*{box-sizing:border-box}
body{margin:0;font:17px/1.65 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;color:#1d1d1f;background:#f5f5f7}
.wrap{max-width:860px;margin:0 auto;padding:0 20px}
header{background:#fff;border-bottom:1px solid #e3e3e8;position:sticky;top:0}
header .wrap{display:flex;align-items:center;justify-content:space-between;min-height:58px;flex-wrap:wrap}
.logo{font-weight:700;font-size:19px;color:#1d1d1f;text-decoration:none}
nav a{margin-left:20px;color:#515154;text-decoration:none;font-size:15px}
nav a:hover{color:#0066cc}
.hero{padding:54px 0 18px}
h1{font-size:34px;line-height:1.15;margin:0 0 14px;letter-spacing:-.01em}
.hero p{color:#515154;font-size:19px;margin:0;max-width:640px}
section{padding:26px 0}
h2{font-size:24px;margin:0 0 12px}
h3{font-size:17px;margin:0 0 6px}
ol,ul{padding-left:22px;margin:0}
li{margin-bottom:8px}
.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;margin-top:16px}
article{background:#fff;border:1px solid #e3e3e8;border-radius:14px;padding:18px}
article p{margin:0;color:#515154;font-size:15.5px}
details{background:#fff;border:1px solid #e3e3e8;border-radius:12px;padding:14px 18px;margin-bottom:10px}
summary{cursor:pointer;font-weight:600}
details p{margin:10px 0 0;color:#515154}
footer{margin-top:40px;padding:22px 0;border-top:1px solid #e3e3e8;color:#86868b;font-size:14px}
@media(max-width:600px){h1{font-size:27px}nav a{margin-left:12px}}