/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: #1A1A2E; background: #fff; line-height: 1.6;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul, ol { list-style: none; }

/* ===== Utility ===== */
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.section { padding: 80px 0; }
.section-title { text-align: center; font-size: 2rem; font-weight: 700; margin-bottom: 16px; color: #1A1A2E; }
.section-desc { text-align: center; font-size: 1.1rem; color: #555; max-width: 680px; margin: 0 auto 48px; }
.btn {
  display: inline-block; padding: 14px 36px; border-radius: 10px; font-size: 1rem; font-weight: 600;
  transition: background .25s, transform .15s; cursor: pointer; text-align: center;
}
.btn-primary { background: linear-gradient(135deg, #2563EB, #3B82F6); color: #fff; }
.btn-primary:hover { background: linear-gradient(135deg, #1D4ED8, #2563EB); transform: translateY(-1px); }
.btn-outline { border: 2px solid #2563EB; color: #2563EB; background: transparent; }
.btn-outline:hover { background: #2563EB; color: #fff; }
.btn-sm { padding: 10px 24px; font-size: .9rem; }

/* ===== Header ===== */
.site-header {
  position: sticky; top: 0; z-index: 1000; background: rgba(255,255,255,.96);
  backdrop-filter: blur(10px); border-bottom: 1px solid #eee;
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  max-width: 1200px; margin: 0 auto; padding: 0 20px; height: 68px;
}
.logo { display: flex; align-items: center; gap: 10px; font-size: 1.4rem; font-weight: 700; color: #2563EB; }
.logo-icon { width: 36px; height: 36px; background: linear-gradient(135deg, #2563EB, #3B82F6); border-radius: 8px; display: flex; align-items: center; justify-content: center; color: #fff; font-weight: 800; font-size: 1.1rem; }
.nav-menu { display: flex; align-items: center; gap: 32px; }
.nav-menu a { font-size: .95rem; color: #333; font-weight: 500; transition: color .2s; }
.nav-menu a:hover, .nav-menu a.active { color: #2563EB; }
.header-cta { display: flex; gap: 12px; align-items: center; }
.hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 8px; }
.hamburger span { width: 24px; height: 2px; background: #333; border-radius: 2px; }

/* ===== Hero ===== */
.hero {
  background: linear-gradient(160deg, #EFF6FF 0%, #DBEAFE 50%, #BFDBFE 100%);
  padding: 100px 0 80px; text-align: center;
}
.hero-title { font-size: 2.8rem; font-weight: 800; margin-bottom: 20px; color: #1A1A2E; line-height: 1.3; }
.hero-title span { color: #2563EB; }
.hero-subtitle { font-size: 1.2rem; color: #444; max-width: 600px; margin: 0 auto 32px; }
.hero-tags { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; margin-bottom: 40px; }
.hero-tag {
  display: inline-flex; align-items: center; gap: 8px;
  background: #fff; padding: 10px 20px; border-radius: 50px;
  font-size: .9rem; color: #333; box-shadow: 0 2px 8px rgba(0,0,0,.06);
}
.hero-actions { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; margin-bottom: 48px; }
.hero-trust { display: flex; justify-content: center; gap: 32px; flex-wrap: wrap; opacity: .7; }
.trust-item { display: flex; align-items: center; gap: 8px; font-size: .85rem; color: #555; }
.trust-icon { width: 20px; height: 20px; background: #2563EB; border-radius: 50%; display: flex; align-items: center; justify-content: center; color: #fff; font-size: .7rem; }

/* ===== Features ===== */
.features { background: #fff; }
.features-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.feature-card {
  background: #F8FAFC; border: 1px solid #E2E8F0; border-radius: 16px;
  padding: 36px 28px; text-align: center; transition: transform .25s, box-shadow .25s;
}
.feature-card:hover { transform: translateY(-4px); box-shadow: 0 12px 32px rgba(37,99,235,.1); }
.feature-icon {
  width: 64px; height: 64px; margin: 0 auto 20px; border-radius: 16px;
  background: linear-gradient(135deg, #EFF6FF, #DBEAFE);
  display: flex; align-items: center; justify-content: center; font-size: 1.8rem;
}
.feature-card h3 { font-size: 1.15rem; font-weight: 600; margin-bottom: 12px; color: #1A1A2E; }
.feature-card p { font-size: .9rem; color: #666; line-height: 1.6; }

/* ===== Platform ===== */
.platforms { background: #F8FAFC; }
.platform-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.platform-card {
  background: #fff; border: 1px solid #E2E8F0; border-radius: 16px;
  padding: 36px 20px; text-align: center; transition: transform .25s, box-shadow .25s;
}
.platform-card:hover { transform: translateY(-4px); box-shadow: 0 8px 24px rgba(0,0,0,.08); }
.platform-icon { font-size: 3rem; margin-bottom: 16px; }
.platform-card h3 { font-size: 1.1rem; font-weight: 600; margin-bottom: 8px; }
.platform-card p { font-size: .85rem; color: #888; margin-bottom: 20px; }
.platform-note { text-align: center; margin-top: 32px; font-size: 1rem; color: #555; }

/* ===== Trust ===== */
.trust { background: #fff; }
.trust-stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; margin-bottom: 48px; }
.stat-card { text-align: center; padding: 32px 16px; background: #F8FAFC; border-radius: 16px; }
.stat-number { font-size: 2.4rem; font-weight: 800; color: #2563EB; margin-bottom: 8px; }
.stat-label { font-size: .9rem; color: #666; }
.trust-badges { display: flex; justify-content: center; gap: 40px; flex-wrap: wrap; margin-bottom: 48px; }
.badge-item { display: flex; flex-direction: column; align-items: center; gap: 8px; }
.badge-icon { width: 60px; height: 60px; background: linear-gradient(135deg, #EFF6FF, #DBEAFE); border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 1.5rem; }
.badge-text { font-size: .8rem; color: #666; text-align: center; }
.testimonials { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.testimonial-card {
  background: #F8FAFC; border-radius: 16px; padding: 28px; border: 1px solid #E2E8F0;
}
.testimonial-card p { font-size: .95rem; color: #444; line-height: 1.7; margin-bottom: 16px; font-style: italic; }
.testimonial-author { font-size: .85rem; color: #888; }

/* ===== Pricing ===== */
.pricing { background: #F8FAFC; }
.pricing-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; margin-bottom: 32px; }
.pricing-card {
  background: #fff; border: 2px solid #E2E8F0; border-radius: 16px;
  padding: 36px 24px; text-align: center; transition: transform .25s, border-color .25s;
}
.pricing-card:hover { transform: translateY(-4px); }
.pricing-card.popular { border-color: #2563EB; position: relative; }
.popular-badge {
  position: absolute; top: -14px; left: 50%; transform: translateX(-50%);
  background: #2563EB; color: #fff; padding: 4px 16px; border-radius: 20px; font-size: .8rem;
}
.pricing-card h3 { font-size: 1.2rem; font-weight: 600; margin-bottom: 8px; }
.pricing-price { font-size: 2rem; font-weight: 800; color: #2563EB; margin-bottom: 4px; }
.pricing-unit { font-size: .85rem; color: #888; margin-bottom: 20px; }
.pricing-features { margin-bottom: 24px; }
.pricing-features li { font-size: .9rem; color: #555; padding: 6px 0; }
.pricing-trial { text-align: center; margin-top: 16px; }
.pricing-trial a { color: #2563EB; font-weight: 600; }

/* ===== Footer ===== */
.site-footer { background: #1A1A2E; color: #ccc; padding: 60px 0 30px; }
.footer-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 32px; margin-bottom: 40px; }
.footer-col h4 { color: #fff; font-size: 1rem; margin-bottom: 16px; }
.footer-col a { display: block; font-size: .9rem; color: #999; padding: 4px 0; transition: color .2s; }
.footer-col a:hover { color: #3B82F6; }
.footer-bottom { border-top: 1px solid #333; padding-top: 24px; display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 16px; }
.footer-bottom p { font-size: .85rem; color: #777; }
.footer-lang { display: flex; gap: 16px; }
.footer-lang a { font-size: .85rem; color: #777; }
.footer-lang a:hover { color: #3B82F6; }

/* ===== Page Hero (inner pages) ===== */
.page-hero {
  background: linear-gradient(160deg, #EFF6FF, #DBEAFE);
  padding: 60px 0 50px; text-align: center;
}
.page-hero h1 { font-size: 2.2rem; font-weight: 700; margin-bottom: 12px; }
.page-hero p { font-size: 1.05rem; color: #555; max-width: 600px; margin: 0 auto; }
.breadcrumb { margin-top: 16px; font-size: .85rem; color: #888; }
.breadcrumb a { color: #2563EB; }

/* ===== Guide Steps ===== */
.guide-steps { max-width: 800px; margin: 0 auto; }
.guide-step {
  display: flex; gap: 24px; margin-bottom: 40px; padding: 28px;
  background: #F8FAFC; border-radius: 16px; border: 1px solid #E2E8F0;
}
.step-number {
  flex-shrink: 0; width: 48px; height: 48px; border-radius: 50%;
  background: linear-gradient(135deg, #2563EB, #3B82F6); color: #fff;
  display: flex; align-items: center; justify-content: center; font-size: 1.2rem; font-weight: 700;
}
.step-content h3 { font-size: 1.1rem; font-weight: 600; margin-bottom: 8px; }
.step-content p { font-size: .95rem; color: #555; line-height: 1.7; }

/* ===== Download ===== */
.download-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; max-width: 800px; margin: 0 auto; }
.download-card {
  background: #fff; border: 1px solid #E2E8F0; border-radius: 16px;
  padding: 32px; display: flex; align-items: center; gap: 20px;
  transition: transform .25s, box-shadow .25s;
}
.download-card:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,.08); }
.download-icon { font-size: 2.5rem; flex-shrink: 0; }
.download-info h3 { font-size: 1.1rem; font-weight: 600; margin-bottom: 4px; }
.download-info p { font-size: .85rem; color: #888; margin-bottom: 12px; }

/* ===== FAQ / Help ===== */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-category { margin-bottom: 48px; }
.faq-category h3 {
  font-size: 1.3rem; font-weight: 600; margin-bottom: 20px; color: #2563EB;
  padding-bottom: 12px; border-bottom: 2px solid #DBEAFE;
}
.faq-item {
  background: #F8FAFC; border: 1px solid #E2E8F0; border-radius: 12px;
  padding: 24px; margin-bottom: 16px;
}
.faq-item h4 { font-size: 1rem; font-weight: 600; margin-bottom: 12px; color: #1A1A2E; }
.faq-answer ol { padding-left: 20px; list-style: decimal; }
.faq-answer ol li { font-size: .9rem; color: #555; line-height: 1.7; padding: 4px 0; }
.faq-answer p { font-size: .9rem; color: #555; line-height: 1.7; }

/* ===== About / Privacy / Terms / Contact ===== */
.content-page { max-width: 800px; margin: 0 auto; }
.content-page h2 { font-size: 1.4rem; font-weight: 600; margin: 32px 0 16px; color: #1A1A2E; }
.content-page h3 { font-size: 1.15rem; font-weight: 600; margin: 24px 0 12px; color: #333; }
.content-page p { font-size: .95rem; color: #555; line-height: 1.8; margin-bottom: 16px; }
.content-page ul { padding-left: 20px; margin-bottom: 16px; }
.content-page ul li { font-size: .95rem; color: #555; line-height: 1.8; padding: 4px 0; list-style: disc; }

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .features-grid, .platform-grid, .pricing-grid, .trust-stats { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: repeat(3, 1fr); }
  .testimonials { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
  .nav-menu { display: none; }
  .hamburger { display: flex; }
  .header-cta .btn-outline { display: none; }
  .hero-title { font-size: 2rem; }
  .hero-subtitle { font-size: 1rem; }
  .features-grid, .platform-grid, .pricing-grid, .trust-stats, .download-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
  .section { padding: 48px 0; }
  .hero { padding: 60px 0 50px; }
  .guide-step { flex-direction: column; gap: 12px; }
  .footer-bottom { flex-direction: column; text-align: center; }
}