:root{
  --bg1:#d9f0ff; --bg2:#fff6d6;
  --padat:#c0763a; --cair:#2f8fe0; --gas:#7b61d9;
  --ok:#2e9e5b; --bad:#e04b4b; --ink:#25324a;
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
html,body{margin:0;min-height:100%;font-family:"Comic Sans MS","Trebuchet MS","Segoe UI",Arial,sans-serif;color:var(--ink)}
body{background:linear-gradient(160deg,var(--bg1),var(--bg2));min-height:100vh}
#app{max-width:900px;margin:0 auto;padding:12px 14px 30px;min-height:100vh}
.hidden{display:none!important}

/* top bar */
#topbar{display:flex;align-items:center;gap:10px;margin-bottom:12px}
.icon-btn{border:0;background:#fff;border-radius:50%;width:44px;height:44px;font-size:22px;box-shadow:0 3px 0 #0002;cursor:pointer}
#progress-wrap{flex:1;height:16px;background:#fff;border-radius:99px;overflow:hidden;box-shadow:inset 0 1px 3px #0003}
#progress-bar{height:100%;width:0;background:linear-gradient(90deg,#ffb347,#ffcc33);border-radius:99px;transition:width .4s}
#score-box{background:#fff;border-radius:99px;padding:8px 14px;font-weight:700;box-shadow:0 3px 0 #0002}

/* screens */
.screen{display:none;animation:pop .35s ease}
.screen.active{display:block}
@keyframes pop{from{opacity:0;transform:translateY(12px) scale(.98)}to{opacity:1;transform:none}}

.hero{text-align:center;padding:30px 10px}
.hero h1{font-size:clamp(34px,8vw,60px);line-height:1.05;margin:10px 0;color:#1d5fa8;text-shadow:3px 3px 0 #fff}
.subtitle{font-size:18px;font-weight:700;margin-bottom:26px}
.floaties{font-size:56px;display:flex;justify-content:center;gap:18px}
.floaties span{animation:float 2.4s ease-in-out infinite}
.floaties span:nth-child(2){animation-delay:.4s}
.floaties span:nth-child(3){animation-delay:.8s}
@keyframes float{50%{transform:translateY(-14px)}}

.card{background:#fff;border-radius:24px;padding:22px;box-shadow:0 6px 0 #0002;max-width:640px;margin:10px auto}
.card.wide{max-width:860px}
.card.center{text-align:center}
.card h2{margin-top:0;color:#1d5fa8}

/* buttons */
.btn{display:inline-block;border:0;border-radius:16px;background:#ff9f1c;color:#fff;font:inherit;font-weight:700;font-size:18px;padding:12px 24px;margin:6px;cursor:pointer;box-shadow:0 5px 0 #c97800;transition:transform .08s}
.btn:active{transform:translateY(4px);box-shadow:0 1px 0 #c97800}
.btn.big{font-size:24px;padding:16px 34px}
.btn.secondary{background:#2f8fe0;box-shadow:0 5px 0 #1c64a8}
.btn.ghost{background:#8a97ad;box-shadow:0 5px 0 #66728a}

.level-tag{display:inline-block;background:#eaf4ff;color:#1d5fa8;font-weight:700;border-radius:99px;padding:6px 14px;margin-bottom:8px}
.instruksi,.question{font-size:clamp(20px,4vw,26px);font-weight:700;margin:10px 0}

/* materi */
.cols{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:12px;margin:14px 0}
.mat{border-radius:18px;padding:14px;color:#fff}
.mat.padat{background:var(--padat)} .mat.cair{background:var(--cair)} .mat.gas{background:var(--gas)}
.mat .emo{font-size:46px;text-align:center}
.mat h3{margin:4px 0;text-align:center;font-size:24px}
.mat ul{padding-left:20px;margin:8px 0}
.fact{background:#fff6d6;border-radius:14px;padding:12px}
.steps li{margin-bottom:8px}

/* level 1 */
.item-card{text-align:center;background:#f4f9ff;border:3px dashed #9cc7f0;border-radius:22px;padding:18px;margin:12px 0}
.item-emoji{font-size:clamp(70px,18vw,110px);line-height:1}
.item-name{font-size:clamp(22px,5vw,30px);font-weight:700;margin-top:6px}
.item-card.bounce{animation:bounce .5s}
@keyframes bounce{30%{transform:scale(1.08)}60%{transform:scale(.96)}}
.item-card.shake{animation:shake .4s}
@keyframes shake{25%{transform:translateX(-10px)}75%{transform:translateX(10px)}}

.buckets{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.bucket{border:0;border-radius:20px;color:#fff;font:inherit;font-weight:800;font-size:clamp(16px,4vw,22px);padding:14px 4px;cursor:pointer;box-shadow:0 6px 0 #0003;transition:transform .08s}
.bucket span{display:block;font-size:clamp(34px,9vw,52px)}
.bucket:active{transform:translateY(4px)}
.bucket.padat{background:var(--padat)} .bucket.cair{background:var(--cair)} .bucket.gas{background:var(--gas)}
.bucket:disabled{opacity:.6}

/* options */
.options{display:grid;gap:10px;margin:10px 0}
.opt{border:3px solid #cfe3f7;background:#f4f9ff;border-radius:16px;padding:14px;font:inherit;font-size:19px;font-weight:700;text-align:left;cursor:pointer;color:var(--ink)}
.opt:hover{background:#e3f1ff}
.opt.correct{background:#d5f5e1;border-color:var(--ok)}
.opt.wrong{background:#fde0e0;border-color:var(--bad)}
.opt:disabled{cursor:default}

.tf-row{display:flex;gap:10px;flex-wrap:wrap;justify-content:center;margin:10px 0}
.btn.tf{flex:1;min-width:140px;font-size:22px}
.btn.benar{background:var(--ok);box-shadow:0 5px 0 #1b6e3d}
.btn.salah{background:var(--bad);box-shadow:0 5px 0 #a02f2f}
.btn:disabled{opacity:.55}

.feedback{min-height:28px;font-size:18px;font-weight:700;margin:10px 0;border-radius:14px}
.feedback.ok{color:var(--ok);background:#eafaf0;padding:10px}
.feedback.bad{color:var(--bad);background:#fff0f0;padding:10px}

.big-emoji{font-size:84px}
.stars{font-size:54px;margin:6px 0}
.res-score{font-size:20px}

@media (max-width:480px){
  .card{padding:16px}
  .btn{font-size:16px}
}