/* css/style.css */
:root {
  --primary-color: #2563eb;
  --secondary-color: #1e40af;
  --text-main: #334155;
  --text-light: #64748b;
  --bg-main: #ffffff;
  --bg-light: #f8fafc;
  --border-color: #e2e8f0;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  color: var(--text-main);
  background-color: var(--bg-main);
  line-height: 1.6;
}
a { text-decoration: none; color: var(--primary-color); }
a:hover { color: var(--secondary-color); }

/* Language toggle visibility */
html:not([lang="zh"]) [data-lang="zh"] { display: none !important; }
html[lang="zh"] [data-lang="en"] { display: none !important; }

/* Navigation */
header {
  background-color: var(--bg-main);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 1000;
}
.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.logo { font-size: 1.5rem; font-weight: 700; color: var(--primary-color); }
.nav-links { display: flex; gap: 2rem; align-items: center; }
.nav-links a { color: var(--text-main); font-weight: 500; }
.nav-links a:hover { color: var(--primary-color); }
.lang-switch {
  background: var(--bg-light);
  border: 1px solid var(--border-color);
  padding: 0.5rem 1rem;
  border-radius: 4px;
  cursor: pointer;
  font-family: inherit;
}
.lang-switch:hover {
  background: var(--border-color);
}

/* Hero Section */
.hero {
  background-color: var(--bg-light);
  padding: 6rem 2rem;
  text-align: center;
}
.hero h1 { font-size: 3rem; margin-bottom: 1.5rem; color: #0f172a; }
.hero p { font-size: 1.25rem; color: var(--text-light); max-width: 800px; margin: 0 auto 2rem; }
.btn {
  display: inline-block;
  background-color: var(--primary-color);
  color: white;
  padding: 0.75rem 1.5rem;
  border-radius: 4px;
  font-weight: 600;
  border: none;
  cursor: pointer;
}
.btn:hover { background-color: var(--secondary-color); color: white; }

/* Sections */
.section { padding: 5rem 2rem; max-width: 1200px; margin: 0 auto; }
.section-title { text-align: center; font-size: 2.5rem; margin-bottom: 3rem; color: #0f172a; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 2rem; }
.card {
  background: var(--bg-main);
  border: 1px solid var(--border-color);
  padding: 2rem;
  border-radius: 8px;
  text-align: center;
  transition: transform 0.2s, box-shadow 0.2s;
}
.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1);
}
.card h3 { margin-bottom: 1rem; font-size: 1.25rem; color: #0f172a; }

/* Footer */
footer {
  background-color: #0f172a;
  color: #94a3b8;
  padding: 4rem 2rem 2rem;
}
.footer-grid {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 3rem;
  margin-bottom: 3rem;
}
.footer-col h4 { color: white; margin-bottom: 1.5rem; font-size: 1.25rem; }
.footer-col p { margin-bottom: 0.5rem; }
.footer-col a { color: #94a3b8; display: block; margin-bottom: 0.5rem; }
.footer-col a:hover { color: white; }
.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid #1e293b;
  max-width: 1200px;
  margin: 0 auto;
}

/* Legal Pages */
.legal-content { max-width: 800px; margin: 0 auto; padding: 4rem 2rem; }
.legal-content h1 { font-size: 2.5rem; margin-bottom: 2rem; color: #0f172a; }
.legal-content h2 { font-size: 1.5rem; margin: 2rem 0 1rem; color: #0f172a; }
.legal-content p { margin-bottom: 1rem; color: var(--text-main); }
.legal-content ul { margin-left: 2rem; margin-bottom: 1rem; }
.legal-content li { margin-bottom: 0.5rem; }

/* Responsive */
@media (max-width: 768px) {
  .nav-links { display: none; } /* Simplified for mobile, ideally needs a hamburger menu */
  .hero h1 { font-size: 2rem; }
  .section { padding: 3rem 2rem; }
}