*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:"PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  color:#1a1a1a;
  background:#fff;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  font-size:16px;
}
img{display:block;max-width:100%;height:auto}
a{color:#2563eb;text-decoration:none}
a:hover{color:#1d4ed8;text-decoration:underline}
.wrap{width:min(1100px,calc(100% - 40px));margin:0 auto}

.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(255,255,255,.96);
  border-bottom:1px solid #eee;
  backdrop-filter:blur(8px);
}
.header-row{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:14px 0}
.brand{display:flex;align-items:center;gap:10px;color:#111;font-weight:700;font-size:16px}
.brand:hover{text-decoration:none;color:#111}
.brand img{border-radius:8px}
.top-nav{display:flex;gap:20px;flex-wrap:wrap}
.top-nav a{color:#555;font-size:14px;font-weight:500}
.top-nav a:hover{color:#111}
.menu-btn{display:none;border:1px solid #ddd;background:#fff;padding:8px 12px;border-radius:8px;font-size:18px;cursor:pointer;color:#444}
.mnav{display:none;flex-direction:column;padding:12px 0 16px;border-top:1px solid #f0f0f0}
.mnav.open{display:flex}
.mnav a{padding:10px 0;color:#444;font-size:15px;border-bottom:1px solid #f5f5f5}

.hero{
  padding:56px 0 48px;
  text-align:center;
  border-bottom:1px solid #f0f0f0;
}
.hero-badge{
  display:inline-block;
  padding:6px 14px;
  border-radius:999px;
  background:#eff6ff;
  color:#1d4ed8;
  font-size:13px;
  font-weight:600;
  margin-bottom:18px;
}
.hero h1{
  font-size:clamp(28px,5vw,42px);
  line-height:1.25;
  margin:0 0 18px;
  color:#111;
  font-weight:800;
  letter-spacing:-.02em;
}
.hero-lead{
  font-size:clamp(16px,2.5vw,18px);
  color:#555;
  max-width:720px;
  margin:0 auto 28px;
  line-height:1.8;
}
.hero-actions{display:flex;justify-content:center;gap:12px;flex-wrap:wrap;margin-bottom:24px}
.btn{
  display:inline-block;
  padding:12px 24px;
  border-radius:10px;
  font-size:15px;
  font-weight:600;
}
.btn-primary{background:#2563eb;color:#fff}
.btn-primary:hover{background:#1d4ed8;color:#fff;text-decoration:none}
.btn-outline{border:1px solid #d1d5db;color:#374151;background:#fff}
.btn-outline:hover{border-color:#9ca3af;color:#111;text-decoration:none}
.hero-visual{
  margin:32px auto 0;
  max-width:640px;
  border-radius:16px;
  overflow:hidden;
  border:1px solid #e5e7eb;
  box-shadow:0 12px 40px rgba(0,0,0,.06);
}
.hero-meta{font-size:13px;color:#999;margin-top:16px}

.features-3{padding:56px 0;background:#fff}
.features-3-head{text-align:center;margin-bottom:40px}
.features-3-head h2{font-size:clamp(22px,3.5vw,28px);margin:0 0 12px;color:#111;font-weight:700}
.features-3-head p{color:#666;margin:0;font-size:15px;max-width:560px;margin-inline:auto}
.feat-cols{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.feat-card{
  padding:28px 24px;
  border:1px solid #e8e8e8;
  border-radius:14px;
  background:#fff;
  transition:box-shadow .2s,border-color .2s;
}
.feat-card:hover{border-color:#bfdbfe;box-shadow:0 8px 28px rgba(37,99,235,.08)}
.feat-icon{
  width:52px;height:52px;border-radius:12px;background:#eff6ff;
  display:flex;align-items:center;justify-content:center;font-size:24px;margin-bottom:16px;
}
.feat-card h3{font-size:18px;margin:0 0 10px;color:#111;font-weight:700}
.feat-card p{margin:0;color:#555;font-size:15px;line-height:1.7}

.content-sec{padding:48px 0;border-top:1px solid #f0f0f0}
.content-sec.alt{background:#fafafa}
.sec-head{margin-bottom:28px}
.sec-head h2{font-size:24px;margin:0 0 10px;color:#111;font-weight:700}
.sec-head p{margin:0;color:#666;font-size:15px}
.prose p{margin:0 0 16px;color:#333;font-size:16px;line-height:1.85}
.prose h3{font-size:18px;margin:32px 0 12px;color:#222;font-weight:600}
.prose ul,.prose ol{margin:0 0 16px;padding-left:24px;color:#333}
.prose li{margin-bottom:8px;line-height:1.75}

.shots-row{display:grid;grid-template-columns:repeat(3,1fr);gap:16px;margin:28px 0}
.shots-row figure{margin:0;text-align:center}
.shots-row img{border-radius:10px;border:1px solid #e5e7eb;margin:0 auto}
.shots-row figcaption{font-size:12px;color:#888;margin-top:8px}

.link-row{display:flex;flex-wrap:wrap;gap:10px;margin:24px 0}
.link-chip{
  display:inline-block;padding:8px 16px;border:1px solid #dbeafe;border-radius:999px;
  font-size:14px;color:#1d4ed8;background:#f8fafc;
}
.link-chip:hover{background:#eff6ff;text-decoration:none}

.faq-list{margin-top:20px}
.faq-list details{border:1px solid #e8e8e8;border-radius:10px;padding:14px 18px;margin-bottom:10px;background:#fff}
.faq-list summary{cursor:pointer;font-weight:600;color:#222}
.faq-list p{margin:12px 0 0;color:#555;font-size:15px}

.site-footer{padding:40px 0 48px;border-top:1px solid #eee;text-align:center;font-size:14px;color:#888}
.site-footer a{color:#666;margin:0 10px}
.site-footer p{margin:16px 0 0}

.prose-page{padding:40px 0 56px;max-width:720px}
.prose-page h1{font-size:28px;margin:0 0 20px;color:#111;font-weight:700}
.prose-page h2{font-size:20px;margin:28px 0 12px;color:#222;font-weight:600}
.prose-page p,.prose-page li{color:#444;line-height:1.8}
.related-box{margin-top:36px;padding:20px;border:1px solid #e8e8e8;border-radius:12px;background:#fafafa}
.related-box h3{font-size:15px;margin:0 0 12px;color:#666;font-weight:600}
.related-box a{display:block;padding:6px 0;color:#2563eb}

.err-page{min-height:60vh;display:flex;align-items:center;justify-content:center;text-align:center;padding:48px 20px}
.err-page h1{font-size:48px;margin:0 0 12px;color:#111}

@media(max-width:900px){
  .feat-cols,.shots-row{grid-template-columns:1fr}
}
@media(max-width:768px){
  .top-nav{display:none}
  .menu-btn{display:block}
  .hero{padding:40px 0 36px}
  .features-3{padding:40px 0}
}