:root{--bg: #0f172a;--card: #111827;--muted: #9ca3af;--text: #e5e7eb;--accent: #22c55e;--accent-2: #2563eb;--danger: #ef4444;--border: #1f2937;--shadow: 0 10px 30px rgba(0,0,0,.35)}*{box-sizing:border-box}body{margin:0;font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,Ubuntu,Cantarell,Helvetica Neue,Arial;background:linear-gradient(180deg,#0b1022,var(--bg));color:var(--text)}.container{max-width:860px;margin:40px auto;padding:0 16px}.header h1{margin:0 0 8px;font-size:2rem;letter-spacing:.3px}.header p{margin:0 0 24px;color:var(--muted)}.card{background:var(--card);border:1px solid var(--border);border-radius:16px;padding:24px;box-shadow:var(--shadow)}form{display:grid;gap:16px}.field{display:grid;gap:8px}label{font-weight:600}input[type=text],input[type=email],input[type=number],select,textarea{background:#0b1220;color:var(--text);border:1px solid var(--border);border-radius:10px;padding:12px 14px;outline:none;transition:border-color .2s ease,box-shadow .2s ease}input:focus,select:focus,textarea:focus{border-color:var(--accent-2);box-shadow:0 0 0 3px #2563eb40}.checkline{display:flex;align-items:center;gap:10px}.error{margin:6px 0 0;color:var(--danger);font-size:.95rem}.actions{display:flex;gap:12px}button{border:none;border-radius:12px;padding:12px 18px;font-weight:700;cursor:pointer;background:var(--accent);color:#052e16;box-shadow:var(--shadow);transition:transform .05s ease,opacity .2s ease}button.secondary{background:#1f2937;color:var(--text)}button:active{transform:translateY(1px)}button[disabled]{opacity:.5;cursor:not-allowed}.result{margin-top:24px;border:1px solid var(--border);border-radius:12px;padding:16px;background:#0b1220}.result.ok{border-color:#14532d}.result.error{border-color:#7f1d1d}.footer{margin-top:24px;color:var(--muted);text-align:center}pre{white-space:pre-wrap;word-wrap:break-word;background:#0a0f1e;padding:12px;border-radius:8px;border:1px solid var(--border)}