/* 全局样式 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  line-height: 1.6;
  color: #333;
  background-color: #f8f9fa;
  padding: 20px;
}

article {
  max-width: 800px;
  margin: 0 auto;
  background: white;
  padding: 40px;
  border-radius: 12px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

/* 标题样式 */
h1 {
  font-size: 2.5rem;
  color: #1a73e8;
  margin-bottom: 16px;
  text-align: center;
  font-weight: 700;
}

h2 {
  font-size: 1.5rem;
  color: #1a73e8;
  margin: 32px 0 16px;
  font-weight: 600;
}

h3 {
  font-size: 1.3rem;
  color: #1a73e8;
  margin: 24px 0 12px;
  padding-bottom: 8px;
  border-bottom: 2px solid #e0e0e0;
  font-weight: 600;
}

h4 {
  font-size: 1.1rem;
  color: #1a73e8;
  margin: 16px 0 8px;
  font-weight: 600;
}

/* 段落和列表样式 */
p {
  margin-bottom: 16px;
  text-align: justify;
}

ul, ol {
  margin: 16px 0;
  padding-left: 30px;
}

li {
  margin: 8px 0;
  line-height: 1.6;
}

ol li {
  list-style-type: decimal;
}

ul li {
  list-style-type: disc;
}

/* 链接样式 */
a {
  color: #1a73e8;
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: #0d47a1;
  text-decoration: underline;
}

/* 强调文本 */
strong {
  color: #d93025;
  font-weight: 700;
}

/* 脚注样式 */
footer {
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid #e0e0e0;
  color: #666;
  font-size: 0.9rem;
  text-align: center;
}

/* 响应式设计 */
@media (max-width: 768px) {
  article {
    padding: 20px;
    margin: 10px;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.3rem;
  }
}