/* ============================================
   极简个人博客 - 全局样式
   风格：Notion/Bear 笔记式纯净阅读体验
   ============================================ */

/* --- Reset & Base --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-bg: #ffffff;
  --color-text: #1a1a1a;
  --color-text-secondary: #6b7280;
  --color-border: #e5e7eb;
  --color-accent: #2563eb;
  --color-accent-hover: #1d4ed8;
  --color-code-bg: #f6f8fa;
  --color-quote-border: #d1d5db;
  --color-tag-bg: #f3f4f6;
  --color-tag-text: #374151;
  --font-sans: -apple-system, "BlinkMacSystemFont", "Segoe UI", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono", "Noto Sans Mono", monospace;
  --max-width: 720px;
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover {
  color: var(--color-accent-hover);
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
}

/* --- Layout --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

/* --- Navigation --- */
.nav {
  padding: var(--spacing-xl) 0;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--spacing-2xl);
}

.nav-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-brand {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
}

.nav-brand:hover {
  text-decoration: none;
  color: var(--color-text);
}

.nav-links {
  display: flex;
  gap: var(--spacing-lg);
  list-style: none;
}

.nav-links a {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-text);
}

/* --- Footer --- */
.footer {
  margin-top: var(--spacing-2xl);
  padding: var(--spacing-lg) 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
  color: var(--color-text-secondary);
  font-size: 0.85rem;
}

/* --- 首页 - 文章列表 --- */
.home-header {
  margin-bottom: var(--spacing-xl);
}

.home-header h1 {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: var(--spacing-sm);
}

.home-header p {
  color: var(--color-text-secondary);
}

.post-list {
  list-style: none;
}

.post-item {
  padding: var(--spacing-lg) 0;
  border-bottom: 1px solid var(--color-border);
}

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

.post-item h2 {
  font-size: 1.35rem;
  font-weight: 600;
  margin-bottom: var(--spacing-xs);
  line-height: 1.4;
}

.post-item h2 a {
  color: var(--color-text);
}

.post-item h2 a:hover {
  color: var(--color-accent);
  text-decoration: none;
}

.post-meta {
  color: var(--color-text-secondary);
  font-size: 0.85rem;
  margin-bottom: var(--spacing-sm);
}

.post-excerpt {
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin-bottom: var(--spacing-sm);
}

.read-more {
  font-size: 0.9rem;
  font-weight: 500;
}

/* --- 文章详情页 --- */
.article-header {
  margin-bottom: var(--spacing-xl);
}

.article-header h1 {
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: var(--spacing-sm);
}

.article-meta {
  color: var(--color-text-secondary);
  font-size: 0.85rem;
}

.article-tags {
  display: inline-flex;
  gap: var(--spacing-sm);
  margin-left: var(--spacing-md);
}

.article-tags a {
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  padding: 2px 10px;
  border-radius: 4px;
  font-size: 0.8rem;
}

.article-tags a:hover {
  background: var(--color-border);
  text-decoration: none;
}

/* 正文排版 */
.content {
  font-size: 1rem;
  line-height: 1.8;
}

.content h2 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-top: var(--spacing-xl);
  margin-bottom: var(--spacing-md);
  line-height: 1.4;
}

.content h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-sm);
}

.content p {
  margin-bottom: var(--spacing-md);
}

.content ul,
.content ol {
  margin-bottom: var(--spacing-md);
  padding-left: var(--spacing-lg);
}

.content li {
  margin-bottom: var(--spacing-xs);
}

.content blockquote {
  border-left: 3px solid var(--color-quote-border);
  padding-left: var(--spacing-md);
  margin: var(--spacing-md) 0;
  color: var(--color-text-secondary);
  font-style: italic;
}

.content code {
  font-family: var(--font-mono);
  background: var(--color-code-bg);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.9em;
}

.content pre {
  background: var(--color-code-bg);
  padding: var(--spacing-md);
  border-radius: 8px;
  overflow-x: auto;
  margin: var(--spacing-md) 0;
  font-size: 0.9rem;
  line-height: 1.6;
}

.content pre code {
  background: none;
  padding: 0;
  font-size: inherit;
}

.content hr {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: var(--spacing-xl) 0;
}

.content img {
  border-radius: 8px;
  margin: var(--spacing-md) 0;
}

.content a {
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* 文章底部导航 */
.article-nav {
  margin-top: var(--spacing-2xl);
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: space-between;
}

.article-nav a {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
}

.article-nav a:hover {
  color: var(--color-accent);
}

.back-link {
  display: inline-block;
  margin-top: var(--spacing-lg);
  font-size: 0.9rem;
}

/* --- 标签页 --- */
.page-header {
  margin-bottom: var(--spacing-xl);
}

.page-header h1 {
  font-size: 2rem;
  font-weight: 700;
}

.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-xl);
}

.tag-cloud a {
  background: var(--color-tag-bg);
  color: var(--color-tag-text);
  padding: 4px 14px;
  border-radius: 20px;
  font-size: 0.85rem;
}

.tag-cloud a:hover {
  background: var(--color-border);
  text-decoration: none;
}

.tag-section {
  margin-bottom: var(--spacing-xl);
}

.tag-section h2 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  padding-bottom: var(--spacing-sm);
  border-bottom: 1px solid var(--color-border);
}

.tag-section ul {
  list-style: none;
}

.tag-section li {
  padding: var(--spacing-sm) 0;
}

.tag-section li time {
  color: var(--color-text-secondary);
  font-size: 0.85rem;
  margin-right: var(--spacing-sm);
}

/* --- 归档页 --- */
.archive-year {
  margin-bottom: var(--spacing-xl);
}

.archive-year h2 {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: var(--spacing-md);
}

.archive-month {
  margin-bottom: var(--spacing-lg);
}

.archive-month h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-sm);
}

.archive-month ul {
  list-style: none;
}

.archive-month li {
  padding: var(--spacing-xs) 0;
}

.archive-month li time {
  color: var(--color-text-secondary);
  font-size: 0.85rem;
  margin-right: var(--spacing-sm);
}

/* --- 关于页 --- */
.about-content {
  display: flex;
  gap: var(--spacing-xl);
  align-items: flex-start;
  margin-bottom: var(--spacing-xl);
}

.about-avatar {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  background: var(--color-tag-bg);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
}

.about-text {
  flex: 1;
}

.about-text p {
  margin-bottom: var(--spacing-md);
}

.social-links {
  list-style: none;
  display: flex;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.social-links a {
  color: var(--color-text-secondary);
  font-size: 0.9rem;
}

/* --- 响应式 --- */
@media (max-width: 600px) {
  .nav-inner {
    flex-direction: column;
    gap: var(--spacing-md);
  }

  .home-header h1,
  .article-header h1,
  .page-header h1 {
    font-size: 1.5rem;
  }

  .about-content {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .social-links {
    justify-content: center;
  }

  .article-nav {
    flex-direction: column;
    gap: var(--spacing-sm);
  }
}