:root {
  --bg: #ffffff;
  --bg-soft: #f6f7f9;
  --text: #1a1a1a;
  --text-soft: #5c6470;
  --border: #e6e8eb;
  --accent: #2f6df6;
  --card: #ffffff;
  --shadow: 0 1px 3px rgba(0,0,0,.06), 0 8px 24px rgba(0,0,0,.04);
}
[data-theme="dark"] {
  --bg: #0f1115;
  --bg-soft: #16191f;
  --text: #e6e8eb;
  --text-soft: #9aa3af;
  --border: #262b33;
  --accent: #5b8bff;
  --card: #16191f;
  --shadow: 0 1px 3px rgba(0,0,0,.4), 0 8px 24px rgba(0,0,0,.3);
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.75;
  transition: background .2s ease, color .2s ease;
}
.container { max-width: 720px; margin: 0 auto; padding: 0 20px; }
.site-header { border-bottom: 1px solid var(--border); background: var(--bg); position: sticky; top: 0; z-index: 10; }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 60px; }
.logo { font-weight: 700; font-size: 18px; color: var(--text); text-decoration: none; }
.nav { display: flex; align-items: center; gap: 18px; }
.nav a { color: var(--text-soft); text-decoration: none; font-size: 15px; }
.nav a:hover { color: var(--accent); }
.theme-toggle { background: none; border: 1px solid var(--border); border-radius: 8px; width: 36px; height: 36px; cursor: pointer; font-size: 16px; color: var(--text); line-height: 1; }
.theme-toggle:hover { border-color: var(--accent); }
.intro { padding: 48px 0 24px; }
.intro h1 { font-size: 32px; margin: 0 0 12px; }
.intro p { color: var(--text-soft); font-size: 17px; margin: 0; }
.posts { display: flex; flex-direction: column; gap: 16px; padding: 24px 0 48px; }
.post-card { background: var(--card); border: 1px solid var(--border); border-radius: 14px; padding: 20px 22px; box-shadow: var(--shadow); transition: transform .15s ease, border-color .15s ease; }
.post-card a { text-decoration: none; color: inherit; display: block; }
.post-card:hover { transform: translateY(-2px); border-color: var(--accent); }
.post-card h2 { margin: 0 0 8px; font-size: 20px; }
.post-meta { display: flex; align-items: center; gap: 10px; font-size: 13px; color: var(--text-soft); margin-bottom: 8px; flex-wrap: wrap; }
.tag { background: var(--bg-soft); border: 1px solid var(--border); border-radius: 6px; padding: 1px 8px; font-size: 12px; }
.excerpt { margin: 0; color: var(--text-soft); font-size: 15px; }
.post { padding: 40px 0 48px; }
.back { display: inline-block; margin-bottom: 24px; color: var(--accent); text-decoration: none; font-size: 14px; }
.post h1 { font-size: 30px; margin: 0 0 12px; }
.post-content { font-size: 17px; }
.post-content p { margin: 16px 0; }
.post-content pre { background: var(--bg-soft); border: 1px solid var(--border); border-radius: 10px; padding: 16px; overflow: auto; }
.post-content code { font-family: "SF Mono", Consolas, "Courier New", monospace; font-size: 14px; }
.site-footer { border-top: 1px solid var(--border); padding: 24px 0; color: var(--text-soft); font-size: 14px; text-align: center; }
.md-body { font-size: 17px; }
.md-body h1 { font-size: 28px; margin: 24px 0 12px; }
.md-body h2 { font-size: 22px; margin: 24px 0 10px; border-bottom: 1px solid var(--border); padding-bottom: 6px; }
.md-body h3 { font-size: 18px; margin: 20px 0 8px; }
.md-body p { margin: 14px 0; }
.md-body ul, .md-body ol { padding-left: 24px; margin: 14px 0; }
.md-body li { margin: 6px 0; }
.md-body blockquote { margin: 14px 0; padding: 8px 16px; border-left: 4px solid var(--accent); background: var(--bg-soft); color: var(--text-soft); border-radius: 0 8px 8px 0; }
.md-body code { font-family: "SF Mono", Consolas, "Courier New", monospace; font-size: 14px; background: var(--bg-soft); padding: 2px 6px; border-radius: 4px; }
.md-body pre { background: var(--bg-soft); border: 1px solid var(--border); border-radius: 10px; padding: 16px; overflow: auto; }
.md-body pre code { background: none; padding: 0; }
.md-body a { color: var(--accent); }
.md-body img { max-width: 100%; border-radius: 10px; }
.md-body hr { border: none; border-top: 1px solid var(--border); margin: 24px 0; }