/* 全局样式 */
:root {
  --primary-color: #2c3e50;
  --secondary-color: #3498db;
  --accent-color: #e74c3c;
  --light-color: #ecf0f1;
  --dark-color: #2c3e50;
}

body {
  font-family: 'Noto Sans SC', sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f9f9f9;
}

/* 导航栏 */
.navbar {
  background-color: var(--primary-color);
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.navbar-brand {
  font-weight: 700;
  color: white;
}

.nav-link {
  color: rgba(255,255,255,0.8);
  transition: color 0.3s;
}

.nav-link:hover {
  color: white;
}

/* 卡片样式 */
.team-card, .news-card, .feature {
  background: white;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  padding: 20px;
  margin-bottom: 20px;
  transition: transform 0.3s;
}

.team-card:hover, .news-card:hover {
  transform: translateY(-5px);
}

.team-card img {
  width: 100%;
  border-radius: 50%;
  margin-bottom: 15px;
}

/* 网格布局 */
.team-container, .research-features {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 20px;
}

/* 按钮样式 */
.button {
  display: inline-block;
  background-color: var(--secondary-color);
  color: white;
  padding: 10px 20px;
  border-radius: 4px;
  text-decoration: none;
  transition: background-color 0.3s;
}

.button:hover {
  background-color: #2980b9;
}

/* 响应式布局 */
@media (max-width: 768px) {
  .columns {
    flex-direction: column;
  }
  
  .team-container, .research-features {
    grid-template-columns: 1fr;
  }
}

/* 联系表单 */
.contact-form {
  background: white;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.form-group {
  margin-bottom: 15px;
}

.form-group label {
  display: block;
  margin-bottom: 5px;
  font-weight: 600;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 10px;
  border: 1px solid #ddd;
  border-radius: 4px;
}

.submit-btn {
  background-color: var(--accent-color);
  color: white;
  border: none;
  padding: 10px 20px;
  border-radius: 4px;
  cursor: pointer;
  transition: background-color 0.3s;
}

.submit-btn:hover {
  background-color: #c0392b;
}