:root {
  --primary: #1a365d;
  --accent: #2b6cb0;
  --text: #2d3748;
  --bg: #ffffff;
  --border: #e2e8f0;
  --light-bg: #f7fafc;
}

* { box-sizing: border-box; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--text);
  line-height: 1.6;
  margin: 0;
  background: var(--bg);
}

.container {
  max-width: 840px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
}

/* 统一顶部导航栏 */
.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1.5px solid var(--border);
  padding-bottom: 1rem;
  margin-bottom: 2rem;
}

.nav-brand {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
}

.nav-links {
  display: flex;
  gap: 1.2rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--accent);
  font-weight: 600;
  border-bottom: 2px solid var(--accent);
}

/* 通用元素排版 */
h1 { color: var(--primary); margin: 0 0 0.5rem; font-size: 1.8rem; }
h2 { color: var(--primary); border-bottom: 1.5px solid var(--border); padding-bottom: 0.3rem; margin-top: 2rem; font-size: 1.3rem; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* 论文与卡片样式 */
.pub-item, .card {
  padding: 1rem;
  margin-bottom: 1.2rem;
  background: var(--light-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
}
.pub-title { font-weight: 600; color: #1a202c; }
.pub-authors { color: #4a5568; font-size: 0.95rem; margin: 0.2rem 0; }
.pub-venue { font-style: italic; color: #718096; font-size: 0.9rem; }
.pub-links a { font-size: 0.85rem; font-weight: 500; margin-right: 0.8rem; }

/* 按钮 */
.btn {
  display: inline-block;
  background: var(--primary);
  color: #fff !important;
  padding: 0.45rem 1rem;
  border-radius: 6px;
  font-size: 0.9rem;
  margin-top: 0.5rem;
}
.btn:hover { background: #2c5282; text-decoration: none; }

footer {
  margin-top: 3.5rem;
  font-size: 0.85rem;
  color: #a0aec0;
  text-align: center;
  border-top: 1px solid var(--border);
  padding-top: 1.5rem;
}