/* 全局样式设置 */
body {
  margin: 0;
  padding: 0;
  font-family: 'Roboto', sans-serif;
  background: linear-gradient(135deg, #1e3c72 70%, #2a5298 25%, #ff6600 5%);
  color: #333;
  line-height: 1.6;
}

/* 导航栏样式 */
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  background: rgba(30, 60, 114, 0.9);
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
  z-index: 1000;
}
.navbar ul {
  list-style: none;
  display: flex;
  justify-content: space-around;
  padding: 15px 0;
  margin: 0;
}
.navbar li {
  position: relative;
}
.navbar a {
  text-decoration: none;
  color: #fff;
  padding: 10px 15px;
  display: block;
  transition: background 0.3s;
}
.navbar a:hover {
  background: rgba(255, 255, 255, 0.1);
}
.navbar li ul {
  display: none;
  position: absolute;
  top: 40px;
  left: 0;
  background: rgba(42, 82, 152, 0.95);
  padding: 10px 0;
  border-radius: 4px;
}
.navbar li:hover ul {
  display: block;
}
.navbar li ul li {
  width: 150px;
}
.navbar li ul li a {
  padding: 10px 20px;
}

/* 主要内容区 */
.container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
  gap: 20px;
  padding: 100px 50px 50px 50px;
}
.card {
  background: #fff;
  border-radius: 10px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
  padding: 20px;
  transition: transform 0.3s, box-shadow 0.3s;
}
.card:hover {
  transform: translateY(-10px);
  box-shadow: 0 10px 15px rgba(0,0,0,0.2);
}
.card img {
  width: 100%;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
  transition: transform 0.3s;
}
.card img:hover {
  transform: scale(1.05);
}
.card-title {
  font-size: 1.5em;
  color: #1e3c72;
  margin-bottom: 10px;
}

/* 代码块样式 */
pre code {
  display: block;
  background: #f4f4f4;
  padding: 15px;
  border-radius: 5px;
  overflow: auto;
  position: relative;
}
pre code::before {
  content: "代码示例";
  position: absolute;
  top: -20px;
  left: 0;
  background: #1e3c72;
  color: #fff;
  padding: 5px 10px;
  border-radius: 3px;
  font-size: 0.9em;
}

/* 视差滚动背景 */
.parallax {
  background-image: url('https://images.gptkong.com/demo/sample1.png');
  height: 500px;
  background-attachment: fixed;
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
}

/* 加载动画 */
.loader {
  border: 8px solid #f3f3f3;
  border-top: 8px solid #1e3c72;
  border-radius: 50%;
  width: 60px;
  height: 60px;
  animation: spin 1s linear infinite;
  margin: 50px auto;
}
@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* 提示信息样式 */
.alert {
  background: rgba(255, 102, 0, 0.9);
  color: #fff;
  text-align: center;
  padding: 20px;
  font-size: 1.2em;
}

/* 图片样式 */
.decorative-image {
  width: 100%;
  border-radius: 10px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  transition: transform 0.3s, box-shadow 0.3s;
}
.decorative-image:hover {
  transform: scale(1.05);
  box-shadow: 0 8px 16px rgba(0,0,0,0.2);
}

/* 响应式调整 */
@media (max-width: 768px) {
  .navbar ul {
    flex-direction: column;
    align-items: center;
  }
  .navbar li ul {
    position: static;
  }
  .container {
    padding: 100px 20px 20px 20px;
  }
}