/* 纯 CSS（无框架）- 简洁可维护 */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;600;700;800&display=swap');
:root{
  --primary:#dc143c;
  --accent:#fff5f6;
  --text:#081828;
  --muted:#6b7280;
  --container-max:1200px;
}
html{scroll-behavior:smooth}
*{box-sizing:border-box}

/* Focus (keyboard) accessibility */
:where(a,button){outline:none}
:where(a:focus-visible,button:focus-visible){box-shadow:0 0 0 4px rgba(220,20,60,0.12);border-radius:6px}
body{font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,"Helvetica Neue",Arial;line-height:1.6;color:var(--text);margin:0;background:linear-gradient(180deg,#fff,#fff)}
.container{max-width:var(--container-max);margin:0 auto;padding:0 18px}

/* Buttons and interactive transitions */
.btn{transition:transform .14s ease,box-shadow .14s ease,opacity .12s ease}
.btn:active{transform:translateY(1px);opacity:.98}
.nav-menu .btn:hover{transform:translateY(-2px)}

/* Testimonial fade and FAQ animation */
.testi{opacity:0;transform:translateY(6px);transition:opacity .4s ease,transform .4s ease}
.testi.active{opacity:1;transform:none}
.faq .a{max-height:0;overflow:hidden;transition:max-height .26s ease,padding .2s ease}
.faq .a.open{max-height:360px;padding:12px} 
.header{position:fixed;left:0;top:0;right:0;background:transparent;transition:background .25s,box-shadow .25s,padding .2s;z-index:60}
.header.sticky{background:#fff;box-shadow:0 6px 18px rgba(0,0,0,.06);border-bottom:1px solid rgba(0,0,0,.04);padding:10px 0}
.nav-row{display:flex;align-items:center;justify-content:space-between;padding:18px 0}
.brand img{height:44px}
.nav-menu ul{list-style:none;display:flex;gap:26px;align-items:center;margin:0;padding:0}
.nav-menu a{color:var(--text);text-decoration:none;padding:8px 0;font-weight:600}
.nav-menu a:hover{color:var(--primary)}
.nav-menu a.active{color:var(--primary)}
.nav-menu .btn{background:var(--primary);color:#fff;padding:10px 14px;border-radius:10px;box-shadow:0 6px 20px rgba(220,20,60,.12);font-weight:700}
.nav-menu .btn.outline{background:transparent;border:1px solid var(--primary);color:var(--primary)}
.mobile-toggle{display:none;background:none;border:0;padding:8px;cursor:pointer}
.mobile-toggle .bar{display:block;width:24px;height:2px;background:#111;margin:4px 0}

/* Hero */
.hero{padding:110px 0 70px;background:linear-gradient(180deg,#fff 0,#fff 100%)}
.hero-inner{display:grid;grid-template-columns:1fr 520px;gap:48px;align-items:center}
.hero-left h1{font-size:48px;margin-bottom:14px;font-weight:700;color:var(--text);line-height:1.02}
.hero-left p{color:var(--muted);margin-bottom:18px;font-size:16px}
.ctas{display:flex;gap:14px;align-items:center}
.cta-buttons{display:flex;gap:12px}
.cta-qr{margin-left:8px}
.qr-img{width:92px;height:92px;border-radius:8px;border:1px solid rgba(0,0,0,.06);box-shadow:0 8px 20px rgba(11,17,23,.06)}
.btn{display:inline-block;text-decoration:none;padding:10px 14px;border-radius:10px}
.btn.primary{background:var(--primary);color:#fff;box-shadow:0 8px 24px rgba(220,20,60,.12);font-weight:700}
.btn.outline{background:transparent;border:1px solid var(--primary);color:var(--primary)}
@media (max-width:700px){
  .cta-qr{display:none}
}
.hero-right img{max-width:100%;height:auto;border-radius:14px;box-shadow:0 20px 50px rgba(11,17,23,.06)}

.section-title{font-size:26px;margin:20px 0}
.features-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:20px}
.feature{background:#fff;padding:22px;border-radius:10px;text-align:center;box-shadow:0 10px 30px rgba(11,17,23,.04);transition:transform .18s ease}
.feature:hover{transform:translateY(-6px)}
.feature .icon{width:64px;height:64px;border-radius:50%;display:flex;align-items:center;justify-content:center;margin:0 auto 14px;background:var(--accent);font-size:26px;color:var(--primary)}
.feature h3{font-weight:700}

.screens-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
.screens-grid img{width:100%;border-radius:12px;border:1px solid rgba(0,0,0,.04);box-shadow:0 12px 30px rgba(11,17,23,.04)}

.kpis{display:flex;gap:18px;margin-top:16px}
.kpi{background:#fff;padding:10px 14px;border-radius:8px;box-shadow:0 6px 18px rgba(0,0,0,.03);text-align:center}
.kpi .num{font-weight:800;color:var(--primary);font-size:20px}
.kpi .label{font-size:13px;color:var(--muted)}

/* Section and layout refinements */
.hero{position:relative}
.hero::before{content:'';position:absolute;right:6%;top:10%;width:320px;height:320px;border-radius:50%;background:linear-gradient(180deg,rgba(220,20,60,.06),rgba(220,20,60,.02));z-index:0}
.hero-inner{position:relative;z-index:1}
section{padding:36px 0}
main{scroll-padding-top:72px}
.header .nav-row{padding:14px 0}
.brand img{height:36px}

.how .steps{display:flex;gap:12px;margin-top:14px}
.step{display:flex;gap:12px;align-items:flex-start;background:#fff;padding:12px;border-radius:8px;box-shadow:0 6px 18px rgba(0,0,0,.03)}
.step .num{width:36px;height:36px;border-radius:50%;background:var(--primary);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:700}
.step .desc .small{font-size:13px;color:var(--muted);margin-top:6px}

.testimonials{padding:40px 0;background:linear-gradient(180deg,rgba(220,20,60,0.03),rgba(255,255,255,0));}
.testimonials .container{position:relative}
/* 用户评价卡片网格（仿目标站样式） */
.testi-grid{display:grid;gap:18px;grid-template-columns:1fr}
.testimonial-card{background:#fff;padding:18px;border-radius:12px;border:1px solid rgba(11,17,23,.03);box-shadow:0 14px 36px rgba(11,17,23,.06);transition:transform .18s ease,box-shadow .18s ease;display:flex;flex-direction:column;gap:10px}
.testimonial-card:hover{transform:translateY(-6px);box-shadow:0 18px 44px rgba(11,17,23,.08)}
.testimonial-card .meta{display:flex;gap:12px;align-items:center}
.avatar{width:64px;height:64px;border-radius:50%;background:linear-gradient(180deg,#dc143c,#b40f2a);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:14px}
.meta-info{display:flex;flex-direction:column}
.meta-info .name{font-weight:700}
.stars{color:#f59e0b;margin-top:6px}
.quote{color:var(--text);font-size:15px;margin-top:6px}
.meta-foot{color:var(--muted);font-size:13px;margin-top:8px}
.more{margin-top:16px;text-align:center}
.more .btn{padding:10px 16px;border-radius:10px}

@media(min-width:700px){
  .testi-grid{grid-template-columns:repeat(2,1fr)}
}
@media(min-width:1200px){
  .testi-grid{grid-template-columns:repeat(2,1fr);gap:24px}
} 

.faq .accordion .item{margin-bottom:8px}
.faq .q{width:100%;text-align:left;padding:12px;border-radius:8px;background:#fff;border:1px solid #eee;cursor:pointer;display:flex;justify-content:space-between;align-items:center}
.faq .a{display:none;padding:12px;border-radius:8px;background:#fff;border:1px solid #eee;border-top:0}
.faq .a.open{display:block}

.faq{background:#fbfbfd;padding:36px 0;border-top:1px solid rgba(0,0,0,.02);border-bottom:1px solid rgba(0,0,0,.02)}
.download-cta{padding:26px 0;margin-top:16px;background:linear-gradient(180deg,#f8fafc,#fff);border-top:1px solid rgba(0,0,0,.02)}
.cta-inner img{max-width:240px}
.contact{background:#fffafb;padding:18px 0;border-top:1px solid rgba(0,0,0,.02)}

.contact p{color:var(--muted);margin-top:8px}

/* Typography scaling */
.hero-left h1{font-size:36px;line-height:1.08}
.section-title{font-size:26px;text-align:center}
/* Ensure all h2 are centered by default */
h2{ text-align:center; }

@media (max-width:900px){
  .hero-left h1{font-size:32px}
  .section-title{font-size:22px}
}
@media (max-width:700px){
  .hero-left h1{font-size:26px}
  .section-title{font-size:20px}
  .header .nav-row{padding:12px 0}
  .brand img{height:32px}
}
.cta-inner{display:flex;justify-content:space-between;align-items:center;gap:20px}
.badges{display:flex;gap:12px;margin-top:12px}
.badge{display:inline-block;padding:8px 12px;border-radius:8px;color:#fff;text-decoration:none}
.badge.android{background:#3ddc84}
.badge.ios{background:#0a84ff}

.footer{padding:36px 0;text-align:center;color:var(--muted);background:#fff;margin-top:60px;border-top:1px solid rgba(0,0,0,.04)}

/* 响应式 */
@media (max-width:900px){
  .hero-inner{grid-template-columns:1fr 320px}
  .features-grid{grid-template-columns:repeat(2,1fr)}
  .hero::before{display:none}
}
@media (max-width:700px){
  .cta-inner{flex-direction:column;align-items:flex-start}
  /* Keep KPIs horizontal on small screens; allow horizontal scroll if needed */
  .kpis{
    flex-direction:row;
    overflow-x:auto;
    -webkit-overflow-scrolling:touch;
    gap:12px;
    padding-bottom:6px;
  }
  .kpis::-webkit-scrollbar{height:6px}
  .kpis .kpi{min-width:110px;flex:0 0 auto}
  .how .steps{flex-direction:column}
  .screens-grid{grid-template-columns:1fr}
}

@media (max-width:700px){
  .container{padding:0 14px}
  .nav-menu{position:absolute;top:68px;left:0;right:0;background:#fff;padding:0 14px;border-top:1px solid #eee;overflow:hidden;max-height:0;transition:max-height .28s ease;z-index:35}
  .nav-menu.open{padding:14px;max-height:420px}
  .nav-menu ul{flex-direction:column;gap:8px}
  .nav-menu a{display:block;padding:10px 8px}
  .mobile-toggle{display:block}
  .mobile-toggle .bar{transition:transform .2s ease,opacity .2s ease}
  .mobile-toggle.active .bar:nth-child(1){transform:translateY(6px) rotate(45deg)}
  .mobile-toggle.active .bar:nth-child(2){opacity:0}
  .mobile-toggle.active .bar:nth-child(3){transform:translateY(-6px) rotate(-45deg)}
  .hero-inner{grid-template-columns:1fr;gap:20px}
  .hero{padding-top:108px}
  .features-grid{grid-template-columns:1fr}
  .screens-grid{grid-template-columns:1fr}
}