/* Modern, minimal stylesheet */
:root{
  --bg:#f6f7fb;
  --card:#ffffff;
  --muted:#6b7280;
  --accent:#2563eb;
  --border:#e6e9f0;
  --radius:10px;
  --container:1100px;
}

*{box-sizing:border-box}
body{font-family:Inter, system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial; background:var(--bg); color:#0f172a; margin:0; padding:0; -webkit-font-smoothing:antialiased;}
.topbar{background:linear-gradient(90deg,#ffffff,#f8fafc);border-bottom:1px solid var(--border);display:flex;align-items:center;justify-content:space-between;padding:14px 22px;position:sticky;top:0;z-index:3;}
.brand{font-weight:700;font-size:16px;}
.nav a{margin-left:14px;color:var(--accent);text-decoration:none;font-weight:600}
.container{max-width:var(--container);margin:28px auto;padding:0 16px;}
h1{font-size:22px;margin-bottom:10px}
.cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:16px;margin-top:12px}
.card{background:var(--card);border:1px solid var(--border);padding:16px;border-radius:var(--radius);box-shadow:0 6px 18px rgba(2,6,23,0.04)}
.card h3{margin:0 0 8px 0;font-size:16px}
.card .meta{font-size:13px;color:var(--muted)}

.topic{background:var(--card);padding:18px;border-radius:var(--radius);border:1px solid var(--border);margin-bottom:14px}
.replies .reply{background:var(--card);border:1px solid var(--border);padding:12px;border-radius:8px;margin-bottom:10px}
.reply .meta{color:var(--muted);font-size:12px;margin-top:8px}

.form{background:var(--card);padding:14px;border-radius:8px;border:1px solid var(--border);margin-top:12px}
label{display:block;margin-bottom:8px;font-weight:600;color:#111827}
input, textarea{width:100%;padding:10px;border-radius:8px;border:1px solid var(--border);background:#fff;margin-bottom:12px;font-size:14px}
button{background:var(--accent);color:#fff;border:none;padding:10px 14px;border-radius:8px;font-weight:700;cursor:pointer}
.alert{background:#fee2e2;color:#991b1b;padding:10px;border-radius:8px;margin-bottom:12px}
.footer{max-width:var(--container);margin:30px auto;padding:16px;color:var(--muted);text-align:center;font-size:13px}
@media (max-width:600px){.cards{grid-template-columns:1fr} .topbar{padding:10px}}