:root { --bg:#111; --card:#1c1c1c; --gold:#c9a227; --text:#eee; --muted:#999; }
* { box-sizing: border-box; }
body { margin:0; background:var(--bg); color:var(--text);
       font:16px/1.5 system-ui, -apple-system, "Segoe UI", sans-serif; }
.top { display:flex; justify-content:space-between; align-items:center;
       padding:12px 16px; border-bottom:1px solid #333; }
.brand { color:var(--gold); text-decoration:none; font-weight:700; letter-spacing:.05em; }
.top nav a { color:var(--text); text-decoration:none; padding:8px 14px;
             border:1px solid var(--gold); border-radius:8px; }
main { padding:16px; max-width:720px; margin:0 auto; }
h1 { font-size:1.3rem; }
.card { background:var(--card); border:1px solid #333; border-radius:12px;
        padding:16px; margin:12px 0; }
label { display:block; margin:10px 0 4px; color:var(--muted); }
input, select { width:100%; padding:12px; border-radius:8px; border:1px solid #444;
                background:#222; color:var(--text); font-size:16px; }
button { margin-top:14px; width:100%; padding:14px; border:0; border-radius:10px;
         background:var(--gold); color:#111; font-weight:700; font-size:16px; }
button.copy { background:#333; color:var(--gold); border:1px solid var(--gold); }
button.check { width:auto; margin:0 0 0 8px; padding:6px 14px; font-size:14px; vertical-align:middle; }
a.back { display:inline-block; margin-bottom:4px; color:var(--muted); text-decoration:none; }
.error { color:#e66; }
.muted { color:var(--muted); font-size:.9rem; }
a { color:var(--gold); }
ul.plain { list-style:none; padding:0; }
ul.plain li { padding:12px; border-bottom:1px solid #2a2a2a; }