/* 芦苇 Reed 博客 —— GitHub Markdown 风格
 * 白底 + 灰边框 + 蓝色链接,参照 github.com 的 README 渲染观感 */

:root {
  --bg: #ffffff;
  --text: #1f2328;
  --muted: #59636e;
  --border: #d0d7de;
  --cell-bg: #f6f8fa;
  --accent: #0969da;
  --code-bg: rgba(175, 184, 193, 0.2);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans",
          "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC",
          Helvetica, Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
          "Liberation Mono", monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.5;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

.container { max-width: 1080px; margin: 0 auto; padding: 0 24px; }

/* 所有链接默认无下划线;仅正文里的链接悬停时加下划线(GitHub README 风格)。
   导航、目录、品牌、上一篇/下一篇等 UI 链接始终无下划线。 */
a { color: var(--accent); text-decoration: none; }
.markdown-content a:hover { text-decoration: underline; }
.post-nav a:hover { text-decoration: none; }

img { max-width: 100%; }

/* ---- 顶部导航 ---- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}
.site-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}
.site-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  color: var(--text);
}
.site-brand:hover { text-decoration: none; }
.site-brand img { border-radius: 4px; }
.nav-links {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: 20px;
}
.nav-links a { color: var(--muted); font-size: 14px; }
.nav-links a:hover { color: var(--text); text-decoration: none; }
.nav-links a.active { color: var(--accent); font-weight: 600; }

/* ---- Markdown 正文:GitHub 观感 ---- */
/* flex: 1 让正文撑满剩余高度,内容短时 footer 贴到视口底部 */
.markdown-body { flex: 1 0 auto; padding: 32px 0 48px; }

.markdown-body h1,
.markdown-body h2 {
  padding-bottom: 0.3em;
  border-bottom: 1px solid var(--border);
}
.markdown-body h1 { font-size: 2em; margin: 0.67em 0 0.5em; }
.markdown-body h2 { font-size: 1.5em; margin: 1.5em 0 0.75em; }
.markdown-body h3 { font-size: 1.25em; margin: 1.4em 0 0.7em; }
.markdown-body h4 { font-size: 1em; margin: 1.2em 0 0.6em; }
.markdown-body h5 { font-size: 0.875em; margin: 1em 0 0.5em; }
.markdown-body h1, .markdown-body h2, .markdown-body h3, .markdown-body h4 {
  scroll-margin-top: 72px;
}
.markdown-body p { margin: 0 0 16px; }
.markdown-body ul, .markdown-body ol { padding-left: 2em; margin: 0 0 16px; }
.markdown-body li { margin: 4px 0; }
.markdown-body blockquote {
  margin: 0 0 16px;
  padding: 0 1em;
  color: var(--muted);
  border-left: 4px solid var(--border);
}
.markdown-body table {
  display: block;
  width: 100%;
  max-width: 100%;
  overflow: auto;
  margin: 0 0 16px;
  border-collapse: collapse;
}
.markdown-body th, .markdown-body td {
  border: 1px solid var(--border);
  padding: 6px 13px;
}
.markdown-body th { background: var(--cell-bg); font-weight: 600; }
.markdown-body tr:nth-child(2n) { background: var(--cell-bg); }
.markdown-body code {
  font-family: var(--mono);
  font-size: 85%;
  background: var(--code-bg);
  border-radius: 6px;
  padding: 0.2em 0.4em;
}
.markdown-body pre {
  margin: 0 0 16px;
  padding: 16px;
  background: var(--cell-bg);
  border-radius: 6px;
  overflow: auto;
}
.markdown-body pre code {
  background: none;
  padding: 0;
  border-radius: 0;
}
/* 标题本身带分割线(h1/h2 底部边框),正文里的 --- 分割线不再显示 */
.markdown-body hr {
  display: none;
}

/* ---- 文章页布局 ---- */
.post-header { margin-bottom: 24px; }
.post-header h1 {
  font-size: 1.7em;
  margin: 0 0 8px;
  padding: 0;
  border-bottom: none;
}
.post-meta { color: var(--muted); font-size: 14px; margin: 0; }
.post-meta .tags { margin-left: 6px; }
.tag {
  display: inline-block;
  padding: 0.15em 0.6em;
  margin-right: 6px;
  font-size: 12px;
  font-weight: 500;
  color: var(--muted);
  background: var(--cell-bg);
  border: 1px solid var(--border);
  border-radius: 999px;
}

.markdown-content { min-width: 0; }

@media (min-width: 1024px) {
  .markdown-body {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 260px;
    gap: 40px;
    align-items: start;
  }
  .markdown-body > .markdown-content { order: 1; }
  .markdown-body > .toc { order: 2; }
}

/* ---- 目录 ---- */
.toc { align-self: start; font-size: 14px; }
.toc-list { list-style: none; margin: 0; padding: 0; }
.toc-list ol { list-style: none; margin: 0; padding-left: 12px; }
.toc-list li { margin: 2px 0; }
.toc-list a {
  display: block;
  padding: 3px 8px;
  color: var(--muted);
  border-left: 2px solid transparent;
  border-radius: 4px;
  line-height: 1.5;
}
.toc-list a:hover { color: var(--text); text-decoration: none; }
.toc-list a.active {
  color: var(--accent);
  background: var(--cell-bg);
  border-left-color: var(--accent);
}
.toc-h2 { font-weight: 600; }

.toc-toggle { display: none; }
@media (min-width: 1024px) {
  .toc {
    position: sticky;
    top: 72px;
    max-height: calc(100vh - 88px);
    overflow-y: auto;
  }
}
@media (max-width: 1023.98px) {
  .toc {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 0;
  }
  .toc-toggle {
    display: block;
    width: 100%;
    border: none;
    background: none;
    font: inherit;
    font-weight: 600;
    padding: 8px 12px;
    cursor: pointer;
    text-align: left;
    color: var(--text);
  }
  .toc .toc-list { display: none; padding: 0 12px 8px; }
  .toc.open .toc-list { display: block; }
}

/* ---- 上一篇/下一篇 ---- */
.post-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}
.post-nav-item {
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 12px 16px;
}
.post-nav-item:only-child { grid-column: 1 / -1; }
.post-nav-label { display: block; color: var(--muted); font-size: 12px; margin-bottom: 4px; }
.post-nav-item a { color: var(--text); }
.post-nav-item a:hover { color: var(--accent); text-decoration: none; }

/* ---- 页脚 ---- */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 24px 0;
  text-align: center;
  color: var(--muted);
  font-size: 14px;
}
.site-footer p { margin: 4px 0; }
.site-footer a { color: var(--muted); }

@media (max-width: 600px) {
  .markdown-body h1 { font-size: 1.6em; }
  .post-nav { grid-template-columns: 1fr; }
}