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

/* 基本字体设置 */
body {
  font-family: 'Roboto', sans-serif;
  font-size: 16px;
  color: #FFFFFF;
  background: linear-gradient(135deg, #1E3A8A, #3B82F6);
  line-height: 1.6;
}

/* 主要容器 */
.container {
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 0;
}

/* 导航栏样式 */
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  background-color: rgba(30, 58, 138, 0.9);
  padding: 20px 0;
  z-index: 1000;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.navbar .nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.navbar .nav-logo {
  font-size: 1.5em;
  color: #FFFFFF;
  text-decoration: none;
}

.navbar ul {
  list-style: none;
  display: flex;
  gap: 20px;
}

.navbar ul li a {
  color: #FFFFFF;
  text-decoration: none;
  font-size: 1em;
  transition: color 0.3s, transform 0.3s;
}

.navbar ul li a:hover {
  color: #F97316;
  transform: scale(1.1);
}

/* 主视觉区块 */
.hero {
  height: 100vh;
  background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center center/cover;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.hero::after {
  content: "这是一个网页样式设计参考";
  position: absolute;
  bottom: 20px;
  right: 20px;
  background-color: rgba(255, 255, 255, 0.8);
  color: #1E3A8A;
  padding: 10px 20px;
  border-radius: 5px;
  font-size: 1.2em;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

/* 章节样式 */
section {
  padding: 60px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

section:last-child {
  border-bottom: none;
}

section h2 {
  font-size: 2em;
  color: #FFFFFF;
  margin-bottom: 20px;
  position: relative;
}

section h2::after {
  content: "";
  width: 50px;
  height: 4px;
  background: #F97316;
  display: block;
  margin-top: 10px;
  border-radius: 2px;
}

section p, section h3, section pre {
  color: #D1D5DB;
  margin-bottom: 20px;
}

section h3 {
  font-size: 1.5em;
  color: #10B981;
  margin-top: 30px;
}

section pre {
  background-color: rgba(255, 255, 255, 0.1);
  padding: 20px;
  border-radius: 8px;
  overflow-x: auto;
  font-size: 0.9em;
  line-height: 1.4;
}

/* 卡片布局 */
.card-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 20px;
}

.card {
  background-color: rgba(255, 255, 255, 0.1);
  border-radius: 10px;
  padding: 20px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  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(0,0,0,0.2);
  transition: transform 0.3s;
}

.card img:hover {
  transform: scale(1.05);
}

.card-content {
  margin-top: 15px;
}

.card-content h3 {
  font-size: 1.2em;
  color: #3B82F6;
  margin-bottom: 10px;
}

.card-content p {
  color: #D1D5DB;
  font-size: 1em;
}

/* 导航系统 */
.nav-sidebar {
  position: fixed;
  top: 80px;
  left: 20px;
  background-color: rgba(30, 58, 138, 0.8);
  padding: 20px;
  border-radius: 8px;
}

.nav-sidebar ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.nav-sidebar ul li a {
  color: #FFFFFF;
  text-decoration: none;
  font-size: 1em;
  transition: color 0.3s;
}

.nav-sidebar ul li a:hover {
  color: #F97316;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .navbar .nav-container {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .nav-sidebar {
    display: none;
  }
  
  .container {
    padding: 20px 0;
  }
}

@media (max-width: 480px) {
  body {
    font-size: 14px;
  }
  
  section h2 {
    font-size: 1.5em;
  }
  
  .navbar ul {
    flex-direction: column;
    gap: 10px;
  }
}