/* 全局变量定义 */
:root {
  --primary-green: #2E7D32; /* 主色：代表自然环保 */
  --secondary-blue: #BBDEFB; /* 辅色：象征科技未来 */
  --neutral-gray: #F5F5F5; /* 中性色：过渡色 */
  --accent-color: #FFD700; /* 点缀色：吸引视线 */
  --font-title: 'Roboto Bold', sans-serif; /* 标题字体 */
  --font-text: 'Open Sans', sans-serif; /* 正文字体 */
}

/* 基本样式重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* body样式设置 */
body {
  background: linear-gradient(135deg, var(--neutral-gray), var(--secondary-blue));
  color: var(--primary-green);
  font-family: var(--font-text);
  line-height: 1.6;
  padding: 20px;
}

/* 导航栏样式 */
.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 40px;
  background: var(--primary-green);
  position: fixed;
  top: 0;
  width: 100%;
  transition: background 0.5s ease;
  z-index: 1000;
}

.navbar.scrolled {
  background: var(--secondary-blue);
}

.navbar a {
  color: white;
  text-decoration: none;
  margin-left: 20px;
  font-size: 1rem;
  transition: color 0.3s;
}

.navbar a:hover {
  color: var(--accent-color);
}

/* 主要内容容器 */
.container {
  max-width: 1200px;
  margin: 100px auto 50px auto; /* 确保导航栏不遮挡内容 */
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  padding: 0 20px;
}

/* 文章样式 */
article {
  background: white;
  padding: 30px;
  border-radius: 10px;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

article h2, article h3 {
  font-family: var(--font-title);
  color: var(--primary-green);
}

article h2 {
  font-size: 2rem;
  margin-bottom: 20px;
}

article h3 {
  font-size: 1.5rem;
  margin-top: 30px;
  margin-bottom: 15px;
}

article p {
  font-size: 1rem;
  margin-bottom: 15px;
  color: #333;
}

article pre {
  background: #f0f0f0;
  padding: 15px;
  border-radius: 5px;
  overflow-x: auto;
  margin-bottom: 20px;
}

article code {
  font-family: 'Courier New', Courier, monospace;
  color: var(--primary-green);
}

/* 提示信息样式 */
.notice {
  text-align: center;
  font-size: 1.2rem;
  color: var(--accent-color);
  margin-bottom: 40px;
  font-weight: bold;
}

/* 图片样式 */
img.decorative {
  width: 100%;
  max-width: 320px;
  border-radius: 10px;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  transition: transform 0.3s, box-shadow 0.3s;
}

img.decorative:hover {
  transform: scale(1.05);
  box-shadow: 0 8px 16px rgba(0,0,0,0.2);
}

/* 响应式布局 */
@media (min-width: 768px) {
  .container {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1200px) {
  .container {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* 按钮样式 */
.button {
  background-color: var(--primary-green);
  color: white;
  padding: 10px 20px;
  border: none;
  border-radius: 25px;
  cursor: pointer;
  transition: background-color 0.3s, transform 0.2s;
  font-size: 1rem;
}

.button:hover {
  background-color: darken(var(--primary-green), 10%);
  transform: translateY(-2px);
}

/* 折叠区域样式 */
.collapsible {
  background-color: var(--neutral-gray);
  color: #333;
  cursor: pointer;
  padding: 18px;
  width: 100%;
  border: none;
  text-align: left;
  outline: none;
  font-size: 1rem;
  transition: background-color 0.3s;
}

.collapsible:hover {
  background-color: lighten(var(--neutral-gray), 10%);
}

.content {
  padding: 0 18px;
  display: none;
  overflow: hidden;
  background-color: white;
}

/* 底部样式 */
.footer {
  background: var(--secondary-blue);
  color: white;
  padding: 20px 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-top: 2px solid var(--primary-green);
}

.footer .language-switcher button {
  background: none;
  border: 1px solid white;
  color: white;
  padding: 8px 16px;
  border-radius: 20px;
  cursor: pointer;
  transition: background-color 0.3s, color 0.3s;
  font-size: 0.9rem;
}

.footer .language-switcher button:hover {
  background-color: white;
  color: var(--secondary-blue);
}

.footer .chat-window {
  background-color: var(--primary-green);
  color: white;
  padding: 15px 25px;
  border-radius: 50px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
  cursor: pointer;
  transition: transform 0.3s, background-color 0.3s;
}

.footer .chat-window:hover {
  transform: scale(1.1);
  background-color: darken(var(--primary-green), 10%);
}