*{box-sizing:border-box}
:root{--bg:#0c0f14;--card:#121826;--border:#293245;--text:#e8eef6;--muted:#9fb3ce}
html,body{margin:0;height:100%}
body{font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;background:var(--bg);color:var(--text)}
main{max-width:880px;margin:28px auto;padding:0 16px}
h1{font-size:28px;margin:0 0 6px}
.sub{margin:0 0 18px;color:var(--muted)}
.card{background:var(--card);border:1px solid var(--border);border-radius:18px;box-shadow:0 10px 30px rgba(0,0,0,.35);padding:16px}
.row{display:flex;gap:12px;flex-wrap:wrap;align-items:center}
button{background:#182439;border:1px solid #2e4160;color:var(--text);border-radius:12px;padding:12px 16px;font-weight:700;cursor:pointer}
button:hover{filter:brightness(1.08)}
.badge{display:inline-block;background:#0f1724;border:1px solid #2b3a53;border-radius:999px;padding:6px 10px;font-size:12px;color:var(--muted)}
.counter{font-weight:800}
.result{display:flex;gap:12px;align-items:center;padding:10px 12px;border:1px dashed #2b3a53;border-radius:12px;margin-top:10px}
.result .n{font-size:28px;font-weight:900;background:#0f1724;border:1px solid #2b3a53;border-radius:12px;min-width:52px;text-align:center;padding:6px 0}
.meta{display:flex;gap:8px;flex-wrap:wrap}
.small{font-size:12px;color:var(--muted)}
footer{opacity:.7;font-size:12px;margin:18px 0}
.hidden{display:none}