:root{
  --bg:#0b1320;
  --panel:rgba(0,0,0,.35);
  --text:#e9eef7;
  --muted:#cfd7e6;
  --btn:#1b2231;
  --btn2:#2a344b;
  --accent:#8cc8ff;
  --danger:#e34b4b;
  --radius:14px;
}
*{box-sizing:border-box;}
html,body{height:100%; margin:0; background:#111; color:var(--text); font-family:system-ui,-apple-system,"Hiragino Sans",sans-serif; overflow:hidden; touch-action:none;}
#app{height:100%; display:flex; flex-direction:column; align-items:center; justify-content:space-between; gap:10px; padding:10px;}
#topbar{
  width:min(460px, 100%);
  display:flex; align-items:center; justify-content:space-between; gap:8px;
  padding:10px 12px; border-radius:var(--radius);
  background:var(--panel); backdrop-filter: blur(8px);
}
#stats{font-size:13px; line-height:1.35; text-align:left;}
#stats b{font-weight:700;}
#topbar .right{display:flex; gap:8px; align-items:center;}
button.icon{
  border:0; border-radius:12px; padding:10px 12px;
  background:var(--btn); color:var(--text); font-size:14px;
}
button.icon:active{transform:scale(.98); background:var(--btn2);}
#stage{
  width:min(460px, 100%);
  display:flex; justify-content:center; gap:10px;
}
#gameWrap{
  position:relative;
  background:var(--bg);
  border-radius:var(--radius);
  overflow:hidden;
  box-shadow: 0 10px 30px rgba(0,0,0,.35);
}
canvas{display:block;}
#side{
  width:120px;
  display:flex; flex-direction:column; gap:10px;
}
.panel{
  background:var(--panel);
  border-radius:var(--radius);
  padding:10px;
  font-size:12px;
}
.panel h4{margin:0 0 8px; font-size:12px; letter-spacing:.2px; color:var(--muted);}
.mini{
  width:100%; aspect-ratio: 1 / 1;
  background:rgba(0,0,0,.25);
  border-radius:12px;
  display:flex; align-items:center; justify-content:center;
}
#controls{
  width:min(460px, 100%);
  display:grid;
  grid-template-columns: repeat(4, 1fr);
  gap:10px;
  padding-bottom: env(safe-area-inset-bottom);
}
#controls button{
  border:0; border-radius:16px;
  padding:14px 10px;
  background:var(--btn);
  color:var(--text);
  font-size:16px;
  font-weight:600;
}
#controls button:active{transform:scale(.98); background:var(--btn2);}
#controls button.secondary{background:#202a3e;}
#controls button.secondary:active{background:#2a3550;}
#controls button.danger{background:#4b2020;}
#controls button.danger:active{background:#5a2a2a;}
#overlay{
  position:fixed; inset:0;
  display:flex; align-items:center; justify-content:center;
  background:rgba(0,0,0,.72);
  padding:16px;
}
#overlay.hidden{display:none;}
.card{
  width:min(520px, 100%);
  background:#0f1727;
  border-radius:18px;
  padding:16px;
  box-shadow: 0 20px 60px rgba(0,0,0,.5);
  border: 1px solid rgba(255,255,255,.06);
}
.card h2{margin:0 0 10px; font-size:18px;}
.card p{margin:8px 0; color:var(--muted); font-size:14px; line-height:1.5;}
.card ul{margin:10px 0 0; padding-left:18px; color:var(--muted); font-size:14px; line-height:1.55;}
.card .row{display:flex; gap:10px; flex-wrap:wrap; margin-top:14px;}
.card .row button{flex:1; min-width:120px;}
.small{font-size:12px; color:var(--muted);}
.badge{display:inline-block; padding:3px 8px; border-radius:999px; background:rgba(140,200,255,.15); color:var(--accent); font-size:12px; margin-left:8px;}
#toast{
  position:fixed; left:50%; bottom:90px; transform:translateX(-50%);
  background:rgba(0,0,0,.55); color:#fff;
  padding:10px 12px; border-radius:999px;
  font-size:13px; opacity:0; transition:.2s;
  pointer-events:none;
}
#toast.show{opacity:1;}
@media (max-width:420px){
  #side{display:none;}
}

/* v2 tweaks */
.card .row button{
  padding:12px 14px;
  font-size:15px;
}
.card .row button.primary{
  background: rgba(140,200,255,.18);
  color: var(--text);
  border: 1px solid rgba(140,200,255,.35);
}
.card .row button.primary:active{background: rgba(140,200,255,.28);}
.card .row button.exit{
  background: rgba(227,75,75,.18);
  border: 1px solid rgba(227,75,75,.35);
}
.card .row button.exit:active{background: rgba(227,75,75,.28);}
.card .hero{
  display:flex;
  flex-direction:column;
  gap:8px;
  padding:10px 12px;
  border-radius:16px;
  background: rgba(0,0,0,.22);
  border: 1px solid rgba(255,255,255,.06);
  margin: 10px 0 14px;
}
.card .hero .title{
  font-size:22px;
  font-weight:800;
  letter-spacing:.3px;
}
.card .hero .sub{
  font-size:13px;
  color: var(--muted);
  line-height:1.5;
}

/* v3 difficulty */
.diff-grid{
  display:grid;
  grid-template-columns: 1fr;
  gap:10px;
  margin: 10px 0 6px;
}
.diff-grid button{
  width:100%;
  border-radius:16px;
  padding:14px 14px;
  font-size:16px;
  font-weight:800;
}
.diff-grid button.easy{background: rgba(123,220,140,.18); border:1px solid rgba(123,220,140,.35);}
.diff-grid button.easy:active{background: rgba(123,220,140,.28);}
.diff-grid button.normal{background: rgba(140,200,255,.18); border:1px solid rgba(140,200,255,.35);}
.diff-grid button.normal:active{background: rgba(140,200,255,.28);}
.diff-grid button.hard{background: rgba(227,75,75,.18); border:1px solid rgba(227,75,75,.35);}
.diff-grid button.hard:active{background: rgba(227,75,75,.28);}
.kv{
  display:flex; flex-wrap:wrap; gap:8px; margin-top:10px;
}
.kv span{
  background: rgba(255,255,255,.06);
  border:1px solid rgba(255,255,255,.08);
  padding:6px 10px; border-radius:999px; font-size:12px; color:var(--muted);
}
/* v4: slightly tighter layout to enlarge the playfield */
#app{padding:8px;}
#stage{gap:8px;}


/* v13: prevent long-press selection / context menu on mobile */
html, body, #app, #stage, #controls, canvas, button, .panel, .card {
  -webkit-user-select: none;
  user-select: none;
  -webkit-touch-callout: none; /* iOS long-press menu */
}
button, canvas {
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
}
#controls button {
  touch-action: manipulation;
}