/* 全局重置 + 必应SEO基础优化 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Microsoft YaHei", Arial, sans-serif;
}
html {
  scroll-behavior: smooth; /* 锚点平滑跳转 */
  font-size: 16px;
}
body {
  line-height: 1.6;
  color: #333;
  background-color: #f8f9fa;
}
/* 必应SEO：语义化标签基础样式 */
h1 {
  font-size: 2.5rem;
  color: #202124;
  margin-bottom: 20px;
}
h2 {
  font-size: 2rem;
  color: #202124;
  margin: 40px 0 20px;
  text-align: center;
}
h3 {
  font-size: 1.4rem;
  color: #4285F4;
  margin: 15px 0;
}
p {
  font-size: 1rem;
  color: #5f6368;
  margin-bottom: 15px;
}
a {
  text-decoration: none;
  color: inherit;
}
ul {
  list-style: none;
}
.container {
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 15px;
}

/* ===================== 长条固定导航栏 ===================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 70px;
  background: #fff;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  z-index: 999;
  display: flex;
  align-items: center;
  transition: all 0.3s ease;
}
.navbar.scroll {
  background: #4285F4;
  color: #fff;
}
.nav-wrapper {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}
.logo img {
  height: 40px;
  width: auto;
}
.logo-text {
  font-size: 1.2rem;
  font-weight: bold;
}
.nav-menu {
  display: flex;
  gap: 30px;
}
.nav-menu li a {
  font-size: 1rem;
  font-weight: 500;
  padding: 8px 12px;
  border-radius: 4px;
  transition: 0.3s;
}
.nav-menu li a:hover, .nav-menu li a.active {
  background: rgba(66,133,244,0.1);
  color: #4285F4;
}
.navbar.scroll .nav-menu li a:hover {
  background: rgba(255,255,255,0.2);
  color: #fff;
}

/* ===================== 主体内容间距（适配导航栏） ===================== */
.main {
  padding-top: 90px;
  padding-bottom: 60px;
}
/* 锚点目标区域 */
.section {
  padding: 60px 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
}

/* ===================== 卡片/图片通用样式 ===================== */
.img-box {
  width: 100%;
  border-radius: 12px;
  overflow: hidden;
  margin: 20px 0;
  box-shadow: 0 4px 15px rgba(0,0,0,0.05);
}
.img-box img {
  width: 100%;
  height: auto;
  display: block;
}
.card-group {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  margin: 40px 0;
}
.card {
  background: #fff;
  padding: 25px;
  border-radius: 12px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.05);
  transition: 0.3s;
}
.card:hover {
  transform: translateY(-5px);
}
.btn {
  display: inline-block;
  padding: 12px 30px;
  background: #4285F4;
  color: #fff;
  border-radius: 6px;
  font-weight: bold;
  transition: 0.3s;
  border: none;
  cursor: pointer;
  margin: 10px 0;
}
.btn:hover {
  background: #3367D6;
  transform: scale(1.05);
}

/* ===================== FAQ折叠样式 ===================== */
.faq-item {
  background: #fff;
  margin: 15px 0;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.faq-question {
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  font-weight: bold;
}
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
  margin-top: 10px;
}
.faq-answer.show {
  max-height: 200px;
}

/* ===================== 底部 ===================== */
.footer {
  background: #202124;
  color: #fff;
  padding: 40px 0;
  text-align: center;
}
.footer p {
  color: #ccc;
}

/* ===================== 响应式 ===================== */
@media (max-width: 768px) {
  .nav-menu {
    gap: 15px;
  }
  h1 {
    font-size: 2rem;
  }
  .section {
    padding: 40px 0;
  }
}