:root {
  --bg: #f3f7f4;
  --surface: #ffffff;
  --text: #1a2420;
  --muted: #5f6d66;
  --border: #d7e3db;
  --accent: #1f7a4c;
  --accent-soft: #e5f4eb;
  --shadow: 0 8px 24px rgba(26, 36, 32, 0.06);
  --radius: 14px;
  --max: 960px;
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  min-height: 100%;
  font-family: var(--font);
  color: var(--text);
  background:
    radial-gradient(1200px 500px at 10% -10%, #d9efe2 0%, transparent 55%),
    radial-gradient(900px 400px at 100% 0%, #e8f1ea 0%, transparent 50%),
    var(--bg);
}

a {
  color: inherit;
  text-decoration: none;
}

.site-header {
  max-width: var(--max);
  margin: 0 auto;
  padding: 36px 20px 12px;
}

.brand {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.brand-sub {
  margin-top: 8px;
  color: var(--muted);
  font-size: 0.95rem;
}

.site-main {
  max-width: var(--max);
  margin: 0 auto;
  padding: 12px 20px 64px;
}

.post-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.post-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform 0.15s ease, border-color 0.15s ease;
}

.post-card:hover {
  transform: translateY(-2px);
  border-color: #cfd8d3;
}

.post-card h2 {
  margin: 0;
  font-size: 1.15rem;
  line-height: 1.4;
}

.post-meta {
  color: var(--muted);
  font-size: 0.85rem;
}

.post-summary {
  margin: 0;
  color: #4a4641;
  font-size: 0.95rem;
  line-height: 1.6;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: auto;
}

.tag {
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.75rem;
}

.empty-state {
  padding: 48px 24px;
  text-align: center;
  background: var(--surface);
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  color: var(--muted);
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-bottom: 20px;
  color: var(--accent);
  font-size: 0.95rem;
}

.article {
  padding: 28px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.article h1 {
  margin: 0 0 12px;
  font-size: 1.8rem;
  line-height: 1.35;
}

.article-body {
  margin-top: 24px;
  line-height: 1.8;
  font-size: 1.02rem;
}

.article-body h2,
.article-body h3 {
  margin-top: 1.6em;
  margin-bottom: 0.6em;
}

.article-body p,
.article-body ul,
.article-body ol {
  margin: 0 0 1em;
}

.article-body code {
  padding: 0.1em 0.35em;
  border-radius: 4px;
  background: #f0ece4;
  font-size: 0.92em;
}

.article-body pre {
  padding: 14px;
  overflow: auto;
  border-radius: 10px;
  background: #1f2421;
  color: #f4f1ea;
}

.article-body pre code {
  padding: 0;
  background: transparent;
  color: inherit;
}

.article-body a {
  color: var(--accent);
  text-decoration: underline;
}

.site-footer {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 20px 40px;
  color: var(--muted);
  font-size: 0.85rem;
}

.error-box {
  padding: 24px;
  border-radius: var(--radius);
  background: #fff4f1;
  border: 1px solid #f0cfc6;
  color: #7a3b2e;
}

@media (max-width: 720px) {
  .post-grid {
    grid-template-columns: 1fr;
  }

  .article {
    padding: 20px;
  }

  .article h1 {
    font-size: 1.45rem;
  }
}