* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei",
    "PingFang SC", Arial, sans-serif;
  line-height: 1.7;
  color: #222;
  background: #f7f8fa;
}

a {
  color: #1f5fbf;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  width: min(1100px, 92%);
  margin: 0 auto;
}

/* 顶部导航 */
.site-header {
  background: #ffffff;
  border-bottom: 1px solid #e5e7eb;
  position: sticky;
  top: 0;
  z-index: 10;
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 0;
  gap: 24px;
}

.site-header h1 {
  margin: 0;
  font-size: 26px;
  letter-spacing: 0.5px;
}

.subtitle {
  margin: 4px 0 0;
  color: #666;
  font-size: 14px;
}

.nav {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
}

.nav a {
  color: #333;
  font-size: 15px;
}

.nav a:hover {
  color: #1f5fbf;
}

/* 首屏 */
.hero {
  display: grid;
  grid-template-columns: 1.7fr 0.9fr;
  gap: 32px;
  align-items: center;
  padding: 64px 0 40px;
}

.hero-text {
  background: #ffffff;
  padding: 40px;
  border-radius: 18px;
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.06);
}

.hero-text h2 {
  margin-top: 0;
  margin-bottom: 16px;
  font-size: 34px;
}

.hero-text p {
  color: #444;
  font-size: 17px;
}

.hero-links {
  margin-top: 28px;
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.button {
  display: inline-block;
  padding: 10px 18px;
  border-radius: 999px;
  background: #1f5fbf;
  color: #ffffff;
  font-weight: 600;
}

.button:hover {
  text-decoration: none;
  background: #164a96;
}

.button.secondary {
  background: #eef3ff;
  color: #1f5fbf;
}

.button.secondary:hover {
  background: #dfe9ff;
}

.profile-card {
  background: #ffffff;
  padding: 32px 24px;
  border-radius: 18px;
  text-align: center;
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.06);
}

.avatar {
  width: 120px;
  height: 120px;
  margin: 0 auto 20px;
  border-radius: 50%;
  background: linear-gradient(135deg, #dbeafe, #f1f5f9);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #64748b;
  font-weight: 600;
}

.profile-card h3 {
  margin: 10px 0 8px;
}

.profile-card p {
  margin: 6px 0;
  color: #666;
}

/* 通用区块 */
.section {
  background: #ffffff;
  margin: 28px 0;
  padding: 36px 40px;
  border-radius: 18px;
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.05);
}

.section h2 {
  margin-top: 0;
  margin-bottom: 20px;
  font-size: 26px;
  border-left: 5px solid #1f5fbf;
  padding-left: 12px;
}

.section p {
  color: #444;
}

/* 研究方向卡片 */
.grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.card {
  border: 1px solid #e5e7eb;
  border-radius: 14px;
  padding: 22px;
  background: #fbfdff;
}

.card h3 {
  margin-top: 0;
  margin-bottom: 10px;
  color: #111827;
}

.card p {
  margin-bottom: 0;
}

/* 项目经历 */
.timeline {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.timeline-item {
  padding-left: 18px;
  border-left: 3px solid #c7d2fe;
}

.timeline-item .time {
  display: inline-block;
  margin-bottom: 6px;
  color: #1f5fbf;
  font-weight: 600;
  font-size: 14px;
}

.timeline-item h3 {
  margin: 4px 0 8px;
}

/* 论文 */
.publication-list {
  padding-left: 22px;
}

.publication-list li {
  margin-bottom: 14px;
}

/* 联系方式 */
.contact-list {
  list-style: none;
  padding-left: 0;
}

.contact-list li {
  margin-bottom: 10px;
}

/* 页脚 */
.site-footer {
  margin-top: 40px;
  padding: 24px 0;
  color: #777;
  text-align: center;
  font-size: 14px;
}

/* 移动端适配 */
@media (max-width: 768px) {
  .header-content {
    flex-direction: column;
    align-items: flex-start;
  }

  .nav {
    gap: 12px;
  }

  .hero {
    grid-template-columns: 1fr;
    padding-top: 36px;
  }

  .hero-text {
    padding: 28px;
  }

  .hero-text h2 {
    font-size: 28px;
  }

  .section {
    padding: 28px;
  }

  .grid {
    grid-template-columns: 1fr;
  }
}