:root { --max: 80rem; --b:#e5e7eb; --txt:#111827; --muted:#6b7280; }
*{box-sizing:border-box} body{margin:0;color:var(--txt);font:16px/1.5 ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,Arial}
a{text-decoration:none;color:inherit}
header{border-bottom:1px solid var(--b)}
.container{max-width:var(--max);margin:0 auto;padding:1rem}
.btn{background:#000;color:#fff;border-radius:1rem;padding:.75rem 1.25rem;display:inline-block}
.card{border:1px solid var(--b);border-radius:1rem;padding:1.25rem}
.grid{display:grid;gap:2rem}
.grid-3{grid-template-columns:1fr}
@media(min-width:640px){.grid-3{grid-template-columns:repeat(3,1fr)}}
input,textarea{width:100%;padding:.75rem;border:1px solid var(--b);border-radius:.75rem}
h1{font-size:1.75rem;margin:1rem 0 .25rem}
h2{font-size:1.1rem;margin:.25rem 0}
.muted{color:var(--muted)}
.hidden{display:none}