/* 1. 浏览器样式重置（新增：浅蓝色背景） */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Microsoft YaHei", Arial, sans-serif;
}
html {
  scroll-behavior: smooth;
  font-size: 16px;
}
body {
  color: #333;
  background: #e6f7ff; /* 替换为浅蓝色 #e6f7ff（清爽商务风） */
  line-height: 1.6;
}
a {
  text-decoration: none;
  color: #165dff; /* 主色调不变，保持与浅蓝色背景的对比 */
  transition: all 0.3s ease;
}
a:hover {
  color: #0e4bdb;
}
ul, li {
  list-style: none;
}
img {
  display: block;
  max-width: 100%;
  height: auto;
  border: 0;
}
h1, h2, h3, h4 {
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 0.8rem;
}
h1 {
  font-size: 2rem;
  color: #222;
}
h2 {
  font-size: 1.8rem;
  color: #222;
}
h3 {
  font-size: 1.5rem;
}
h4 {
  font-size: 1.2rem;
}
p {
  margin-bottom: 1rem;
}
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}
.btn {
  display: inline-block;
  padding: 0.8rem 2rem;
  background: linear-gradient(90deg, #165dff, #0e4bdb);
  color: #fff !important;
  border-radius: 4px;
  font-size: 1rem;
  font-weight: 500;
  border: none;
  cursor: pointer;
  box-shadow: 0 2px 8px rgba(22, 93, 255, 0.3);
}
.btn:hover {
  box-shadow: 0 4px 12px rgba(22, 93, 255, 0.5);
  transform: translateY(-2px);
}
.seo-hidden {
  position: absolute;
  left: -9999px;
  top: -9999px;
  width: 1px;
  height: 1px;
  overflow: hidden;
}

/* 2. 头部导航（新增：背景色与浅蓝色协调） */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: #fff; /* 导航栏保持白色，避免与背景色混淆 */
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  z-index: 999;
  padding: 1rem 0;
  transition: all 0.3s ease;
}
.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.logo {
  width: 200px;
}
.nav-list {
  display: flex;
  gap: 2rem;
}
.nav-list a {
  color: #333;
  font-size: 1rem;
  font-weight: 500;
  padding: 0.5rem 0;
  border-bottom: 2px solid transparent;
}
.nav-list a:hover, .nav-list a.active {
  color: #165dff;
  border-bottom: 2px solid #165dff;
}
.menu-btn, .close-btn {
  display: none;
  width: 32px;
  height: 32px;
  cursor: pointer;
}

/* 3. 回到顶部按钮（新增：与背景色匹配） */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 48px;
  height: 48px;
  background: #165dff;
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
  box-shadow: 0 2px 8px rgba(22, 93, 255, 0.3);
  cursor: pointer;
  z-index: 998;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
}
.back-to-top.show {
  opacity: 1;
  visibility: visible;
}
.back-to-top img {
  width: 32px;
  height: 32px;
}

/* 4. 主内容区通用样式（新增：背景色统一） */
.main {
  margin-top: 80px;
  padding-bottom: 4rem;
}

/* 5. 页脚样式（新增：背景色与浅蓝色协调） */
.footer {
  background: #fff; /* 页脚保持白色，提升视觉层次 */
  color: #333;
  padding: 3rem 0 1rem;
}
.footer .container {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  margin-bottom: 2rem;
}
.footer-col h3 {
  color: #165dff;
  font-size: 1.2rem;
  border-left: 4px solid #165dff;
  padding-left: 0.8rem;
  margin-bottom: 1rem;
}
.footer-col a {
  color: #333;
  display: block;
  margin-bottom: 0.5rem;
}
.footer-col a:hover {
  color: #165dff;
  padding-left: 0.5rem;
}
.footer-copyright {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid #e6f7ff; /* 页脚顶部边框与背景色呼应 */
  font-size: 0.9rem;
}
.footer-copyright a {
  color: #165dff;
}

/* 6. 新闻列表通用样式（新增：背景色统一） */
.news-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}
.news-item {
  border-radius: 8px;
  box-shadow: 0 2px 12px rgba(0,0,0,0.08);
  overflow: hidden;
  transition: all 0.3s ease;
  background: #fff; /* 新闻卡片保持白色，突出内容 */
}
.news-item:hover {
  box-shadow: 0 4px 20px rgba(0,0,0,0.12);
  transform: translateY(-5px);
}
.news-item-img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}
.news-item-content {
  padding: 1rem;
}
.news-item-title {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}
.news-item-desc {
  font-size: 0.9rem;
  color: #666;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: 1rem;
}
.news-item-time {
  font-size: 0.8rem;
  color: #999;
}

/* 7. 响应式布局（新增：适配浅蓝色背景） */
@media (max-width: 768px) {
  h1 {
    font-size: 1.8rem;
  }
  h2 {
    font-size: 1.6rem;
  }
  .footer .container {
    grid-template-columns: repeat(2, 1fr);
  }
  .news-list {
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  }
}
@media (max-width: 375px) {
  h1 {
    font-size: 1.5rem;
  }
  h2 {
    font-size: 1.3rem;
  }
  .nav-list {
    position: fixed;
    top: 0;
    right: -100%;
    width: 80%;
    height: 100vh;
    background: #fff;
    flex-direction: column;
    padding: 5rem 2rem;
    gap: 1.5rem;
    box-shadow: -2px 0 10px rgba(0,0,0,0.1);
    z-index: 9999;
    transition: all 0.3s ease;
  }
  .nav-list.show {
    right: 0;
  }
  .menu-btn, .close-btn {
    display: block;
    position: relative;
    z-index: 99999;
  }
  .close-btn {
    position: absolute;
    top: 1rem;
    right: 1rem;
  }
  .footer .container {
    grid-template-columns: 1fr;
  }
  .news-list {
    grid-template-columns: 1fr;
  }
  .back-to-top {
    width: 40px;
    height: 40px;
    bottom: 1rem;
    right: 1rem;
  }
  .btn {
    padding: 0.6rem 1.5rem;
    font-size: 0.9rem;
  }
}

/* 8. 页面专属样式（按需扩展，保持代码整洁） */
/* 主页横幅 - 文字左/图片右 固定布局，响应式适配 */
.banner {
  width: 100%;
  height: calc(100vh - 80px); /* 保持原横幅高度，不改变页面结构 */
  background: url("../images/banner-main.png") no-repeat center center;
  background-size: cover;
  display: flex;
  align-items: center;
  justify-content: flex-start; /* 保持原横幅左对齐的整体视觉 */
  color: #fff;
  padding: 0 1rem;
  margin-bottom: 3rem;
  overflow: hidden; /* 防止图片溢出 */
}
/* 横幅包裹层 - 核心：固定左右排列，限制最大宽度 */
.banner-wrap {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between; /* 强制左右两端分布，图片靠右 */
  gap: 4rem; /* 文字和图片间距，更宽松不拥挤 */
  flex-wrap: wrap; /* 仅手机端换行，平板/电脑始终分栏 */
}
/* 左侧文字区 - 占比稍大，突出核心内容 */
.banner-content {
  flex: 1 1 50%; /* 文字区占50% */
  min-width: 320px; /* 最小宽度，防止挤压 */
  z-index: 2; /* 文字层级高于图片，不被遮挡 */
}
.banner-content h1 {
  color: #000;
  font-size: 2.5rem;
  margin-bottom: 1rem;
  line-height: 1.4;
}
.banner-content p {
  font-size: 1.2rem;
  margin-bottom: 2rem;
  max-width: 600px;
  line-height: 1.7;
}
.banner-content .btn {
  font-size: 1.1rem;
  padding: 1rem 2.5rem;
}
/* 右侧图片区 - 固定占比，图片自适应 */
.banner-img {
  flex: 1 1 40%; /* 图片区占40%，略窄于文字区，视觉平衡 */
  min-width: 320px; /* 最小宽度，保证图片展示效果 */
  display: flex;
  align-items: center;
  justify-content: flex-end; /* 图片在自身区域内再靠右，双重保证右侧定位 */
}
/* 展示图样式 - 高清适配，加轻微效果突出 */
.banner-img img {
  width: 100%;
  height: auto;
  max-height: 600px; /* 限制图片最大高度，适配横幅区域 */
  object-fit: contain; /* 保持图片比例，不拉伸变形 */
  border-radius: 8px;
  box-shadow: 0 6px 25px rgba(0, 0, 0, 0.3); /* 加深阴影，和背景区分更明显 */
}
/* 下载板块 */
.download-section {
  text-align: center;
  padding: 3rem 0;
}
.download-btn {
  margin-top: 2rem;
}
/* 其他原有页面专属样式（教程/新闻/关于）保留不变 */
.tutorial-section {
  padding: 3rem 0;
}
.tutorial-content {
  margin-top: 2rem;
  line-height: 1.8;
}
.tutorial-content img {
  margin: 1rem auto;
  border-radius: 8px;
}
.about-section {
  padding: 3rem 0;
}
.about-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}
.about-item {
  text-align: center;
  padding: 1rem;
  background: #000;
}
.about-item img {
  width: 64px;
  height: 64px;
  margin: 0 auto 1rem;
}