*{box-sizing:border-box}
body{
  margin:0;
  font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;
  line-height:1.65;
  color:#1e293b;
  background:linear-gradient(135deg,#f8fafc 0%,#e2e8f0 100%);
}
a{color:#2563eb;text-decoration:none}
a:hover{text-decoration:underline}
.container{max-width:960px;margin:0 auto;padding:0 20px}
header{
  position:sticky;top:0;z-index:30;
  background:rgba(255,255,255,0.95);
  backdrop-filter:blur(8px);
  border-bottom:1px solid #e2e8f0;
}
nav{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:14px 0}
.logo{font-size:1.3rem;font-weight:800;color:#2563eb}
.header-links{display:flex;gap:14px;flex-wrap:wrap;font-size:.92rem}
main{padding:40px 0 64px}
.article-wrap{
  background:#fff;
  border:1px solid #e2e8f0;
  border-radius:18px;
  padding:32px;
  box-shadow:0 8px 24px rgba(15,23,42,.08)
}
.breadcrumb{font-size:.9rem;color:#64748b;margin-bottom:14px}
h1{font-size:2rem;line-height:1.2;margin:0 0 14px}
.lead{font-size:1.08rem;color:#475569;border-left:4px solid #93c5fd;padding-left:14px;margin:0 0 18px}
.sublead{font-size:1.02rem;color:#475569;margin:0 0 18px}
.meta-row{font-size:.92rem;color:#64748b;margin:0 0 12px}
h2{font-size:1.35rem;margin:26px 0 10px;color:#0f172a}
p{margin:0 0 12px;color:#334155}
.mistakes{margin:0;padding-left:20px}
.mistakes li{margin:0 0 8px}
.cta-box{background:#eff6ff;border:1px solid #bfdbfe;border-radius:14px;padding:16px;margin:20px 0}
.cta-subtext{margin:0 0 12px;color:#334155}
.cta-buttons{display:flex;gap:10px;flex-wrap:wrap}
.btn{display:inline-block;padding:10px 14px;border-radius:10px;font-weight:600}
.btn-ios{background:#2563eb;color:#fff}
.btn-ios:hover{background:#1d4ed8;text-decoration:none}
.app-example{background:#f8fafc;border:1px solid #e2e8f0;border-radius:14px;padding:14px}
.related-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));gap:12px}
.related-card{display:block;background:#f8fafc;border:1px solid #e2e8f0;border-radius:12px;padding:14px;transition:.2s border-color,.2s transform}
.related-card:hover{border-color:#93c5fd;transform:translateY(-1px);text-decoration:none}
.related-card h3{font-size:1rem;margin:0 0 6px;color:#0f172a}
.related-card p{font-size:.92rem;margin:0;color:#64748b}
.link-list{padding-left:18px;margin:0}
.link-list li{margin:0 0 8px}
footer{padding:26px 0;border-top:1px solid #e2e8f0;background:#0f172a;color:#e2e8f0}
footer p{color:#cbd5e1;margin:0;text-align:center}
footer a{color:#93c5fd}
@media (max-width: 768px){
  nav{align-items:flex-start;flex-direction:column}
  .article-wrap{padding:22px}
  h1{font-size:1.7rem}
}