/* ==========================================================================
   TxtPress Theme: Classic Binding (图书出版公司专属主题)
   纯 CSS 视觉实现，模拟纸张、书脊与烫金质感
   ========================================================================== */

/* --- 1. 全局变量与基础样式 --- */
:root {
    /* 核心色彩：墨蓝、装帧红、纸张白、烫金 */
    --primary-color: #1E2B3C; /* 深邃墨蓝 (经典硬壳书封) */
    --secondary-color: #8B2626; /* 经典装帧红 (书脊与高亮) */
    --accent-color: #C5A059; /* 哑光烫金色 */
    
    /* 纸张与墨水灰度 */
    --text-main: #2C2C2C; /* 碳素墨水黑 */
    --text-muted: #6B655D; /* 褪色铅灰 */
    --bg-body: #FDFBF7; /* 羊皮纸暖白 */
    --bg-surface: #FFFFFF; /* 纯白内页 */
    --border-light: #EBE5D9; /* 纸张边缘色 */
    --border-dark: #D4CDBB; /* 装订线色 */
    
    /* 视觉属性 (偏硬朗的书本质感) */
    --radius-sm: 2px;
    --radius-md: 4px;
    --radius-lg: 6px;
    --shadow-sm: 0 2px 4px rgba(30, 43, 60, 0.04);
    --shadow-md: 4px 4px 0px 0px rgba(235, 229, 217, 0.8), 0 4px 10px rgba(0,0,0,0.05); /* 叠纸感阴影 */
    --shadow-lg: 8px 8px 0px 0px rgba(235, 229, 217, 0.8), 0 10px 25px rgba(30, 43, 60, 0.08);
    --transition: all 0.4s cubic-bezier(0.25, 0.8, 0.25, 1);
    
    /* 字体排印：强调衬线体以体现文学性 */
    --font-heading: "Noto Serif SC", "Songti SC", "STSong", "Times New Roman", serif;
    --font-body: "Inter", -apple-system, "Microsoft YaHei", sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }

body {
    font-family: var(--font-body);
    line-height: 1.8;
    color: var(--text-main);
    background-color: var(--bg-body);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    /* 极其微弱的纸张纹理感背景色 */
    background-image: linear-gradient(to bottom, #FDFBF7, #F8F5EE);
}

/* 全局链接防跳色处理 */
a { color: var(--primary-color); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--secondary-color); }

main { flex: 1; }
.container { max-width: 1140px; margin: 0 auto; padding: 0 24px; width: 100%; }

/* 所有标题使用衬线体 */
h1, h2, h3, h4, h5, h6 { 
    font-family: var(--font-heading);
    color: var(--primary-color); 
    font-weight: 700; 
    line-height: 1.4; 
}

h2 { 
    font-size: 2.4rem; 
    text-align: center; 
    margin-bottom: 4rem; 
    position: relative; 
    letter-spacing: 2px;
}
/* 标题底部的经典图书双划线 */
h2::after { 
    content: ''; 
    position: absolute; 
    bottom: -20px; 
    left: 50%; 
    transform: translateX(-50%); 
    width: 60px; 
    height: 1px; 
    background-color: var(--secondary-color); 
    box-shadow: 0 4px 0 0 var(--secondary-color); /* 双线效果 */
}

section { padding: 100px 0; }
section:nth-of-type(even) { background-color: var(--bg-surface); border-top: 1px solid var(--border-light); border-bottom: 1px solid var(--border-light); }

/* 全局按钮：书签/藏书票风格 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 36px;
    background-color: var(--bg-body);
    color: var(--primary-color);
    text-decoration: none;
    border-radius: var(--radius-sm);
    font-family: var(--font-heading);
    font-weight: 600;
    font-size: 1.1rem;
    transition: var(--transition);
    border: 2px solid var(--primary-color);
    cursor: pointer;
    position: relative;
    overflow: hidden;
    z-index: 1;
}
.btn::before {
    content: '';
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background-color: var(--primary-color);
    transform: scaleX(0);
    transform-origin: right;
    transition: transform 0.4s ease;
    z-index: -1;
}
.btn:hover { color: var(--bg-surface); }
.btn:hover::before { transform: scaleX(1); transform-origin: left; }

/* --- 2. 头部导航 (经典出版设) --- */
.main-header { 
    background-color: var(--bg-surface); 
    border-bottom: 3px double var(--border-dark); /* 双线装订感 */
    position: sticky; 
    top: 0; 
    z-index: 1000; 
    width: 100%; 
    transition: var(--transition);
    box-shadow: 0 2px 10px rgba(0,0,0,0.02);
}
.main-header .container { 
    display: flex; 
    justify-content: space-between; 
    align-items: center; 
    height: 85px; 
}
.logo { 
    font-family: var(--font-heading);
    font-size: 1.5rem; /* 修复：考虑到公司名称较长，稍作字号缩减 */
    font-weight: 900; 
    color: var(--primary-color); 
    text-decoration: none; 
    letter-spacing: 1px;
    position: relative;
    white-space: nowrap; /* 修复：强制 Logo 不换行 */
    flex-shrink: 0; /* 修复：防止被导航栏挤压 */
}
.logo::before {
    content: '❖'; /* 经典藏书印记号 */
    color: var(--secondary-color);
    margin-right: 8px;
    font-size: 1.3rem;
}

.main-nav ul { display: flex; list-style: none; }
.main-nav ul li { margin-left: 25px; /* 修复：缩小菜单项间距，为长公司名腾出空间 */ }
.main-nav ul li a { 
    font-family: var(--font-heading);
    text-decoration: none; 
    color: var(--text-main); 
    font-weight: 600; 
    font-size: 1.05rem;
    transition: var(--transition);
    position: relative;
    padding-bottom: 5px;
    white-space: nowrap; /* 修复：强制菜单文字不折行、不竖排 */
}
/* 导航下划线：翻页效果 */
.main-nav ul li a::after {
    content: ''; position: absolute; bottom: 0; left: 0; width: 100%; height: 2px;
    background-color: var(--secondary-color);
    transform: scaleX(0); transform-origin: right; transition: transform 0.3s ease;
}
.main-nav ul li a:hover::after, .main-nav ul li a.active::after { 
    transform: scaleX(1); transform-origin: left; 
}
.main-nav ul li a:hover, .main-nav ul li a.active { color: var(--secondary-color); }
.menu-toggle { display: none; cursor: pointer; background: none; border: none; font-size: 2rem; color: var(--primary-color); }

/* --- 3. 首页 Hero 区域 (高级精装书封设计) --- */
#hero {
    background-color: var(--primary-color);
    background-image: linear-gradient(135deg, #16202D 0%, #1E2B3C 100%);
    position: relative;
    color: var(--bg-surface); 
    height: 80vh; 
    min-height: 550px;
    display: flex; 
    align-items: center; 
    justify-content: center; 
    text-align: center; 
    padding: 0 20px;
    overflow: hidden;
}
/* 纯CSS绘制的烫金书框线 */
#hero::after {
    content: '';
    position: absolute;
    top: 30px; left: 30px; right: 30px; bottom: 30px;
    border: 1px solid rgba(197, 160, 89, 0.4);
    outline: 1px solid rgba(197, 160, 89, 0.4);
    outline-offset: -8px;
    pointer-events: none;
    z-index: 1;
}
.hero-content {
    position: relative;
    z-index: 2;
    max-width: 750px;
    padding: 60px;
    background: rgba(30, 43, 60, 0.6);
    border-radius: 2px;
    backdrop-filter: blur(5px);
    animation: fadeRise 1s ease-out;
}
@keyframes fadeRise {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}
#hero h1 { 
    font-family: var(--font-heading);
    font-size: 3.5rem; 
    color: var(--bg-surface); 
    margin-bottom: 1.5rem; 
    letter-spacing: 2px;
    font-weight: 700;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}
#hero p { 
    font-size: 1.2rem; 
    color: #D4CDBB;
    margin: 0 auto 3rem; 
    font-weight: 400;
    line-height: 1.9;
    font-family: var(--font-heading);
}
#hero .btn {
    background-color: var(--accent-color);
    color: var(--primary-color);
    border-color: var(--accent-color);
}
#hero .btn::before { background-color: var(--bg-surface); }
#hero .btn:hover { color: var(--primary-color); }

/* --- 4. 解决方案 (精装书排列布局) --- */
#solutions { background-color: var(--bg-body); }
.solutions-grid { 
    display: grid; 
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); 
    gap: 40px; 
}
.solution-card { 
    background-color: var(--bg-surface); 
    padding: 45px 35px; 
    border-radius: var(--radius-sm); 
    box-shadow: var(--shadow-md); 
    border: 1px solid var(--border-light);
    /* 模拟实体书的书脊效果 */
    border-left: 14px solid var(--primary-color);
    transition: var(--transition);
    position: relative;
}
/* 交替使用书脊颜色，像书架上的一排书 */
.solution-card:nth-child(2n) { border-left-color: var(--secondary-color); }
.solution-card:nth-child(3n) { border-left-color: var(--text-muted); }

.solution-card:hover { 
    transform: translateY(-8px) rotate(-1deg); 
    box-shadow: var(--shadow-lg); 
}

.solution-card h3 { 
    font-size: 1.4rem; 
    margin-bottom: 15px;
    color: var(--primary-color); 
    font-family: var(--font-heading);
}
.solution-card p { color: var(--text-muted); font-size: 1rem; line-height: 1.7; }

/* --- 纯CSS 绘制图书/出版行业相关图标 (覆盖原本的科技图标) --- */
.solution-icon { 
    width: 60px; height: 60px; 
    margin-bottom: 30px; 
    position: relative; 
    color: var(--accent-color);
}
.solution-icon::before, .solution-icon::after { 
    content: ''; position: absolute; box-sizing: border-box; 
}
/* 原云服务 -> 翻开的诗集 */
.icon-cloud::before { 
    width: 26px; height: 34px; border: 2px solid currentColor;
    border-right: 1px solid currentColor; border-radius: 4px 0 0 4px;
    top: 15px; left: 4px; transform: skewY(-12deg);
}
.icon-cloud::after { 
    width: 26px; height: 34px; border: 2px solid currentColor;
    border-left: 1px solid currentColor; border-radius: 0 4px 4px 0;
    top: 15px; left: 30px; transform: skewY(12deg);
}

/* 原数据 -> 堆叠的古典名著 */
.icon-data::before { 
    width: 44px; height: 10px; border: 2px solid currentColor; 
    top: 14px; left: 8px; border-radius: 2px;
    box-shadow: 0 14px 0 -2px var(--bg-surface), 0 14px 0 0 currentColor,
                0 28px 0 -2px var(--bg-surface), 0 28px 0 0 currentColor;
}
.icon-data::after { /* 侧边书签线 */
    width: 4px; height: 14px; background: var(--secondary-color);
    top: 12px; left: 16px; box-shadow: 0 28px 0 0 var(--secondary-color);
}

/* 原AI -> 蘸水笔与墨水痕 */
.icon-ai::before {
    width: 20px; height: 20px; border: 2px solid currentColor; border-radius: 2px 2px 10px 10px;
    bottom: 5px; left: 20px; /* 墨水瓶 */
}
.icon-ai::after {
    width: 24px; height: 34px; border-left: 2px solid currentColor; border-bottom: 2px solid currentColor;
    border-radius: 0 0 0 100%; top: -5px; left: 30px; transform: rotate(25deg); /* 羽毛笔 */
}

/* 原安全防护 -> 藏书签 */
.icon-security::before { 
    width: 26px; height: 42px; border: 2px solid currentColor; border-bottom: none;
    top: 5px; left: 17px; background: var(--bg-surface); z-index: 2;
}
.icon-security::after {
    width: 18.5px; height: 18.5px; border-right: 2px solid currentColor; border-top: 2px solid currentColor;
    top: 36.5px; left: 20.5px; transform: rotate(45deg); background: var(--bg-surface); z-index: 1;
}

/* 原物联网 -> 阅读老花镜 */
.icon-iot::before { 
    width: 20px; height: 20px; border: 2px solid currentColor; border-radius: 50%;
    top: 25px; left: 8px;
}
.icon-iot::after { 
    width: 20px; height: 20px; border: 2px solid currentColor; border-radius: 50%;
    top: 25px; left: 32px; box-shadow: -10px -8px 0 -8px currentColor; /* 镜架桥 */
}

/* 原咨询 -> 经典信封 */
.icon-consult::before { 
    width: 44px; height: 30px; border: 2px solid currentColor; border-radius: 2px;
    top: 15px; left: 8px;
}
.icon-consult::after { 
    width: 31px; height: 31px; border-bottom: 2px solid currentColor; border-right: 2px solid currentColor;
    top: -2px; left: 14.5px; transform: rotate(45deg);
}

/* --- 5. 关于我们 (叠纸视觉艺术) --- */
#about { background-color: var(--bg-surface); }
#about .about-content { display: flex; align-items: center; gap: 70px; }
.about-text { flex: 1; }
.about-text h3 { font-size: 1.8rem; margin-bottom: 1.5rem; font-family: var(--font-heading); }
.about-text p { margin-bottom: 1.5rem; color: var(--text-muted); font-size: 1.1rem; text-indent: 2em; }
.about-action { margin-top: 3rem; }

/* 纯CSS生成的实体书籍层叠摆放视觉 */
.about-visual {
    flex: 1; 
    height: 400px; 
    background: var(--primary-color);
    border-radius: 4px;
    display: flex; align-items: center; justify-content: center;
    position: relative; 
    /* 模拟底下压着的另外两本书 */
    box-shadow: 
        15px 15px 0 0 var(--secondary-color),
        30px 30px 0 0 #D4CDBB,
        40px 40px 30px rgba(0,0,0,0.1);
    transform: translate(-15px, -15px);
}
.about-visual::before {
    content: ''; position: absolute;
    width: calc(100% - 40px); height: calc(100% - 40px);
    border: 1px solid rgba(255,255,255,0.2);
}
.about-visual span { 
    z-index: 1; 
    color: var(--bg-surface); 
    font-size: 2rem; 
    font-weight: 700; 
    font-family: var(--font-heading);
    letter-spacing: 5px;
    writing-mode: vertical-rl; /* 竖排文字，彰显传统出版之美 */
    text-shadow: 2px 2px 0 var(--secondary-color);
}

/* --- 6. 资讯/新书发布列表区 --- */
#news, #content { background-color: var(--bg-body); }
.news-grid { 
    display: grid; 
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); 
    gap: 40px; 
}
.news-card {
    background-color: var(--bg-surface); 
    border-radius: var(--radius-sm); 
    box-shadow: var(--shadow-sm);
    display: flex; flex-direction: column; 
    transition: var(--transition);
    border: 1px solid var(--border-light);
    position: relative;
    overflow: hidden; 
}
.news-card:hover { 
    transform: translateY(-5px); 
    box-shadow: var(--shadow-lg); 
}

/* 如果没有封面图，使用纯CSS渲染出复古书籍封面的质感 */
.news-cover {
    height: 240px; width: 100%; 
    position: relative;
    background-color: var(--border-light);
    display: flex; align-items: center; justify-content: center;
    border-bottom: 4px solid var(--border-dark);
}
/* 利用CSS制作精装封皮纹理 */
.news-card:nth-child(3n+1) .news-cover { background: repeating-linear-gradient(45deg, #1E2B3C, #1E2B3C 10px, #16202D 10px, #16202D 20px); }
.news-card:nth-child(3n+2) .news-cover { background: repeating-linear-gradient(-45deg, #8B2626, #8B2626 10px, #7A2020 10px, #7A2020 20px); }
.news-card:nth-child(3n+3) .news-cover { background: repeating-linear-gradient(0deg, #4A5D4E, #4A5D4E 10px, #3E4E41 10px, #3E4E41 20px); }

.news-cover img {
    width: 100%; height: 100%; object-fit: cover; display: block;
    transition: transform 0.6s ease;
}
.news-card:hover .news-cover img { transform: scale(1.03); }

.news-content { padding: 30px; flex-grow: 1; display: flex; flex-direction: column; background: var(--bg-surface); }
.news-meta { font-size: 0.9rem; color: var(--text-muted); margin-bottom: 15px; display: flex; gap: 10px; font-family: var(--font-heading); }
.news-meta a { color: var(--secondary-color); font-weight: 600;}
.news-meta a:hover { text-decoration: underline; }

.news-content h4 { font-size: 1.3rem; margin-bottom: 15px; line-height: 1.5; font-family: var(--font-heading); }

.news-content p { flex-grow: 1; margin-bottom: 25px; font-size: 1rem; color: var(--text-muted); line-height: 1.7; }
.read-more-link { 
    font-weight: 700; font-size: 0.95rem; align-self: flex-start; 
    border-bottom: 2px solid var(--accent-color);
    padding-bottom: 3px;
}
.read-more-link:hover { border-color: var(--secondary-color); }

/* --- 7. FAQ 出版商答疑面板 --- */
#faq { background-color: var(--bg-surface); }
.faq-accordion { max-width: 800px; margin: 0 auto; display: flex; flex-direction: column; gap: 20px; }
.faq-item { 
    background: var(--bg-body);
    border: 1px solid var(--border-dark);
    border-radius: var(--radius-sm);
    box-shadow: 2px 2px 0 0 var(--border-light);
    overflow: hidden;
}
.faq-question {
    width: 100%; background: none; border: none; text-align: left; padding: 25px 30px;
    font-size: 1.15rem; font-weight: 700; cursor: pointer; display: flex;
    justify-content: space-between; align-items: center; color: var(--primary-color);
    font-family: var(--font-heading);
    transition: background 0.3s ease;
}
.faq-question:hover { background-color: var(--border-light); }
/* 展开符号设计为古朴的加减号 */
.faq-question::after { 
    content: '+'; 
    font-size: 1.5rem;
    font-weight: 400;
    color: var(--secondary-color);
    transition: transform 0.3s ease;
}
.faq-item.active .faq-question::after { content: '−'; }
.faq-answer { 
    max-height: 0; overflow: hidden; transition: max-height 0.5s ease; 
    background-color: var(--bg-surface);
}
.faq-answer p {
    color: var(--text-main); font-size: 1.05rem; line-height: 1.8; padding: 25px 30px; margin: 0;
    border-top: 1px dashed var(--border-light);
}

/* --- 8. Footer 经典页脚 --- */
.main-footer { 
    background-color: #111822; /* 极黑夜读色 */
    color: #A39E93; 
    padding: 80px 0 30px; 
    margin-top: auto; 
    border-top: 8px solid var(--secondary-color); 
}
.footer-content { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 40px; margin-bottom: 60px; }
.footer-column { flex: 1; min-width: 220px; }
.footer-column h4 { 
    color: var(--accent-color); 
    margin-bottom: 1.8rem; 
    font-size: 1.3rem; 
    font-family: var(--font-heading);
    border-bottom: 1px solid rgba(197, 160, 89, 0.3);
    padding-bottom: 10px;
    display: inline-block;
}
.footer-column p { font-size: 0.95rem; line-height: 1.8; }
.footer-column ul { list-style: none; }
.footer-column ul li { margin-bottom: 15px; }
.footer-column ul li a { color: #A39E93; font-size: 1rem; }
.footer-column ul li a:hover { color: var(--bg-surface); }
.footer-bottom { 
    text-align: center; padding-top: 30px; 
    border-top: 1px solid rgba(255,255,255,0.05); 
    font-size: 0.9rem; font-family: var(--font-heading);
}

/* --- 9. 内容阅读页 (极致的沉浸式书籍排版) --- */
.page-container { padding: 60px 0 100px; background-color: var(--bg-body); }

/* 收窄阅读宽度，符合名著最佳单行字数 */
.single-post-wrapper { 
    max-width: 740px; 
    margin: 0 auto; 
    background: var(--bg-surface); 
    padding: 60px 70px; 
    border-radius: 2px; 
    border: 1px solid var(--border-dark); 
    /* 模拟一本书翻开的厚度 */
    box-shadow: 
        3px 3px 0 0 var(--bg-body),
        4px 4px 0 0 var(--border-dark),
        15px 15px 30px rgba(0,0,0,0.06); 
}

.breadcrumb { padding-bottom: 25px; font-size: 0.95rem; color: var(--text-muted); margin-bottom: 30px; font-family: var(--font-heading); border-bottom: 1px dashed var(--border-light); }
.breadcrumb a { font-weight: 600;}
.breadcrumb span { margin: 0 12px; color: var(--border-dark); }

.page-header { text-align: left; margin-bottom: 40px; }
.center-header { text-align: center; margin-bottom: 50px; }
.page-header h1 { font-size: 2.8rem; color: var(--primary-color); letter-spacing: 1px; line-height: 1.3; }
.page-meta { color: var(--text-muted); font-size: 1rem; margin-top: 20px; font-family: var(--font-heading); }
.page-meta a { font-weight: 600;}
.page-meta a:hover { text-decoration: underline; }

/* Markdown 文章正文优化：首字下沉与衬线体阅读 */
.markdown-body { 
    color: var(--text-main); 
    font-size: 1.15rem; 
    line-height: 2; 
    word-wrap: break-word; 
    font-family: var(--font-heading); /* 正文全部切换为传统衬线字体 */
    text-align: justify; /* 两端对齐，书籍排版标准 */
}

/* 经典的首字下沉设计 (Drop Cap) */
.markdown-body > p:first-of-type::first-letter {
    font-size: 4rem;
    float: left;
    margin-top: 0.15em;
    margin-right: 0.15em;
    margin-bottom: -0.1em;
    line-height: 0.8;
    color: var(--secondary-color);
    font-weight: 900;
}

.markdown-body h2 { font-size: 1.8rem; margin: 3rem 0 1.5rem; color: var(--primary-color); border-bottom: 1px solid var(--border-dark); padding-bottom: 10px; }
.markdown-body h2::after { display: none; }
.markdown-body h3 { font-size: 1.5rem; margin: 2.5rem 0 1rem; color: var(--primary-color); }
.markdown-body p { margin-bottom: 1.8rem; }
.markdown-body ul, .markdown-body ol { padding-left: 2em; margin-bottom: 1.8rem; color: var(--text-main); }
.markdown-body li { margin-bottom: 0.5rem; }
.markdown-body img { max-width: 100%; height: auto; border: 4px solid var(--bg-body); outline: 1px solid var(--border-dark); margin: 2.5rem auto; box-shadow: var(--shadow-sm); display: block; }
/* 引用块设计为书中的题记 */
.markdown-body blockquote { 
    border: none;
    border-top: 2px solid var(--secondary-color);
    border-bottom: 2px solid var(--secondary-color);
    background-color: transparent; 
    padding: 30px; margin: 3rem 0; 
    color: var(--text-muted); 
    font-style: italic;
    text-align: center;
    font-size: 1.25rem;
}
.markdown-body a { text-decoration: underline; text-decoration-color: rgba(139, 38, 38, 0.3); text-underline-offset: 4px;}
.markdown-body a:hover { text-decoration-color: var(--secondary-color); }
.markdown-body hr { border: 0; height: 1px; background: none; border-top: 1px dashed var(--border-dark); margin: 3.5rem 0; text-align: center; }
.markdown-body hr::after { content: '❖'; position: relative; top: -14px; background: var(--bg-surface); padding: 0 15px; color: var(--border-dark); font-size: 1.2rem; }

/* 代码块保持整洁 */
.markdown-body pre { background: var(--bg-body); color: var(--text-main); padding: 25px; border: 1px solid var(--border-dark); border-radius: var(--radius-sm); overflow-x: auto; margin-bottom: 2.5rem; font-size: 0.95rem; font-family: monospace; }
.markdown-body code { font-family: ui-monospace, SFMono-Regular, Consolas, monospace; background: var(--border-light); padding: 2px 6px; border-radius: 2px; color: var(--secondary-color); }
.markdown-body pre code { background: none; color: inherit; padding: 0; }

/* 标签区：像书签或丝带 */
.post-tags { margin-top: 50px; padding-top: 30px; border-top: 1px solid var(--border-light); display: flex; flex-wrap: wrap; gap: 12px; }
.tag-pill { 
    display: inline-block; background: var(--bg-surface); padding: 6px 18px; 
    border-radius: 0; font-size: 0.9rem; font-weight: 600; font-family: var(--font-heading); 
    border: 1px solid var(--primary-color); 
}
.tag-pill:hover { background: var(--primary-color); color: var(--bg-surface); }

/* 上下一篇导航 */
.post-navigation { display: flex; justify-content: space-between; margin-top: 40px; padding-top: 40px; border-top: 3px double var(--border-light); }
.nav-next, .nav-prev { max-width: 45%; font-weight: 700; line-height: 1.5; font-family: var(--font-heading); font-size: 1.1rem; }
.nav-next span, .nav-prev span { display: block; font-size: 0.9rem; color: var(--text-muted); font-weight: 400; margin-bottom: 8px; font-family: var(--font-body); }
.nav-next { text-align: right; }

/* 翻页按钮：页码感 */
.pagination { display: flex; justify-content: center; align-items: center; gap: 10px; margin-top: 70px; }
.page-btn { 
    display: inline-flex; align-items: center; justify-content: center; 
    width: 44px; height: 44px; border: 1px solid var(--border-dark); 
    border-radius: 50%; background: var(--bg-surface); font-weight: 600; font-family: var(--font-heading);
}
.page-btn:hover { background-color: var(--primary-color); color: var(--bg-surface); border-color: var(--primary-color); }
.page-current { display: inline-flex; align-items: center; height: 44px; padding: 0 20px; font-weight: 700; font-family: var(--font-heading); color: var(--secondary-color); background: transparent; border: 1px solid var(--secondary-color); border-radius: 22px; }

/* 404 & 无内容 */
.error-page { text-align: center; padding: 120px 0; }
.error-page h1 { font-size: 8rem; color: var(--border-dark); margin-bottom: 20px; font-family: var(--font-heading); text-shadow: 4px 4px 0 var(--border-light); }
.error-page p { font-size: 1.3rem; margin-bottom: 40px; color: var(--text-main); font-family: var(--font-heading); }

.no-content { 
    grid-column: 1 / -1; 
    text-align: center; 
    padding: 80px 20px; 
    color: var(--text-muted); 
    background: var(--bg-surface); 
    border: 1px dashed var(--border-dark); 
    font-size: 1.1rem;
    font-family: var(--font-heading);
}

/* --- 10. 响应式适配 --- */
@media (max-width: 992px) { 
    h2 { font-size: 2.2rem; } 
    #hero h1 { font-size: 2.8rem; }
    .about-visual { height: 300px; transform: none; box-shadow: 10px 10px 0 0 var(--secondary-color); }
    .single-post-wrapper { padding: 50px 40px; }
    .logo { font-size: 1.3rem; } /* 修复：在平板尺寸下进一步缩小 Logo，防止溢出 */
    .main-nav ul li { margin-left: 12px; } /* 修复：缩小平板下的菜单间距 */
}

@media (max-width: 768px) {
    .main-header .container { height: 75px; }
    .logo { font-size: 1.4rem; }
    .menu-toggle { display: block; }
    
    .main-nav { 
        position: absolute; top: 75px; left: 0; width: 100%; 
        background-color: var(--bg-surface); flex-direction: column; 
        max-height: 0; overflow: hidden; transition: max-height 0.5s cubic-bezier(0.4, 0, 0.2, 1); 
        box-shadow: var(--shadow-md); border-top: 0px solid transparent; 
    }
    .main-nav.active { max-height: 500px; border-top: 1px solid var(--border-light); }
    .main-nav ul { flex-direction: column; padding: 0; }
    .main-nav ul li { margin: 0; border-bottom: 1px solid var(--border-light); text-align: center; }
    .main-nav ul li:last-child { border-bottom: none; }
    .main-nav ul li a { display: block; padding: 20px; font-size: 1.1rem; }
    .main-nav ul li a::after { display: none; }
    
    #hero { height: auto; padding: 100px 20px; }
    #hero h1 { font-size: 2.2rem; }
    #hero p { font-size: 1.05rem; }
    .hero-content { padding: 40px 20px; }
    
    #about .about-content { flex-direction: column; gap: 50px; }
    .footer-content { flex-direction: column; gap: 40px; }
    
    .single-post-wrapper { padding: 30px 20px; border-radius: 0; border-left: none; border-right: none; box-shadow: none; }
    .page-header h1 { font-size: 2.2rem; }
}

@media (max-width: 480px) { 
    section { padding: 70px 0; } 
    h2 { font-size: 1.9rem; margin-bottom: 3rem; } 
    .news-cover { height: 200px; }
    .page-header h1 { font-size: 1.8rem; }
    .markdown-body > p:first-of-type::first-letter { font-size: 3rem; }
    .post-navigation { flex-direction: column; gap: 30px; }
    .nav-next, .nav-prev { max-width: 100%; }
    .nav-next { text-align: left; }
}