* { margin: 0; padding: 0; box-sizing: border-box; }
:root { --primary-color: #2563eb; --primary-dark: #1d4ed8; --secondary-color: #10b981; --dark-color: #1f2937; --light-color: #f9fafb; --gray-color: #6b7280; --border-color: #e5e7eb; --success-color: #10b981; --danger-color: #ef4444; --warning-color: #f59e0b; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif; line-height: 1.6; color: var(--dark-color); background-color: var(--light-color); }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
header { background: #fff; box-shadow: 0 2px 10px rgba(0,0,0,0.1); position: sticky; top: 0; z-index: 1000; }
.header-top { background: var(--dark-color); color: #fff; padding: 8px 0; font-size: 14px; }
.header-top .container { display: flex; justify-content: space-between; align-items: center; }
.header-top a { color: #fff; text-decoration: none; margin-left: 20px; }
.navbar { display: flex; justify-content: space-between; align-items: center; padding: 15px 20px; max-width: 1200px; margin: 0 auto; }
.logo { font-size: 24px; font-weight: bold; color: var(--primary-color); text-decoration: none; display: flex; align-items: center; gap: 10px; }
.nav-links { display: flex; gap: 30px; align-items: center; }
.nav-links > a { color: var(--dark-color); text-decoration: none; font-weight: 500; position: relative; padding: 10px 0; transition: color 0.3s; }
.nav-links > a:hover, .nav-links > a.active { color: var(--primary-color); }
.nav-links > a::after { content: ''; position: absolute; bottom: 0; left: 0; width: 0; height: 2px; background: var(--primary-color); transition: width 0.3s; }
.nav-links > a:hover::after, .nav-links > a.active::after { width: 100%; }
.btn-cta { background: linear-gradient(135deg, var(--primary-color), var(--primary-dark)); color: #fff; padding: 12px 30px; border-radius: 25px; text-decoration: none; font-weight: 600; transition: all 0.3s; display: inline-block; }
.btn-cta:hover { transform: translateY(-2px); box-shadow: 0 5px 20px rgba(37,99,235,0.4); }
.btn-secondary { background: var(--secondary-color); color: #fff; padding: 10px 25px; border-radius: 20px; text-decoration: none; font-weight: 500; transition: all 0.3s; display: inline-block; }
.btn-secondary:hover { background: #059669; }
.mobile-menu-btn { display: none; background: none; border: none; font-size: 24px; cursor: pointer; color: var(--dark-color); }
.hero { background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); color: #fff; padding: 100px 0; text-align: center; position: relative; overflow: hidden; }
.hero h1 { font-size: 48px; font-weight: 800; margin-bottom: 20px; position: relative; z-index: 1; }
.hero p { font-size: 20px; margin-bottom: 30px; opacity: 0.9; position: relative; z-index: 1; }
.hero-buttons { position: relative; z-index: 1; display: flex; gap: 20px; justify-content: center; flex-wrap: wrap; }
.hero-stats { margin-top: 50px; display: flex; justify-content: center; gap: 50px; flex-wrap: wrap; position: relative; z-index: 1; }
.stat-item { text-align: center; }
.stat-item .number { font-size: 36px; font-weight: bold; display: block; }
.stat-item .label { font-size: 14px; opacity: 0.8; }
section { padding: 80px 0; }
.section-title { text-align: center; margin-bottom: 60px; }
.section-title h2 { font-size: 36px; font-weight: 700; color: var(--dark-color); margin-bottom: 15px; }
.section-title p { font-size: 16px; color: var(--gray-color); max-width: 600px; margin: 0 auto; }
.features-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(350px, 1fr)); gap: 30px; }
.feature-card { background: #fff; padding: 40px; border-radius: 15px; box-shadow: 0 5px 20px rgba(0,0,0,0.08); transition: all 0.3s; }
.feature-card:hover { transform: translateY(-10px); box-shadow: 0 15px 40px rgba(0,0,0,0.15); }
.feature-icon { width: 60px; height: 60px; background: linear-gradient(135deg, var(--primary-color), var(--primary-dark)); border-radius: 12px; display: flex; align-items: center; justify-content: center; font-size: 28px; color: #fff; margin-bottom: 20px; }
.feature-card h3 { font-size: 20px; font-weight: 600; margin-bottom: 15px; color: var(--dark-color); }
.feature-card p { color: var(--gray-color); line-height: 1.8; }
.platforms-section { background: linear-gradient(135deg, #f5f7fa 0%, #e4e8ec 100%); }
.platforms-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 30px; }
.platform-card { background: #fff; padding: 30px; border-radius: 10px; text-align: center; box-shadow: 0 5px 15px rgba(0,0,0,0.08); transition: all 0.3s; }
.platform-card:hover { transform: scale(1.05); }
.platform-icon { width: 80px; height: 80px; background: var(--light-color); border-radius: 50%; margin: 0 auto 15px; display: flex; align-items: center; justify-content: center; font-size: 32px; font-weight: bold; color: var(--primary-color); }
.comparison-section { background: #fff; }
.comparison-table { width: 100%; border-collapse: collapse; background: #fff; border-radius: 10px; overflow: hidden; box-shadow: 0 5px 20px rgba(0,0,0,0.08); }
.comparison-table th, .comparison-table td { padding: 20px; text-align: center; border-bottom: 1px solid var(--border-color); }
.comparison-table th { background: linear-gradient(135deg, var(--primary-color), var(--primary-dark)); color: #fff; font-weight: 600; }
.comparison-table th:first-child { background: var(--dark-color); }
.comparison-table tr:hover { background: var(--light-color); }
.comparison-table .check { color: var(--success-color); font-size: 24px; }
.comparison-table .cross { color: var(--danger-color); font-size: 24px; }
.contact-section { background: #fff; }
.contact-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 50px; }
.contact-form { background: var(--light-color); padding: 40px; border-radius: 15px; }
.form-group { margin-bottom: 20px; }
.form-group label { display: block; margin-bottom: 8px; font-weight: 500; color: var(--dark-color); }
.form-control { width: 100%; padding: 12px 15px; border: 1px solid var(--border-color); border-radius: 8px; font-size: 14px; transition: border-color 0.3s; }
.form-control:focus { outline: none; border-color: var(--primary-color); }
textarea.form-control { min-height: 120px; resize: vertical; }
.contact-info { padding: 20px 0; }
.contact-item { display: flex; align-items: center; gap: 15px; margin-bottom: 30px; }
.contact-icon { width: 50px; height: 50px; background: linear-gradient(135deg, var(--primary-color), var(--primary-dark)); border-radius: 50%; display: flex; align-items: center; justify-content: center; color: #fff; font-size: 20px; }
.contact-item h4 { font-size: 16px; font-weight: 600; margin-bottom: 5px; color: var(--dark-color); }
.contact-item p { color: var(--gray-color); }
footer { background: var(--dark-color); color: #fff; padding: 60px 0 20px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer-brand h3 { font-size: 24px; margin-bottom: 20px; color: var(--primary-color); }
.footer-brand p { color: rgba(255,255,255,0.7); line-height: 1.8; }
.footer-links h4 { font-size: 18px; margin-bottom: 20px; }
.footer-links ul { list-style: none; }
.footer-links li { margin-bottom: 10px; }
.footer-links a { color: rgba(255,255,255,0.7); text-decoration: none; transition: color 0.3s; }
.footer-links a:hover { color: var(--primary-color); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); padding-top: 20px; text-align: center; color: rgba(255,255,255,0.6); font-size: 14px; }
.footer-bottom a { color: rgba(255,255,255,0.6); text-decoration: none; }
.articles-section { background: var(--light-color); }
.articles-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 30px; }
.article-card { background: #fff; border-radius: 10px; overflow: hidden; box-shadow: 0 5px 15px rgba(0,0,0,0.08); transition: all 0.3s; }
.article-card:hover { transform: translateY(-5px); box-shadow: 0 15px 30px rgba(0,0,0,0.15); }
.article-image { height: 200px; background: linear-gradient(135deg, var(--primary-color), var(--primary-dark)); display: flex; align-items: center; justify-content: center; color: #fff; font-size: 48px; font-weight: bold; }
.article-content { padding: 25px; }
.article-card h3 { font-size: 18px; font-weight: 600; margin-bottom: 10px; color: var(--dark-color); }
.article-card .excerpt { color: var(--gray-color); font-size: 14px; margin-bottom: 15px; display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
.article-meta { display: flex; justify-content: space-between; align-items: center; font-size: 12px; color: var(--gray-color); }
.article-tags { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 15px; }
.tag { background: var(--light-color); padding: 4px 12px; border-radius: 15px; font-size: 12px; color: var(--gray-color); }
.article-top { position: relative; }
.article-top::before { content: '置顶'; position: absolute; top: 10px; right: 10px; background: var(--warning-color); color: #fff; padding: 4px 10px; border-radius: 4px; font-size: 12px; font-weight: 600; }
.pagination { display: flex; justify-content: center; gap: 10px; margin-top: 40px; }
.pagination a { padding: 10px 15px; background: #fff; border-radius: 8px; text-decoration: none; color: var(--dark-color); border: 1px solid var(--border-color); transition: all 0.3s; }
.pagination a:hover, .pagination a.active { background: var(--primary-color); color: #fff; border-color: var(--primary-color); }
.article-detail { max-width: 800px; margin: 0 auto; background: #fff; padding: 40px; border-radius: 15px; box-shadow: 0 5px 20px rgba(0,0,0,0.08); }
.article-detail h1 { font-size: 36px; font-weight: 700; margin-bottom: 20px; color: var(--dark-color); }
.article-detail .meta { display: flex; gap: 20px; margin-bottom: 30px; padding-bottom: 20px; border-bottom: 1px solid var(--border-color); color: var(--gray-color); font-size: 14px; }
.article-detail .content { font-size: 16px; line-height: 1.8; color: var(--dark-color); }
.article-detail .content p { margin-bottom: 20px; }
.article-detail .content h2 { font-size: 24px; margin: 30px 0 15px; color: var(--dark-color); }
.auth-container { max-width: 400px; margin: 80px auto; background: #fff; padding: 40px; border-radius: 15px; box-shadow: 0 5px 20px rgba(0,0,0,0.1); }
.auth-container h2 { text-align: center; margin-bottom: 30px; color: var(--dark-color); }
.auth-links { text-align: center; margin-top: 20px; }
.auth-links a { color: var(--primary-color); text-decoration: none; }
.btn-submit { width: 100%; padding: 12px; background: var(--primary-color); color: #fff; border: none; border-radius: 8px; font-size: 16px; font-weight: 600; cursor: pointer; transition: background 0.3s; }
.btn-submit:hover { background: var(--primary-dark); }
.alert { padding: 12px 20px; border-radius: 8px; margin-bottom: 20px; font-size: 14px; }
.alert-success { background: #d1fae5; color: #065f46; border: 1px solid #10b981; }
.alert-error { background: #fee2e2; color: #991b1b; border: 1px solid #ef4444; }
.user-center { max-width: 800px; margin: 40px auto; background: #fff; padding: 40px; border-radius: 15px; box-shadow: 0 5px 20px rgba(0,0,0,0.08); }
.user-center h1 { margin-bottom: 30px; color: var(--dark-color); }
.user-section { margin-bottom: 40px; }
.user-section h3 { margin-bottom: 20px; color: var(--dark-color); padding-bottom: 10px; border-bottom: 2px solid var(--primary-color); }
@media (max-width: 768px) {
  .mobile-menu-btn { display: block; }
  .nav-links { display: none; position: absolute; top: 100%; left: 0; right: 0; background: #fff; flex-direction: column; padding: 20px; box-shadow: 0 5px 10px rgba(0,0,0,0.1); }
  .nav-links.active { display: flex; }
  .hero h1 { font-size: 32px; }
  .hero p { font-size: 16px; }
  .hero-stats { flex-direction: column; gap: 30px; }
  .features-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .comparison-table { font-size: 12px; }
  .comparison-table th, .comparison-table td { padding: 10px; }
}
@media (max-width: 480px) {
  .hero { padding: 60px 0; }
  .hero h1 { font-size: 24px; }
  .hero-buttons { flex-direction: column; }
  .section-title h2 { font-size: 28px; }
  .container { padding: 0 15px; }
}