:root {
  --primary-color: #4a6bff;
  --secondary-color: #6c5ce7;
  --dark-color: #2d3436;
  --light-color: #f5f6fa;
  --success-color: #00b894;
  --border-radius: 8px;
  --box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
  --transition: all 0.3s ease;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}

body {
  background-color: #f9fafc;
  color: var(--dark-color);
  line-height: 1.6;
}

.container {
  max-width: 1600px;
  margin: 0 auto;
  padding: 0 30px;
}

/* 导航栏 */
header {
  background-color: white;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  position: fixed;
  width: 100%;
  z-index: 100;
}

nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 5px 0;
}

.nav_title {
  margin-left: 5px;
}

.logo {
  display: flex;
  align-items: center;
  font-size: 24px;
  font-weight: 700;
  color: var(--primary-color);
  text-decoration: none;
  transition: var(--transition);
}

.logo i {
  margin-right: 10px;
  color: var(--secondary-color);
}

.logo:hover {
  transform: translateY(-2px);
}

.nav-links {
  display: flex;
  list-style: none;
}

.nav-links li {
  margin-left: 30px;
}

.nav-links a {
  text-decoration: none;
  color: var(--dark-color);
  font-weight: 500;
  transition: var(--transition);
  position: relative;
  padding: 5px 0;
}

.nav-links a.active {
  color: #5171ff;
}

.nav-links a::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--primary-color);
  transition: var(--transition);
}

.nav-links a:hover::after {
  width: 100%;
}

.btn {
  display: inline-block;
  background-color: var(--primary-color);
  color: white;
  padding: 12px 24px;
  border-radius: var(--border-radius);
  text-decoration: none;
  font-weight: 500;
  transition: var(--transition);
  border: none;
  cursor: pointer;
}

.btn:hover {
  background-color: var(--secondary-color);
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

/* 移动端菜单按钮 */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--dark-color);
  font-size: 24px;
  cursor: pointer;
  padding: 10px;
}

/* 页脚 */
footer {
  background-color: var(--dark-color);
  color: white;
  padding: 60px 0 20px;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 40px;
  margin-bottom: 40px;
}

.footer-column {
  text-align: center;
}

.footer-column h3 {
  font-size: 18px;
  margin-bottom: 20px;
  position: relative;
  padding-bottom: 10px;
}

.footer-column h3::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 40px;
  height: 2px;
  background-color: var(--primary-color);
  transform: translateX(-50%);
}

.footer-column-info h3 {
  font-size: 18px;
  margin-bottom: 20px;
  position: relative;
  padding-bottom: 10px;
}

.footer-column-info h3::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 40px;
  height: 2px;
  background-color: var(--primary-color);
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  color: #b2bec3;
  text-decoration: none;
  transition: all 0.3s ease;
  position: relative;
  padding-left: 0;
}

.footer-links a:hover {
  color: white;
  padding-left: 5px;
}

.footer-links a::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 0;
  height: 1px;
  background-color: var(--primary-color);
  transition: width 0.3s ease;
}

.footer-links a:hover::before {
  width: 3px;
}

.copyright {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: #b2bec3;
  font-size: 14px;
}

/* 响应式设计补充 */
@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 70px;
    left: 0;
    width: 100%;
    background: white;
    flex-direction: column;
    align-items: center;
    padding: 20px 0;
    box-shadow: 0 10px 15px rgba(0, 0, 0, 0.1);
    transform: translateY(-150%);
    transition: transform 0.3s ease;
    z-index: 999;
  }

  .menu-toggle {
    display: block;
  }

  .nav-links.active {
    transform: translateY(0);
  }

  .nav-links li {
    margin: 10px 0;
  }

  .nav-links a {
    display: block;
    padding: 10px 0;
  }

  .footer-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .footer-column h3::after {
    left: 50%;
    transform: translateX(-50%);
  }
  .footer-column-info h3::after {
    left: 50%;
    transform: translateX(-50%);
  }
}