:root {
  --text: #2d2d2d;
  --muted: #888;
  --line: #e6e6e6;
  --accent: #4a6fa5;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  line-height: 1.8;
  background: #fff;
}

.wrap { max-width: 720px; margin: 0 auto; padding: 0 20px; }

.site-header {
  border-bottom: 1px solid var(--line);
  background: #fff;
  position: sticky;
  top: 0;
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}

.logo {
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
  text-decoration: none;
  letter-spacing: 1px;
}

nav a {
  color: var(--muted);
  text-decoration: none;
  margin-left: 18px;
  font-size: 14px;
}

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

.hero { padding: 56px 0 32px; }

.hero h1 { font-size: 28px; margin-bottom: 10px; }

.hero p { color: var(--muted); }

.posts { padding-bottom: 40px; }

.posts h2 { font-size: 16px; color: var(--muted); margin-bottom: 20px; font-weight: 500; }

.post-item {
  border-bottom: 1px solid var(--line);
  padding: 18px 0;
}

.post-item h3 { font-size: 18px; margin-bottom: 4px; }

.post-item h3 a { color: var(--text); text-decoration: none; }

.post-item h3 a:hover { color: var(--accent); }

.post-item time { font-size: 13px; color: var(--muted); }

.post-item p { margin-top: 8px; color: var(--muted); font-size: 14px; }

.post-content { padding: 40px 0 60px; }

.post-content h1 { font-size: 26px; margin-bottom: 8px; }

.post-content time { color: var(--muted); font-size: 14px; }

.post-content h2 {
  font-size: 20px;
  margin: 28px 0 12px;
  padding-left: 10px;
  border-left: 3px solid var(--accent);
}

.post-content p { margin: 14px 0; }

.site-footer {
  border-top: 1px solid var(--line);
  padding: 22px 0;
  color: var(--muted);
  font-size: 13px;
}

@media (max-width: 560px) {
  .hero h1 { font-size: 22px; }
}