/* 通用样式 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB',
    'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
  line-height: 1.6;
  color: #1e293b;
  background: #f8fafc;
}

/* 导航栏 */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid #e2e8f0;
  z-index: 1000;
}

.navbar-content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  text-decoration: none;
  transition: transform 0.2s;
}

.logo:hover {
  transform: scale(1.02);
}

.logo svg {
  width: 32px;
  height: 32px;
}

.logo-text {
  font-size: 1.25rem;
  font-weight: 800;
  color: #1e293b;
}

.nav-links {
  display: flex;
  gap: 2rem;
  align-items: center;
}

.nav-links a:not(.btn-download-nav) {
  color: #64748b;
  text-decoration: none;
  transition: all 0.2s;
  font-weight: 500;
  font-size: 0.9375rem;
  position: relative;
}

@media (max-width: 768px) {
  .nav-links a:not(.btn-download-nav) {
    display: block;
  }
}

@media (max-width: 480px) {
  .nav-links a:not(.btn-download-nav) {
    display: none;
  }
}

.nav-links a:not(.btn-download-nav):hover {
  color: #2563eb;
}

.nav-links a:not(.btn-download-nav)::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: #2563eb;
  transition: width 0.2s;
}

.nav-links a:not(.btn-download-nav):hover::after {
  width: 100%;
}

.btn-download-nav {
  background: #2563eb;
  color: white;
  padding: 0.625rem 1.5rem;
  border-radius: 0.5rem;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9375rem;
  transition: all 0.2s;
}

.btn-download-nav:hover {
  background: #1d4ed8;
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
}

/* 容器 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* 通用Section */
section {
  padding: 5rem 0;
}

section h2 {
  font-size: 2.25rem;
  font-weight: 800;
  text-align: center;
  margin-bottom: 0.75rem;
  color: #1e293b;
}

section .subtitle {
  text-align: center;
  font-size: 1.0625rem;
  color: #64748b;
  margin-bottom: 3rem;
}

/* 页脚 */
.footer {
  background: #1e293b;
  color: #94a3b8;
  padding: 4rem 0 2rem;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  padding: 0 1.5rem;
  margin-bottom: 2rem;
}

.footer h3 {
  color: #ffffff;
  font-weight: 700;
  margin-bottom: 1rem;
  font-size: 1rem;
}

.footer ul {
  list-style: none;
}

.footer li {
  padding: 0.5rem 0;
}

.footer a {
  color: #94a3b8;
  text-decoration: none;
  transition: color 0.2s;
}

.footer a:hover {
  color: white;
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid #334155;
}

/* 滚动条 */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: #f1f5f9;
}

::-webkit-scrollbar-thumb {
  background: #cbd5e1;
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: #94a3b8;
}

/* 选择文本 */
::selection {
  background: #dbeafe;
  color: #1e293b;
}

/* 响应式 */
@media (max-width: 768px) {
  .navbar-content {
    padding: 0 1rem;
  }

  .nav-links {
    gap: 1.5rem;
  }

  .container {
    padding: 0 1rem;
  }

  section {
    padding: 4rem 0;
  }

  .footer-content {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
  }
}

@media (max-width: 480px) {
  .navbar-content {
    flex-wrap: wrap;
    height: auto;
    padding: 0.75rem 1rem;
  }

  .nav-links {
    width: 100%;
    justify-content: flex-end;
    gap: 1rem;
  }

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