/* 极简主义黑白主题 - 遵循系统主题 */
:root {
  --bg-color: #ffffff;
  --text-color: #1a1a1a;
  --text-secondary: #666666;
  --border-color: #e0e0e0;
  --quote-bg: #f8f8f8;
  --link-color: #333333;
  --accent-color: #000000;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg-color: #121212;
    --text-color: #e8e8e8;
    --text-secondary: #999999;
    --border-color: #333333;
    --quote-bg: #1e1e1e;
    --link-color: #cccccc;
    --accent-color: #ffffff;
  }
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Newsreader', Georgia, 'Times New Roman', serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.8;
  font-size: 18px;
  transition: background-color 0.3s, color 0.3s;
}

/* 导航栏 */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: var(--bg-color);
  border-bottom: 1px solid var(--border-color);
  padding: 12px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 1000;
  backdrop-filter: blur(10px);
  background: rgba(var(--bg-color), 0.9);
}

.nav-title {
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}

.nav-controls {
  display: flex;
  gap: 16px;
  align-items: center;
}

.lang-btn, .mindmap-link {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-color);
  padding: 6px 14px;
  font-size: 13px;
  cursor: pointer;
  transition: all 0.2s;
  text-decoration: none;
  font-family: inherit;
}

.lang-btn:hover, .mindmap-link:hover {
  background: var(--text-color);
  color: var(--bg-color);
}

/* 主容器 */
.container {
  max-width: 680px;
  margin: 0 auto;
  padding: 100px 24px 80px;
}

/* 封面区域 */
.cover {
  margin-bottom: 48px;
}

.cover-image {
  width: 100%;
  height: auto;
  margin-bottom: 32px;
}

.title {
  font-size: 42px;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 24px;
  letter-spacing: -0.5px;
}

.meta {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 16px;
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.meta a {
  color: var(--text-secondary);
  text-decoration: none;
}

.meta a:hover {
  text-decoration: underline;
}

.divider {
  height: 1px;
  background: var(--border-color);
  margin: 48px 0;
}

/* 文章内容 */
.content p {
  margin-bottom: 24px;
}

.content h2 {
  font-size: 28px;
  font-weight: 600;
  margin: 56px 0 24px;
  line-height: 1.3;
}

.content h3 {
  font-size: 22px;
  font-weight: 600;
  margin: 40px 0 20px;
}

.content ul, .content ol {
  margin-bottom: 24px;
  padding-left: 28px;
}

.content li {
  margin-bottom: 12px;
}

.content blockquote {
  background: var(--quote-bg);
  border-left: 3px solid var(--accent-color);
  padding: 20px 24px;
  margin: 32px 0;
  font-style: italic;
}

.content a {
  color: var(--link-color);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.content a:hover {
  text-decoration-thickness: 2px;
}

.content img {
  width: 100%;
  height: auto;
  margin: 32px 0;
}

.content strong {
  font-weight: 600;
}

.content em {
  font-style: italic;
}

/* 语言切换 */
.lang-en, .lang-zh {
  display: none;
}

body.en .lang-en {
  display: block;
}

body.zh .lang-zh {
  display: block;
}

body.en .lang-en.inline,
body.zh .lang-zh.inline {
  display: inline;
}

/* 签名 */
.signature {
  margin-top: 48px;
  font-style: italic;
}

/* 统计 */
.stats {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
  font-size: 14px;
  color: var(--text-secondary);
}

.stats-grid {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
}

/* 页脚 */
.footer {
  margin-top: 80px;
  padding: 24px 0;
  border-top: 1px solid var(--border-color);
  text-align: center;
  font-size: 14px;
  color: var(--text-secondary);
}

/* 响应式 */
@media (max-width: 640px) {
  .title {
    font-size: 32px;
  }
  
  .content h2 {
    font-size: 24px;
  }
  
  .container {
    padding: 80px 16px 60px;
  }
  
  .nav {
    padding: 10px 16px;
  }
  
  body {
    font-size: 17px;
  }
}

/* 滚动条 */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-color);
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-secondary);
}