body {
  background-color: #333;
  color: #fff;
}

.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 20px;
  text-align: center;
}

.nav1 {
  margin-bottom: 20px;
}

.nav1 a {
  display: inline-block;
  margin: 0 10px;
  padding: 10px 20px;
  border: none;
  border-radius: 5px;
  background-color: #2ecc71;
  cursor: pointer;
}

.nav2 {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
}

.nav2 a {
  margin: 10px;
  padding: 10px 20px;
  border: none;
  border-radius: 5px;
  background-color: #3498db;
  cursor: pointer;
}

a {
  display: inline-block;
  padding: 10px 20px;
  text-decoration: none;
  transition: background-color 0.3s ease;
  font-size: 16px;
  font-weight: bold;
  font-family: Arial, sans-serif;
}

a:hover {
  background-color: #e67e22;
}

footer {
  position: absolute; /* 将页脚定位在页面底部 */
  bottom: 0; /* 将页脚置于页面底部 */
  width: 100%; /* 设置页脚宽度为100% */
  height: 50px; /* 设置页脚高度 */
  display: flex; /* 使用弹性盒子布局 */
  justify-content: center; /* 将页脚内容居中对齐 */
  align-items: center; /* 将页脚内容垂直居中对齐 */
  font-size: 14px; /* 设置页脚文字大小 */
  color: #666; /* 设置页脚文字颜色 */
}