/* ===== 基础重置 ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body { font-family: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif; color: #1a1a2e; background: #fff; line-height: 1.6; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
img { max-width: 100%; }

/* ===== 容器 ===== */
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ===== 导航 ===== */
.header { position: fixed; top: 0; left: 0; right: 0; z-index: 1000; background: rgba(255,255,255,0.95); backdrop-filter: blur(12px); border-bottom: 1px solid #f0f0f0; transition: box-shadow .3s; }
.header.scrolled { box-shadow: 0 2px 20px rgba(0,0,0,.08); }
.header .container { display: flex; align-items: center; height: 64px; gap: 32px; }
.nav-brand { display: flex; align-items: center; gap: 10px; flex-shrink: 0; }
.logo-icon { width: 32px; height: 24px; }
.brand-name { font-size: 18px; font-weight: 700; color: #1a1a2e; }
.brand-name em { font-style: normal; color: #1677ff; }
.nav-links { display: flex; gap: 28px; margin-left: auto; }
.nav-links a { font-size: 15px; color: #555; font-weight: 500; transition: color .2s; }
.nav-links a:hover { color: #1677ff; }
.nav-btns { display: flex; gap: 10px; flex-shrink: 0; }
.btn-login { padding: 8px 20px; border: 1.5px solid #ddd; border-radius: 8px; font-size: 14px; font-weight: 600; color: #333; transition: all .2s; }
.btn-login:hover { border-color: #1677ff; color: #1677ff; }
.btn-register { padding: 8px 20px; background: #1677ff; border-radius: 8px; font-size: 14px; font-weight: 700; color: #fff; transition: all .2s; }
.btn-register:hover { background: #0958d9; transform: translateY(-1px); }
.menu-toggle { display: none; background: none; border: none; font-size: 22px; cursor: pointer; color: #333; }
.mobile-menu { display: none; flex-direction: column; padding: 12px 24px 16px; border-top: 1px solid #f0f0f0; background: #fff; }
.mobile-menu a { padding: 10px 0; font-size: 15px; color: #333; border-bottom: 1px solid #f5f5f5; }
.mobile-menu .mobile-register { margin-top: 12px; background: #1677ff; color: #fff; text-align: center; padding: 12px; border-radius: 8px; font-weight: 700; border: none; }
.mobile-menu.open { display: flex; }

/* ===== Hero ===== */
.hero { padding: 120px 0 80px; background: linear-gradient(135deg, #f0f7ff 0%, #e6f4ff 40%, #f0f9ff 100%); }
.hero-content { max-width: 680px; }
.hero-badge { display: inline-block; background: rgba(22,119,255,.1); color: #0050b3; border: 1px solid rgba(22,119,255,.25); border-radius: 20px; padding: 6px 16px; font-size: 13px; font-weight: 600; margin-bottom: 20px; }
.hero-title { font-size: clamp(32px, 5vw, 52px); font-weight: 800; line-height: 1.2; color: #1a1a2e; margin-bottom: 16px; }
.hero-title span { color: #1677ff; }
.hero-desc { font-size: 17px; color: #555; line-height: 1.8; margin-bottom: 32px; max-width: 560px; }
.hero-btns { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 40px; }
.btn-primary { display: inline-flex; align-items: center; gap: 8px; background: #1a1a2e; color: #fff; padding: 14px 28px; border-radius: 10px; font-size: 15px; font-weight: 700; transition: all .2s; }
.btn-primary:hover { background: #2d2d4e; transform: translateY(-2px); box-shadow: 0 8px 24px rgba(26,26,46,.2); }
.btn-secondary { display: inline-flex; align-items: center; gap: 8px; background: #1677ff; color: #fff; padding: 14px 28px; border-radius: 10px; font-size: 15px; font-weight: 700; transition: all .2s; }
.btn-secondary:hover { background: #0958d9; transform: translateY(-2px); box-shadow: 0 8px 24px rgba(22,119,255,.3); }
.btn-outline { display: inline-flex; align-items: center; gap: 8px; border: 2px solid #1677ff; color: #1677ff; padding: 12px 28px; border-radius: 10px; font-size: 15px; font-weight: 700; transition: all .2s; }
.btn-outline:hover { background: #1677ff; color: #fff; }
.hero-stats { display: flex; gap: 40px; flex-wrap: wrap; }
.stat { display: flex; flex-direction: column; }
.stat strong { font-size: 26px; font-weight: 800; color: #1a1a2e; }
.stat span { font-size: 13px; color: #888; margin-top: 2px; }

/* ===== 区块标题 ===== */
.section-header { text-align: center; margin-bottom: 56px; }
.section-header h2 { font-size: clamp(24px, 3.5vw, 36px); font-weight: 800; color: #1a1a2e; margin-bottom: 12px; }
.section-header p { font-size: 16px; color: #777; }
.section-header.light h2 { color: #fff; }
.section-header.light p { color: rgba(255,255,255,.75); }

/* ===== 功能区 ===== */
.features { padding: 80px 0; background: #fff; }
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.feature-card { background: #fafafa; border: 1px solid #f0f0f0; border-radius: 16px; padding: 32px 28px; transition: all .3s; }
.feature-card:hover { transform: translateY(-4px); box-shadow: 0 12px 40px rgba(22,119,255,.1); border-color: #1677ff; }
.feature-icon { font-size: 36px; margin-bottom: 16px; }
.feature-card h3 { font-size: 18px; font-weight: 700; color: #1a1a2e; margin-bottom: 10px; }
.feature-card p { font-size: 14px; color: #666; line-height: 1.7; }

/* ===== 下载区 ===== */
.download { padding: 80px 0; background: linear-gradient(135deg, #1a1a2e 0%, #0d2147 100%); }
.download-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.download-card { background: rgba(255,255,255,.06); border: 1px solid rgba(255,255,255,.12); border-radius: 16px; padding: 32px 24px; text-align: center; color: #fff; position: relative; transition: all .3s; }
.download-card:hover { background: rgba(255,255,255,.1); transform: translateY(-4px); }
.download-card.featured { border-color: #1677ff; background: rgba(22,119,255,.1); }
.dl-badge { position: absolute; top: -12px; left: 50%; transform: translateX(-50%); background: #1677ff; color: #fff; font-size: 12px; font-weight: 700; padding: 4px 14px; border-radius: 20px; }
.dl-icon { width: 72px; height: 72px; background: rgba(255,255,255,.1); border-radius: 16px; display: flex; align-items: center; justify-content: center; margin: 0 auto 16px; }
.download-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 8px; }
.download-card p { font-size: 13px; color: rgba(255,255,255,.6); margin-bottom: 16px; line-height: 1.6; }
.download-card ul { text-align: left; margin-bottom: 24px; }
.download-card ul li { font-size: 13px; color: rgba(255,255,255,.8); padding: 4px 0; padding-left: 16px; position: relative; }
.download-card ul li::before { content: '✓'; position: absolute; left: 0; color: #1677ff; font-weight: 700; }
.dl-btn { display: block; background: #1677ff; color: #fff; padding: 12px; border-radius: 10px; font-size: 14px; font-weight: 700; transition: all .2s; }
.dl-btn:hover { background: #0958d9; transform: translateY(-1px); }

/* ===== 关于区 ===== */
.about { padding: 80px 0; background: #f8f9fa; }
.about-inner { display: grid; grid-template-columns: 1fr 280px; gap: 60px; align-items: start; }
.about-text h2 { font-size: clamp(24px, 3vw, 32px); font-weight: 800; color: #1a1a2e; margin-bottom: 20px; }
.about-text p { font-size: 15px; color: #555; line-height: 1.8; margin-bottom: 16px; }
.about-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 20px; }
.about-tags span { background: #fff; border: 1px solid #e8e8e8; color: #555; font-size: 13px; padding: 4px 12px; border-radius: 20px; }
.about-stats { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.about-stat { background: #fff; border-radius: 12px; padding: 20px; text-align: center; box-shadow: 0 2px 12px rgba(0,0,0,.06); }
.about-stat strong { display: block; font-size: 22px; font-weight: 800; color: #1677ff; margin-bottom: 4px; }
.about-stat span { font-size: 13px; color: #888; }

/* ===== FAQ ===== */
.faq { padding: 80px 0; background: #fff; }
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { border: 1px solid #f0f0f0; border-radius: 12px; margin-bottom: 12px; overflow: hidden; transition: all .2s; }
.faq-item:hover { border-color: #1677ff; }
.faq-q { padding: 20px 24px; font-size: 16px; font-weight: 600; color: #1a1a2e; cursor: pointer; display: flex; justify-content: space-between; align-items: center; }
.faq-q::after { content: '+'; font-size: 22px; color: #1677ff; font-weight: 300; transition: transform .3s; }
.faq-item.open .faq-q::after { transform: rotate(45deg); }
.faq-a { display: none; padding: 0 24px 20px; font-size: 14px; color: #666; line-height: 1.8; }
.faq-item.open .faq-a { display: block; }

/* ===== CTA ===== */
.cta { padding: 80px 0; background: linear-gradient(135deg, #1677ff 0%, #4096ff 100%); text-align: center; }
.cta h2 { font-size: clamp(24px, 3.5vw, 36px); font-weight: 800; color: #fff; margin-bottom: 12px; }
.cta p { font-size: 16px; color: rgba(255,255,255,.8); margin-bottom: 32px; }
.cta-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn-white { display: inline-flex; align-items: center; gap: 8px; background: rgba(255,255,255,.15); color: #fff; border: 2px solid rgba(255,255,255,.5); padding: 14px 32px; border-radius: 10px; font-size: 15px; font-weight: 700; transition: all .2s; }
.btn-white:hover { background: rgba(255,255,255,.25); transform: translateY(-2px); }
.cta .btn-primary { background: #fff; color: #1677ff; }
.cta .btn-primary:hover { background: #f0f7ff; transform: translateY(-2px); }

/* ===== 页脚 ===== */
.footer { background: #1a1a2e; padding: 60px 0 0; color: rgba(255,255,255,.7); }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer-brand p { font-size: 14px; line-height: 1.7; margin-top: 12px; color: rgba(255,255,255,.5); }
.footer-col h4 { font-size: 15px; font-weight: 700; color: #fff; margin-bottom: 16px; }
.footer-col a { display: block; font-size: 14px; color: rgba(255,255,255,.55); margin-bottom: 8px; transition: color .2s; }
.footer-col a:hover { color: #1677ff; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.08); padding: 20px 0; text-align: center; }
.footer-bottom p { font-size: 12px; color: rgba(255,255,255,.35); line-height: 1.8; }

/* ===== 底部悬浮栏 ===== */
.fixbar { position: fixed; bottom: 0; left: 0; right: 0; z-index: 999; background: rgba(26,26,46,.97); backdrop-filter: blur(10px); display: flex; align-items: center; justify-content: center; gap: 12px; padding: 12px 20px; border-top: 1px solid rgba(255,255,255,.1); }
.fix-btn { display: inline-flex; align-items: center; gap: 8px; padding: 10px 28px; border-radius: 8px; font-size: 14px; font-weight: 700; transition: all .2s; }
.fix-btn.apple { background: #fff; color: #1a1a2e; }
.fix-btn.apple:hover { background: #f0f0f0; }
.fix-btn.android { background: #1677ff; color: #fff; }
.fix-btn.android:hover { background: #0958d9; }
.fix-close { background: none; border: none; color: rgba(255,255,255,.5); font-size: 18px; cursor: pointer; padding: 8px; margin-left: 8px; transition: color .2s; }
.fix-close:hover { color: #fff; }
.fixbar.hidden { display: none; }

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .download-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .about-inner { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
  .nav-links, .nav-btns { display: none; }
  .menu-toggle { display: block; margin-left: auto; }
  .features-grid { grid-template-columns: 1fr; }
  .download-grid { grid-template-columns: 1fr; }
  .hero-btns { flex-direction: column; align-items: flex-start; }
  .hero-stats { gap: 24px; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 24px; }
  .footer-brand { grid-column: 1 / -1; }
}
@media (max-width: 480px) {
  .footer-grid { grid-template-columns: 1fr; }
  .hero-stats { gap: 16px; }
  .stat strong { font-size: 22px; }
}