body{font-family:system-ui,Arial,sans-serif;margin:0;padding:16px}
header{display:flex;gap:12px;align-items:center;justify-content:space-between;margin-bottom:16px}
main{display:grid;grid-template-columns:2fr 1fr;gap:16px}
#catalog{display:grid;grid-template-columns:repeat(3,1fr);gap:12px}
.card{border:1px solid #ddd;border-radius:8px;padding:12px}
.card h3{margin:.2rem 0}
@media (max-width:900px){ main{grid-template-columns:1fr} #catalog{grid-template-columns:repeat(2,1fr)} }
@media (max-width:560px){ #catalog{grid-template-columns:1fr} }