btn {
    width: 50px;
    height: 50px;
    background: rgba(242, 234, 217, 0.9);
    border: 2px solid var(--color-ochre);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    color: var(--color-azurite);
    box-shadow: var(--shadow-soft);
    backdrop-filter: blur(4px);
    transition: all 0.3s;
}
.float-btn:hover {
    background: var(--color-azurite);
    color: var(--bg-silk);
    transform: translateY(-5px);
}

.hero-image-wrapper {
    margin: 60px auto 0;
    max-width: 900px;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-soft);
    border: 3px solid var(--color-ochre);
    position: relative;
}
.hero-image-wrapper img {
    width: 100%;
    height: auto;
    display: block;
    opacity: 0.9;
}
.hero-image-wrapper::after {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: linear-gradient(to bottom, rgba(242, 234, 217, 0.05), rgba(242, 234, 217, 0.25));
    pointer-events: none;
}