/* 全局样式 */
body {
  margin: 0;
  font-family: 'Source Sans Pro', sans-serif;
  line-height: 1.6;
  color: #F5F5F5;
  background: linear-gradient(135deg, #0A192F, #1E3A8A);
  overflow-x: hidden;
}

h1, h2, h3 {
  font-family: 'Poppins', sans-serif;
  letter-spacing: 1px;
}

a {
  color: #38BDF8;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 20px;
}

/* 视频背景与顶部提示 */
.header {
  position: relative;
  height: 400px;
  background: url('https://images.gptkong.com/demo/sample1.png') center/cover,
              linear-gradient(135deg, #0A192F, #1E3A8A);
  overflow: hidden;
}

.header::before {
  content: "这是一个网页样式设计参考";
  position: absolute;
  top: 20px;
  right: 20px;
  background: rgba(0, 0, 0, 0.6);
  color: #fff;
  padding: 10px 20px;
  border-radius: 5px;
  font-size: 14px;
}

/* 卡片式布局 */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 20px;
  margin: 40px 0;
}

.card {
  background: linear-gradient(135deg, #1E3A8A, #0A192F);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 10px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  overflow: hidden;
  position: relative;
}

.card:hover {
  transform: scale(1.05);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.3);
}

.card img {
  width: 100%;
  height: 150px;
  object-fit: cover;
}

.card-content {
  padding: 15px;
}

/* 文章展示区域 */
.article {
  background: rgba(0, 0, 0, 0.6);
  border-radius: 10px;
  padding: 20px;
  margin-bottom: 40px;
}

.article pre {
  background: #111111;
  color: #38BDF8;
  padding: 15px;
  border-radius: 5px;
  overflow-x: auto;
}

/* 动画效果 */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in {
  animation: fadeIn 1s ease-in-out;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .header {
    height: 300px;
  }

  .card-grid {
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  }

  .article pre {
    font-size: 14px;
  }
}