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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: #333;
  background: #f9f9f9;
  line-height: 1.7;
}

a { color: #4a90d9; text-decoration: none; }
a:hover { color: #2c6fad; }

/* Header */
header {
  background: #fff;
  border-bottom: 1px solid #eee;
  padding: 0 2rem;
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.site-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: #222;
  letter-spacing: 0.02em;
}

nav a {
  margin-left: 1.5rem;
  font-size: 0.95rem;
  color: #555;
}
nav a:hover { color: #4a90d9; }

/* Hero */
.hero {
  background: linear-gradient(135deg, #4a90d9 0%, #6c63ff 100%);
  color: #fff;
  text-align: center;
  padding: 5rem 2rem 4rem;
}
.hero h1 { font-size: 2.4rem; font-weight: 800; margin-bottom: 0.8rem; }
.hero p { font-size: 1.1rem; opacity: 0.9; }

/* Main layout */
.container { max-width: 900px; margin: 0 auto; padding: 2.5rem 1.5rem; }

/* Cards */
.section-title {
  font-size: 1.3rem;
  font-weight: 700;
  color: #222;
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid #4a90d9;
  display: inline-block;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.2rem;
  margin-bottom: 3rem;
}

.card {
  background: #fff;
  border-radius: 10px;
  padding: 1.4rem 1.5rem;
  box-shadow: 0 2px 8px rgba(0,0,0,0.06);
  transition: transform 0.2s, box-shadow 0.2s;
}
.card:hover { transform: translateY(-3px); box-shadow: 0 6px 18px rgba(0,0,0,0.1); }

.card-tag {
  display: inline-block;
  font-size: 0.72rem;
  background: #eef4ff;
  color: #4a90d9;
  border-radius: 4px;
  padding: 2px 8px;
  margin-bottom: 0.6rem;
  font-weight: 600;
  letter-spacing: 0.03em;
}

.card h3 { font-size: 1rem; margin-bottom: 0.4rem; color: #222; }
.card p { font-size: 0.88rem; color: #666; }
.card .read-more { font-size: 0.82rem; margin-top: 0.8rem; display: inline-block; }

/* About */
.about-box {
  background: #fff;
  border-radius: 10px;
  padding: 2rem;
  box-shadow: 0 2px 8px rgba(0,0,0,0.06);
  margin-bottom: 3rem;
  display: flex;
  gap: 2rem;
  align-items: flex-start;
}
.about-avatar {
  width: 80px; height: 80px;
  border-radius: 50%;
  background: linear-gradient(135deg, #4a90d9, #6c63ff);
  display: flex; align-items: center; justify-content: center;
  font-size: 2rem; color: #fff; flex-shrink: 0;
}
.about-info h2 { font-size: 1.1rem; margin-bottom: 0.4rem; }
.about-info p { font-size: 0.9rem; color: #555; margin-bottom: 0.3rem; }
.about-info a { font-size: 0.88rem; }

/* Footer */
footer {
  text-align: center;
  padding: 2rem;
  font-size: 0.82rem;
  color: #aaa;
  border-top: 1px solid #eee;
  background: #fff;
}

/* Article page */
.article-wrap { max-width: 720px; margin: 0 auto; padding: 2.5rem 1.5rem; }
.article-wrap h1 { font-size: 1.8rem; margin-bottom: 0.5rem; }
.article-meta { font-size: 0.82rem; color: #999; margin-bottom: 2rem; }
.article-body h2 { font-size: 1.2rem; margin: 1.8rem 0 0.6rem; color: #222; }
.article-body p { margin-bottom: 1rem; color: #444; }
.article-body code {
  background: #f0f4ff; border-radius: 4px;
  padding: 2px 6px; font-size: 0.88em; color: #c0392b;
}
.article-body pre {
  background: #1e1e2e; color: #cdd6f4;
  border-radius: 8px; padding: 1.2rem;
  overflow-x: auto; margin: 1rem 0;
  font-size: 0.88rem; line-height: 1.6;
}
.article-body pre code { background: none; color: inherit; padding: 0; }
.back-link { display: inline-block; margin-bottom: 1.5rem; font-size: 0.9rem; }

@media (max-width: 600px) {
  .hero h1 { font-size: 1.6rem; }
  .about-box { flex-direction: column; gap: 1rem; }
  header { padding: 0 1rem; }
  .site-title { font-size: 1rem; }
}