/* 免疫疗法博客 - 专业医疗科技风格 */
:root {
    --primary: #0d9488;
    --primary-dark: #0f766e;
    --primary-light: #14b8a6;
    --secondary: #06b6d4;
    --accent: #22d3ee;
    --bg-dark: #0c1222;
    --bg-card: #111827;
    --bg-card-hover: #1f2937;
    --text-primary: #f0fdfa;
    --text-secondary: #99f6e4;
    --text-muted: #5eead4;
    --border: #134e4a;
    --gradient: linear-gradient(135deg, #0d9488 0%, #06b6d4 50%, #22d3ee 100%);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    font-family: 'Segoe UI', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.7;
    min-height: 100vh;
}
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* 导航栏 */
.navbar {
    position: fixed; top: 0; left: 0; right: 0;
    background: rgba(12, 18, 34, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    z-index: 1000; padding: 16px 0;
}
.nav-container { display: flex; justify-content: space-between; align-items: center; max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.nav-logo {
    font-size: 1.5rem; font-weight: 700;
    background: var(--gradient);
    -webkit-background-clip: text; background-clip: text;
    -webkit-text-fill-color: transparent;
    text-decoration: none;
}
.nav-links { display: flex; gap: 32px; list-style: none; }
.nav-links a { color: var(--text-secondary); text-decoration: none; font-weight: 500; transition: color 0.3s; }
.nav-links a:hover { color: var(--text-primary); }

/* 英雄区 */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(180deg, rgba(13, 148, 136, 0.15) 0%, transparent 100%);
    text-align: center;
}
.hero h1 {
    font-size: 3rem; font-weight: 800; margin-bottom: 20px;
    background: var(--gradient);
    -webkit-background-clip: text; background-clip: text;
    -webkit-text-fill-color: transparent;
}
.hero .subtitle { font-size: 1.2rem; color: var(--text-secondary); max-width: 600px; margin: 0 auto; }

/* 分类网格 */
.section-title { font-size: 1.8rem; font-weight: 700; margin-bottom: 30px; color: var(--text-primary); }
.categories-grid, .article-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 24px;
    margin-bottom: 60px;
}

/* 分类卡片 */
.category-card, .article-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    overflow: hidden;
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}
.category-card:hover, .article-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary);
    box-shadow: 0 20px 40px rgba(13, 148, 136, 0.2);
}
.card-header {
    padding: 30px;
    background: var(--gradient);
    text-align: center;
}
.card-icon { font-size: 2.5rem; margin-bottom: 12px; display: block; }
.card-title { font-size: 1.3rem; font-weight: 700; color: white; }
.card-body { padding: 20px; }
.card-desc { color: var(--text-secondary); font-size: 0.95rem; line-height: 1.6; }

/* 文章卡片 */
.article-image {
    height: 140px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
}
.article-image span { font-size: 3rem; }
.article-content { padding: 20px; }
.article-tag {
    display: inline-block;
    padding: 4px 12px;
    background: rgba(13, 148, 136, 0.2);
    color: var(--primary-light);
    border-radius: 20px;
    font-size: 0.8rem;
    margin-bottom: 12px;
}
.article-content h3 { font-size: 1.1rem; margin-bottom: 10px; color: var(--text-primary); }
.article-content p { color: var(--text-secondary); font-size: 0.9rem; }

/* 文章详情 */
.article-detail { padding: 120px 0 60px; }
.article-header { text-align: center; margin-bottom: 40px; }
.article-header .tag {
    display: inline-block;
    padding: 6px 16px;
    background: rgba(13, 148, 136, 0.2);
    color: var(--primary-light);
    border-radius: 20px;
    font-size: 0.9rem;
    margin-bottom: 20px;
}
.article-header h1 { font-size: 2.2rem; margin-bottom: 16px; color: var(--text-primary); }
.article-header .meta { color: var(--text-muted); font-size: 0.95rem; }
.article-body {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
}
.article-body h2 {
    font-size: 1.5rem;
    color: var(--primary-light);
    margin: 40px 0 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--border);
}
.article-body h3 { font-size: 1.2rem; color: var(--text-primary); margin: 30px 0 15px; }
.article-body p { margin-bottom: 20px; color: var(--text-secondary); line-height: 1.8; }
.article-body ul, .article-body ol { margin: 20px 0; padding-left: 30px; }
.article-body li { margin-bottom: 10px; color: var(--text-secondary); }
.article-body blockquote {
    background: rgba(13, 148, 136, 0.1);
    border-left: 4px solid var(--primary);
    padding: 20px;
    margin: 30px 0;
    border-radius: 0 12px 12px 0;
}
.article-body blockquote p { margin: 0; color: var(--text-primary); }

/* 面包屑 */
.breadcrumb {
    padding: 100px 0 20px;
    color: var(--text-muted);
    font-size: 0.9rem;
}
.breadcrumb a { color: var(--text-secondary); text-decoration: none; }
.breadcrumb a:hover { color: var(--primary-light); }
.breadcrumb span { margin: 0 8px; }

/* 外链区域 */
.external-links { padding: 60px 0; background: var(--bg-card); margin-top: 60px; }
.external-links h3 { font-size: 1.3rem; margin-bottom: 24px; color: var(--text-primary); text-align: center; }
.links-container { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; }
.links-container a {
    padding: 8px 16px;
    background: var(--bg-dark);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.85rem;
    transition: all 0.3s;
}
.links-container a:hover {
    border-color: var(--primary);
    color: var(--primary-light);
    transform: translateY(-2px);
}

/* 页脚 */
.footer {
    background: var(--bg-card);
    border-top: 1px solid var(--border);
    padding: 40px 0;
    text-align: center;
}
.footer-content p { color: var(--text-muted); margin-bottom: 16px; }
.footer-links { display: flex; gap: 24px; justify-content: center; }
.footer-links a { color: var(--text-secondary); text-decoration: none; }
.footer-links a:hover { color: var(--primary-light); }

/* 响应式 */
@media (max-width: 768px) {
    .hero h1 { font-size: 2rem; }
    .nav-links { display: none; }
    .categories-grid, .article-grid { grid-template-columns: 1fr; }
}