/* ====== 简洁现代风，视频教程页面 ====== */
body {
  margin: 0;
  padding: 0;
  font-family: "Microsoft YaHei", sans-serif;
  background: #f4f7f6;
  color: #333;
}
.navbar {
  background: #4CAF50; /* 绿色导航栏 */
  padding: 10px 20px;
}
.navbar ul {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  justify-content: center;
}
.navbar li {
  margin: 0 15px;
}
.navbar a {
  color: #fff;
  text-decoration: none;
  font-weight: bold;
  font-size: 16px;
}
/* 页面主体 */
.container {
  max-width: 960px;
  margin: 20px auto;
  padding: 20px;
  background: #fff;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.container h1 {
  text-align: center;
  color: #2e7d32; /* 深绿色标题 */
  margin-bottom: 10px;
}
.container > p {
  text-align: center;
  color: #666;
  margin-bottom: 30px;
}
.video-section {
  margin-bottom: 40px;
  text-align: center;
}
.video-section h2 {
  color: #388e3c; /* 中绿色标题 */
  margin-bottom: 15px;
}
.video-section video {
  width: 100%;
  max-width: 700px;
  height: auto;
  border: 1px solid #ddd;
  border-radius: 4px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}
.video-section p {
  margin-top: 10px;
  color: #555;
}
.text-section h2 {
  color: #388e3c;
  margin-bottom: 15px;
}
.text-section ul {
  list-style: disc;
  margin-left: 20px;
  line-height: 1.8;
}
.text-section ul li {
  margin-bottom: 8px;
}
.text-section ul li strong {
  color: #2e7d32;
}
/* 底部版权 */
.footer {
  text-align: center;
  font-size: 12px;
  color: #999;
  padding: 20px;
}

/* ====== 响应式设计 ====== */
@media (max-width: 768px) {
  .navbar ul {
    flex-direction: column;
    align-items: center;
  }
  
  .navbar li {
    margin: 5px 0;
  }
  
  .container {
    margin: 10px;
    padding: 15px;
  }
  
  .container h1 {
    font-size: 24px;
  }
  
  .video-section h2 {
    font-size: 20px;
  }
  
  .video-section video {
    max-width: 500px;
  }
  
  .text-section h2 {
    font-size: 20px;
  }
}

@media (max-width: 480px) {
  .container {
    margin: 5px;
    padding: 10px;
  }
  
  .container h1 {
    font-size: 20px;
  }
  
  .video-section h2 {
    font-size: 18px;
  }
  
  .video-section video {
    max-width: 350px;
  }
  
  .video-section p {
    font-size: 14px;
  }
  
  .text-section h2 {
    font-size: 18px;
  }
  
  .text-section ul {
    margin-left: 15px;
    font-size: 14px;
  }
}

.text-section ul li {
  margin-bottom: 8px;
}
.text-section ul li strong {
  color: #2e7d32;
}
/* 底部版权 */
.footer {
  text-align: center;
  font-size: 12px;
  color: #999;
  padding: 20px;
}