:root{
  --bg: #0f1724;
  --card: #0b1220;
  --accent: #ff9f1c;
  --accent-2: #6ee7b7;
  --muted: #98a2b3;
  --glass: rgba(255,255,255,0.04);
  --glow: 0 6px 24px rgba(159,108,255,0.12);
  --glass-2: rgba(255,255,255,0.03);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
}

*{box-sizing:border-box}
html,body{height:100%;margin:0;background:
linear-gradient(180deg,#071029 0%, #071826 60%), url('https://source.unsplash.com/1600x900/?technology,pattern') center/cover no-repeat fixed; color:#e6eef8}
.nl-app{max-width:1200px;margin:28px auto;padding:20px;display:grid;grid-template-columns:1fr 320px;gap:22px;align-items:start}
.nl-header{grid-column:1/-1;display:flex;justify-content:space-between;align-items:center;padding:18px;background:linear-gradient(180deg, rgba(255,255,255,0.02), rgba(255,255,255,0.01));border-radius:14px;box-shadow:var(--glow)}
.nl-title{margin:0;font-size:20px;display:flex;gap:10px;align-items:center}
.nl-sub{margin:0;color:var(--muted);font-size:13px}
.nl-controls{display:flex;flex-direction:column;gap:10px;align-items:flex-end}
.nl-stats{display:flex;gap:14px;align-items:center;font-weight:600}
.nl-stats div{background:var(--glass);padding:8px 12px;border-radius:10px;color:var(--accent-2);font-size:13px}
.btn{background:transparent;border:1px solid rgba(255,255,255,0.06);padding:8px 12px;border-radius:8px;color:inherit;cursor:pointer;font-weight:700}
.btn.primary{background:linear-gradient(90deg,var(--accent),#ff6b6b);border:none;color:#08101a;box-shadow:0 6px 18px rgba(255,159,28,0.18)}
.btn.danger{background:transparent;border:1px solid rgba(255,80,80,0.18);color:#ffb3b3}
.nl-main{background: linear-gradient(180deg, rgba(255,255,255,0.02), rgba(0,0,0,0.05));padding:18px;border-radius:12px;box-shadow:var(--glow)}
.lock-area{display:flex;gap:18px;align-items:center}
.lock-visual{position:relative;width:420px;height:260px;border-radius:10px;overflow:hidden;border:1px solid rgba(255,255,255,0.03);background:linear-gradient(180deg, rgba(0,0,0,0.25), rgba(255,255,255,0.01))}
.lock-image{width:100%;height:100%;object-fit:cover;filter:contrast(0.9) saturate(1.05) brightness(.9)}
.code-display{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);display:flex;gap:10px;backdrop-filter:blur(6px);padding:10px;border-radius:12px;background:linear-gradient(90deg, rgba(0,0,0,0.45), rgba(255,255,255,0.02));box-shadow:0 8px 30px rgba(0,0,0,0.6)}
.code-digit{width:56px;height:66px;border-radius:8px;display:flex;align-items:center;justify-content:center;font-size:28px;font-weight:800;background:linear-gradient(180deg, rgba(255,255,255,0.03), rgba(0,0,0,0.3));color:#fff;border:1px solid rgba(255,255,255,0.06);box-shadow:0 6px 18px rgba(0,0,0,0.5)}
.code-digit.hidden{color:transparent;letter-spacing:8px;position:relative}
.code-digit.hidden::after{content:"•";color:rgba(255,255,255,0.2);font-size:32px;position:absolute}
.code-digit.revealed{background:linear-gradient(90deg,var(--accent-2),#fff);color:#07101a}
.timer-panel{min-width:240px;padding:12px;border-radius:10px;background:var(--glass);display:flex;flex-direction:column;gap:12px}
.timer-row{display:flex;justify-content:space-between;align-items:center;font-weight:700}
#timer{font-size:20px;color:var(--accent-2)}
.progress{background:var(--glass-2);height:12px;border-radius:8px;overflow:hidden}
.progress-bar{height:100%;width:0%;background:linear-gradient(90deg,var(--accent),#ff6b6b)}
.puzzle-area{margin-top:20px;display:block;padding:12px;border-radius:12px;background:linear-gradient(180deg, rgba(255,255,255,0.02), rgba(0,0,0,0.04))}
.puzzle-header h2{margin:6px 0 12px 0;color:var(--accent)}
.puzzle-body{min-height:180px;display:flex;gap:12px;align-items:center}
.puzzle-illu{width:220px;height:140px;object-fit:cover;border-radius:10px;box-shadow:0 10px 30px rgba(4,6,10,0.6)}
.puzzle-instruction{flex:1;color:var(--muted)}
.puzzle-actions{display:flex;gap:12px;align-items:center;margin-top:12px}
.feedback{min-width:220px;color:var(--accent-2);font-weight:700}
.nl-side{padding:16px;border-radius:12px;background:linear-gradient(180deg, rgba(255,255,255,0.02), rgba(0,0,0,0.02))}
.level-legend h3,.sound-controls h3,.instructions h3{margin:0 0 8px 0;color:var(--muted)}
.nl-footer{grid-column:1/-1;color:var(--muted);text-align:center;margin-top:10px}
@media(max-width:980px){
  .nl-app{grid-template-columns:1fr; padding:12px}
  .nl-main{order:2}
  .nl-side{order:1}
}