:root{--bg:#ffffff;--ink:#111827;--muted:#6b7280;--brand:#0ea5e9;--card:#f8fafc}
*{box-sizing:border-box} body{margin:0;font-family:Inter,system-ui,Segoe UI,Roboto,Arial,sans-serif;background:var(--bg);color:var(--ink)}
a{color:var(--brand);text-decoration:none}
header{background:#fff;position:sticky;top:0;z-index:10;border-bottom:1px solid #e5e7eb}
.container{max-width:1100px;margin:0 auto;padding:1.25rem}
nav a{margin-right:1rem;padding:.5rem .75rem;border-radius:.75rem}
nav a.active{background:var(--card)}
.grid{display:grid;gap:1rem}
.grid-3{grid-template-columns:repeat(auto-fill,minmax(280px,1fr))}
.card{background:var(--card);border-radius:1rem;padding:1rem;border:1px solid #e5e7eb}
.hero{padding:3rem 0}
.btn{display:inline-block;background:var(--brand);color:#fff;padding:.75rem 1rem;border-radius:.75rem}
.muted{color:var(--muted)}
img{max-width:100%;height:auto;border-radius:.75rem}
form .field{margin-bottom:1rem}
input,textarea{width:100%;padding:.75rem;border:1px solid #e5e7eb;border-radius:.75rem}
footer{margin-top:3rem;border-top:1px solid #e5e7eb}
small.error{color:#b91c1c}