/* 引入Google字体 */
@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;600&family=Roboto:wght@400;700&display=swap');

/* CSS变量定义 */
:root {
  --primary-color: #0D1B2A; /* 主背景色 */
  --secondary-color: #162447; /* 渐变过渡色 */
  --highlight-color: #38FF5C; /* 高亮色 */
  --neon-green: #38FF5C;
  --electric-blue: #00F5FF;
  --text-color: #FFFFFF;
  --background-gradient: linear-gradient(to bottom, #0D1B2A, #162447);
  --card-background: rgba(255, 255, 255, 0.1);
  --card-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
  --font-family: 'Roboto', 'Poppins', sans-serif;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background: var(--background-gradient);
  color: var(--text-color);
  font-family: var(--font-family);
  line-height: 1.6;
  letter-spacing: 0.5px;
  transition: background 0.5s ease, color 0.5s ease;
}

/* 全屏沉浸式设计 */
header {
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center center/cover;
  position: relative;
}

header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--background-gradient);
  opacity: 0.8;
}

/* 标题样式 */
header h1 {
  z-index: 1;
  font-size: 3rem;
  color: var(--electric-blue);
  text-align: center;
  text-shadow: 0 0 10px var(--neon-green), 0 0 20px var(--electric-blue);
}

/* 主要内容区 */
main {
  padding: 60px 20px;
  max-width: 1200px;
  margin: 0 auto;
}

/* 三列网格布局 */
.grid-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
}

/* 卡片式布局 */
.card {
  background-color: var(--card-background);
  border-radius: 10px;
  padding: 20px;
  box-shadow: var(--card-shadow);
  backdrop-filter: blur(10px);
  position: relative;
  overflow: hidden;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(56, 255, 92, 0.2), transparent 70%);
  animation: float 10s infinite linear;
}

@keyframes float {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.card:hover {
  transform: scale(1.05);
  box-shadow: 0 8px 16px rgba(56, 255, 92, 0.5);
}

/* 代码块样式 */
pre {
  background-color: rgba(255,255,255,0.1);
  padding: 15px;
  border-radius: 5px;
  overflow-x: auto;
  font-family: 'Courier New', Courier, monospace;
}

code {
  color: var(--highlight-color);
}

/* 表格样式 */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
}

th, td {
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 10px;
  text-align: left;
}

th {
  background-color: rgba(56, 255, 92, 0.2);
}

td {
  background-color: rgba(255, 255, 255, 0.05);
}

/* 按钮样式 */
button {
  padding: 10px 20px;
  background-color: var(--highlight-color);
  color: var(--primary-color);
  border: none;
  border-radius: 5px;
  cursor: pointer;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

button:hover {
  transform: scale(1.1);
  box-shadow: 0 8px 16px rgba(56, 255, 92, 0.5);
}

/* 导航栏 */
nav {
  position: fixed;
  top: 0;
  width: 100%;
  background-color: rgba(0, 0, 0, 0.7);
  padding: 15px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 1000;
}

nav a {
  color: var(--text-color);
  text-decoration: none;
  margin: 0 10px;
  transition: color 0.3s ease;
}

nav a:hover {
  color: var(--highlight-color);
}

/* 图片样式 */
img {
  width: 100%;
  border-radius: 10px;
  margin: 10px 0;
  transition: transform 0.3s ease;
}

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

/* 提示信息 */
.alert {
  background-color: rgba(255, 255, 255, 0.1);
  padding: 10px 20px;
  border-left: 5px solid var(--highlight-color);
  margin: 20px 0;
  border-radius: 3px;
}

/* 响应式设计 */
@media (max-width: 1440px) {
  header h1 {
    font-size: 2.5rem;
  }
}

@media (max-width: 1200px) {
  main {
    padding: 40px 15px;
  }

  .card {
    padding: 15px;
  }
}

@media (max-width: 1024px) {
  .grid-container {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  }
}

@media (max-width: 768px) {
  nav {
    flex-direction: column;
  }

  .grid-container {
    grid-template-columns: 1fr;
  }

  header h1 {
    font-size: 2rem;
  }
}

@media (max-width: 480px) {
  header h1 {
    font-size: 1.5rem;
    text-align: center;
  }

  nav a {
    margin: 5px 0;
  }
}

@media (max-width: 320px) {
  header h1 {
    font-size: 1.2rem;
  }

  main {
    padding: 20px 10px;
  }
}