:root{
  --bg: #0f1724;
  --card: #0b1220cc;
  --accent: #00d4ff;
  --good: #26d07b;
  --bad: #ff5c6c;
  --muted: #9aa4b2;
}
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;font-family:Inter,system-ui,Arial,sans-serif;background:linear-gradient(180deg,#081021 0%, #0f1724 100%);color:#e6eef6;display:flex;align-items:center;justify-content:center;}
.game-wrap{width:100%;max-width:1100px;padding:24px}
.hud{display:flex;justify-content:space-between;align-items:center;margin-bottom:14px}
.hud .score,.hud .level{font-weight:600;background:rgba(255,255,255,0.04);padding:8px 12px;border-radius:10px}
.game-btn{border:0;padding:8px 16px;border-radius:8px;font-weight:600;cursor:pointer;transition:all .2s;font-size:14px}
.reset-btn{background:rgba(255,92,108,0.1);color:var(--bad);border:1px solid rgba(255,92,108,0.3)}
.reset-btn:hover{background:rgba(255,92,108,0.2);transform:translateY(-1px)}
.start-btn{background:var(--accent);color:#fff;font-size:18px;padding:12px 24px;border-radius:12px;box-shadow:0 4px 12px rgba(0,212,255,0.3)}
.start-btn:hover{background:#00b8e6;transform:translateY(-2px);box-shadow:0 6px 20px rgba(0,212,255,0.4)}
.nav-section{display:flex;justify-content:center;align-items:center;margin-bottom:16px;padding:16px 0;background:var(--card);backdrop-filter:blur(6px);border-radius:12px}
.nav-content{text-align:center}
.nav-line{font-size:24px;font-weight:700;color:#fff}
.nav-line.small{font-size:14px;color:var(--muted);margin-top:4px;font-weight:400}
.timer-section{display:flex;gap:16px;align-items:center;justify-content:center;margin-bottom:18px;padding:12px 0}
.timer-section .time-left{font-size:18px;font-weight:600;color:var(--accent)}
.timer-section .timer-bar-wrap{width:300px;height:14px;background:rgba(255,255,255,0.06);border-radius:8px;overflow:hidden}
.timer-section .timer-bar{height:100%;width:100%;background:linear-gradient(90deg,var(--accent),#8bdcff);transform-origin:left}
.stage{position:relative;height:480px;border-radius:18px;overflow:hidden;background:radial-gradient(1200px 600px at 20% 20%, rgba(0,212,255,0.05), transparent), linear-gradient(180deg, rgba(255,255,255,0.02), transparent);}
.start-screen{position:absolute;inset:0;display:flex;align-items:center;justify-content:center;background:rgba(11,18,32,0.9);backdrop-filter:blur(8px);z-index:20}
.start-content{text-align:center;padding:40px;background:var(--card);border-radius:20px;box-shadow:0 20px 40px rgba(2,6,23,0.8)}
.start-content h2{margin:0 0 16px;font-size:32px;color:var(--accent)}
.start-content p{margin:0 0 24px;color:var(--muted);font-size:16px}
.final-score{font-size:28px;font-weight:700;color:var(--accent);margin:20px 0}
.score-message{font-size:18px;color:var(--good);margin:16px 0 24px}
.start-screen.hidden{display:none}
.bubbles{position:absolute;inset:0;pointer-events:none}
.bubble{pointer-events:auto;position:absolute;border-radius:999px;border:0;padding:18px 22px;font-size:20px;background:linear-gradient(180deg,rgba(255,255,255,0.06),rgba(255,255,255,0.02));color:#fff;box-shadow:0 8px 20px rgba(2,6,23,0.5);cursor:pointer;transition:all .3s ease}
.bubble:active{transform:scale(.95)}
.bubble:hover{background:linear-gradient(180deg,rgba(255,255,255,0.12),rgba(255,255,255,0.06));transform:translateY(-2px);box-shadow:0 12px 28px rgba(2,6,23,0.7)}
.bubble.disabled{background:linear-gradient(180deg,rgba(38,208,123,0.3),rgba(38,208,123,0.1));border:2px solid var(--good);color:#fff;cursor:default;transform:scale(0.9)}
.bubble.disabled:hover{transform:scale(0.9)}
.bubble.big{padding:22px 26px;font-size:22px}

/* floating variants */
@keyframes floatY{0%{transform:translateY(0)}50%{transform:translateY(-18px)}100%{transform:translateY(0)}}
@keyframes floatX{0%{transform:translateX(0)}50%{transform:translateX(12px)}100%{transform:translateX(0)}}
.flash{position:fixed;inset:0;pointer-events:none;z-index:40;opacity:0;transition:opacity .18s}
.flash.show-correct{background:linear-gradient(90deg, rgba(38,208,123,0.12), rgba(38,208,123,0.06));opacity:1}
.flash.show-wrong{background:linear-gradient(90deg, rgba(255,92,108,0.12), rgba(255,92,108,0.06));opacity:1}

.notes{margin-top:12px;text-align:center;color:var(--muted)}

/* positions for three bubbles roughly around center-box */
.bubble{font-weight:600}
.bubble[data-id="0"]{left:14%;top:16%;width:150px;height:150px;border-radius:75px;animation:floatY 4.3s ease-in-out infinite;font-size:20px}
.bubble[data-id="1"]{right:12%;top:12%;width:180px;height:180px;border-radius:90px;animation:floatX 5.2s ease-in-out infinite;font-size:22px}
.bubble[data-id="2"]{left:36%;bottom:12%;width:164px;height:164px;border-radius:82px;animation:floatY 4.7s ease-in-out infinite;font-size:20px}

/* small responsive tweaks */
@media (max-width:720px){
  .center-box{width:300px;height:200px}
  .bubble{width:120px;height:120px;font-size:16px}
  .bubble[data-id="1"]{width:140px;height:140px}
  .bubble[data-id="0"]{left:12%;top:10%}
  .bubble[data-id="2"]{left:34%;bottom:8%}
}