:root {
  --accent: #2f6df6;
  --accent-soft: #eaf1fe;
  --text: #1f2937;
  --muted: #6b7280;
  --bg: #f7f8fa;
  --card: #ffffff;
  --border: #e5e7eb;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.75;
}

.wrap {
  max-width: 880px;
  margin: 0 auto;
  padding: 0 20px;
}

/* 顶栏 */
.site-header {
  background: #fff;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.brand {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text);
  text-decoration: none;
  letter-spacing: .5px;
}

.brand::before {
  content: "📘 ";
}

nav a {
  margin-left: 20px;
  color: var(--muted);
  text-decoration: none;
  font-size: .95rem;
}

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

/* 主体 */
main { padding-bottom: 40px; }

.hero { padding: 54px 0 10px; }

.hero h1 {
  font-size: 2.2rem;
  margin: 0 0 14px;
  letter-spacing: 1px;
}

.hero p {
  color: var(--muted);
  font-size: 1.02rem;
  max-width: 640px;
  margin: 0;
}

h2 {
  font-size: 1.25rem;
  margin: 40px 0 16px;
  padding-left: 12px;
  border-left: 4px solid var(--accent);
}

h3 { font-size: 1.05rem; }

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

/* 卡片 */
.cards {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  transition: box-shadow .15s ease, transform .15s ease;
}

.card:hover {
  box-shadow: 0 6px 18px rgba(31, 41, 55, .07);
  transform: translateY(-2px);
}

.card a {
  display: block;
  padding: 18px 20px;
  text-decoration: none;
  color: inherit;
}

.card h3 { margin: 0 0 6px; }
.card p { margin: 0; color: var(--muted); font-size: .9rem; }

.tag {
  display: inline-block;
  background: var(--accent-soft);
  color: var(--accent);
  border-radius: 999px;
  padding: 1px 10px;
  font-size: .78rem;
  margin-bottom: 8px;
}

/* 文章 / 信息块 */
article.note,
.panel {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 22px 26px;
  margin-bottom: 18px;
}

article.note h3 { margin-top: 0; }

article.note pre {
  background: #0f172a;
  color: #e2e8f0;
  border-radius: 8px;
  padding: 14px 16px;
  overflow-x: auto;
  font-size: .85rem;
  line-height: 1.6;
}

article.note code {
  background: var(--accent-soft);
  border-radius: 4px;
  padding: 1px 6px;
  font-size: .88em;
}

article.note pre code { background: none; padding: 0; }

.info-list { margin: 0; padding: 0; list-style: none; }
.info-list li {
  display: flex;
  gap: 12px;
  padding: 8px 0;
  border-bottom: 1px dashed var(--border);
  font-size: .95rem;
}
.info-list li:last-child { border-bottom: none; }
.info-list .label { color: var(--muted); min-width: 96px; }

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

/* 页脚 */
.site-footer {
  margin-top: 30px;
  padding: 26px 0;
  background: #fff;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: .86rem;
  text-align: center;
}

.site-footer p { margin: 4px 0; }

.site-footer a {
  color: var(--muted);
  text-decoration: none;
}

.site-footer a:hover { color: var(--accent); }

@media (max-width: 640px) {
  nav a { margin-left: 12px; font-size: .9rem; }
  .hero { padding: 36px 0 6px; }
  .hero h1 { font-size: 1.7rem; }
}