:root{
  --bg0:#070913;
  --bg1:#0b1024;
  --panel:rgba(16,20,40,.72);
  --panel2:rgba(12,14,28,.78);
  --border:rgba(122,168,255,.18);
  --text:#e9f0ff;
  --muted:rgba(233,240,255,.72);
  --accent:#2df2ff;
  --accent2:#8b5cff;
  --danger:#ff3d71;
  --good:#3cff8f;
  --shadow:0 18px 50px rgba(0,0,0,.45);
  --radius:16px;
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  color:var(--text);
  font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,Arial,"Apple Color Emoji","Segoe UI Emoji";
  background:
    radial-gradient(1100px 700px at 20% 10%, rgba(45,242,255,.18), transparent 58%),
    radial-gradient(900px 600px at 80% 20%, rgba(139,92,255,.16), transparent 60%),
    radial-gradient(1200px 800px at 50% 100%, rgba(60,255,143,.10), transparent 62%),
    linear-gradient(180deg, var(--bg0), var(--bg1));
  overflow-x:hidden;
}

.page{min-height:100%; display:flex; flex-direction:column}
.topbar{
  padding:14px 16px 12px;
  display:flex;
  gap:12px;
  align-items:center;
  justify-content:space-between;
  position:sticky;
  top:0;
  z-index:20;
  background:
    radial-gradient(900px 520px at 20% -40%, rgba(45,242,255,.14), transparent 60%),
    radial-gradient(900px 520px at 80% -40%, rgba(139,92,255,.12), transparent 60%),
    linear-gradient(180deg, rgba(7,9,19,.92), rgba(7,9,19,.62));
  backdrop-filter:blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom:1px solid rgba(255,255,255,.10);
  box-shadow: 0 14px 60px rgba(0,0,0,.35);
}
.back{
  text-decoration:none;
  color:var(--text);
  display:flex;
  align-items:center;
  gap:10px;
  padding:10px 12px;
  border-radius:999px;
  background:rgba(255,255,255,.04);
  border:1px solid rgba(255,255,255,.10);
  box-shadow: 0 18px 70px rgba(0,0,0,.18);
  transition: transform .15s ease, border-color .15s ease, background .15s ease;
}
.back:hover{border-color:rgba(45,242,255,.28); background:rgba(45,242,255,.06); transform:translateY(-1px)}
.back:active{transform:translateY(1px)}
.back__chev{font-size:18px; opacity:.95}
.back__text{font-weight:750; letter-spacing:.2px}
.title{min-width:0}
.title__name{font-weight:900; letter-spacing:.2px; font-size:18px; line-height:1.1}
.title__sub{font-size:12px; color:var(--muted); margin-top:2px; white-space:nowrap; overflow:hidden; text-overflow:ellipsis; max-width:44vw}
.topbar__right{display:flex; gap:10px; align-items:center}

/* Header button polish (no content changes) */
.btn{
  border-radius:999px;
  border:1px solid rgba(255,255,255,.12);
  background:rgba(255,255,255,.04);
  box-shadow: 0 18px 70px rgba(0,0,0,.18);
  transition: transform .15s ease, border-color .15s ease, background .15s ease, box-shadow .15s ease;
}
.btn:hover{
  transform:translateY(-1px);
  border-color:rgba(139,92,255,.30);
  background:rgba(139,92,255,.08);
  box-shadow: 0 26px 90px rgba(0,0,0,.30);
}
.btn--primary:hover{border-color:rgba(45,242,255,.42)}

.main{padding:12px 14px 22px; width:min(1200px, 100%); margin:0 auto}
.hud{
  display:grid;
  grid-template-columns: repeat(4, minmax(0, 1fr)) auto;
  gap:10px;
  align-items:stretch;
  background:var(--panel);
  border:1px solid var(--border);
  border-radius:var(--radius);
  padding:10px;
  box-shadow:var(--shadow);
}
.hud__item{
  padding:10px 10px;
  border-radius:14px;
  background:rgba(255,255,255,.04);
  border:1px solid rgba(255,255,255,.06);
  min-width:0;
}
.hud__item--grow{grid-column:span 1}
.hud__label{font-size:11px; color:var(--muted); letter-spacing:.25px; text-transform:uppercase}
.hud__value{font-size:18px; font-weight:900; margin-top:4px}
.hud__actions{display:flex; gap:10px; align-items:stretch}

.btn{
  appearance:none;
  border:1px solid rgba(255,255,255,.10);
  background:linear-gradient(180deg, rgba(255,255,255,.10), rgba(255,255,255,.04));
  color:var(--text);
  padding:10px 12px;
  border-radius:14px;
  font-weight:850;
  letter-spacing:.2px;
  cursor:pointer;
  min-height:44px;
  touch-action:manipulation;
}
.btn:active{transform:translateY(1px)}
.btn--primary{
  border-color:rgba(45,242,255,.28);
  background:
    radial-gradient(120px 80px at 30% 20%, rgba(45,242,255,.26), transparent 55%),
    linear-gradient(180deg, rgba(45,242,255,.16), rgba(45,242,255,.06));
}
.btn--ghost{
  background:transparent;
  border:1px solid rgba(255,255,255,.10);
}
.btn--danger{
  border-color:rgba(255,61,113,.32);
  background:
    radial-gradient(120px 80px at 30% 20%, rgba(255,61,113,.22), transparent 55%),
    linear-gradient(180deg, rgba(255,61,113,.16), rgba(255,61,113,.06));
}

.play{
  margin-top:12px;
  display:grid;
  grid-template-columns: 1fr;
  gap:10px;
  align-items:start;
}
.stage{
  position:relative;
  border-radius:24px;
  overflow:hidden;
  background:
    radial-gradient(900px 500px at 50% 0%, rgba(45,242,255,.10), transparent 62%),
    radial-gradient(900px 500px at 50% 100%, rgba(139,92,255,.12), transparent 62%),
    linear-gradient(180deg, rgba(5,7,16,.92), rgba(12,14,28,.92));
  border:1px solid rgba(122,168,255,.20);
  box-shadow:var(--shadow);
  aspect-ratio: 1 / 1;
}
.stage--full{
  width:min(100%, 72vh);
  margin:0 auto;
}
canvas#game{
  width:100%;
  height:100%;
  display:block;
  touch-action:none;
}
.stage::after{
  content:"";
  position:absolute;
  inset:-2px;
  pointer-events:none;
  background:
    radial-gradient(250px 220px at 18% 14%, rgba(45,242,255,.14), transparent 62%),
    radial-gradient(280px 220px at 84% 18%, rgba(139,92,255,.14), transparent 60%),
    radial-gradient(280px 220px at 70% 92%, rgba(60,255,143,.10), transparent 62%);
  mix-blend-mode:screen;
  opacity:.9;
}

.stage__overlay{
  position:absolute;
  inset:0;
  display:flex;
  align-items:center;
  justify-content:center;
  padding:16px;
  background:rgba(4,6,14,.55);
  backdrop-filter: blur(10px);
}
.stage__overlay--hidden{display:none}
.card{
  width:min(520px, 100%);
  border-radius:22px;
  background:linear-gradient(180deg, rgba(18,22,44,.86), rgba(12,14,28,.78));
  border:1px solid rgba(122,168,255,.22);
  box-shadow:0 24px 70px rgba(0,0,0,.55);
  padding:18px;
}
.card__badge{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:6px 10px;
  border-radius:999px;
  border:1px solid rgba(45,242,255,.28);
  background:rgba(45,242,255,.10);
  color:rgba(233,240,255,.92);
  font-weight:900;
  font-size:12px;
  letter-spacing:.2px;
}
.card__badge--danger{
  border-color:rgba(255,61,113,.32);
  background:rgba(255,61,113,.12);
}
.card__title{margin:12px 0 8px; font-size:28px; line-height:1.1; font-weight:950; letter-spacing:.2px}
.card__text{margin:0 0 14px; color:var(--muted); font-size:14px; line-height:1.45}
.card__row{display:flex; gap:10px; flex-wrap:wrap}
.card__hint{margin-top:12px; font-size:12px; color:rgba(233,240,255,.66)}

.swipeHint{
  text-align:center;
  font-size:12px;
  color:rgba(233,240,255,.68);
  padding:8px 10px;
  border-radius:14px;
  background:rgba(255,255,255,.03);
  border:1px solid rgba(255,255,255,.06);
}

.modal{
  position:fixed;
  inset:0;
  z-index:20;
  display:flex;
  align-items:center;
  justify-content:center;
  padding:16px;
}
.modal--hidden{display:none}
.modal__backdrop{position:absolute; inset:0; background:rgba(0,0,0,.55)}
.modal__panel{
  position:relative;
  width:min(560px, 100%);
  border-radius:22px;
  background:linear-gradient(180deg, rgba(18,22,44,.92), rgba(10,12,26,.86));
  border:1px solid rgba(122,168,255,.22);
  box-shadow:0 26px 80px rgba(0,0,0,.6);
  overflow:hidden;
}
.modal__head{
  padding:14px 14px 10px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  border-bottom:1px solid rgba(255,255,255,.06);
}
.modal__title{font-weight:950; font-size:16px; letter-spacing:.2px}
.iconBtn{
  width:42px; height:42px;
  border-radius:14px;
  border:1px solid rgba(255,255,255,.10);
  background:rgba(255,255,255,.06);
  color:var(--text);
  cursor:pointer;
  font-weight:950;
  touch-action:manipulation;
}
.modal__body{padding:14px}
.field{margin-bottom:12px}
.field--row{display:flex; gap:10px; align-items:center; justify-content:flex-end; margin-top:6px}
.field__label{display:block; font-size:12px; color:rgba(233,240,255,.72); margin-bottom:6px; font-weight:850; letter-spacing:.18px}
.field__control{
  width:100%;
  min-height:44px;
  border-radius:14px;
  border:1px solid rgba(255,255,255,.10);
  background:rgba(255,255,255,.06);
  color:var(--text);
  padding:10px 12px;
  outline:none;
}
.note{font-size:12px; color:rgba(233,240,255,.64); margin-top:4px}
.how{margin:0; padding-left:18px; color:rgba(233,240,255,.78); line-height:1.55}
.how b{color:rgba(233,240,255,.96)}

.shake{animation:shake .22s linear 0s 2}
@keyframes shake{
  0%{transform:translate3d(0,0,0)}
  20%{transform:translate3d(-6px,0,0)}
  40%{transform:translate3d(6px,0,0)}
  60%{transform:translate3d(-4px,0,0)}
  80%{transform:translate3d(4px,0,0)}
  100%{transform:translate3d(0,0,0)}
}

@media (max-width: 900px){
  .title__sub{max-width:52vw}
}

@media (max-height: 760px){
  /* Short desktop windows: keep the square board fully visible */
  .stage--full{width:min(100%, 64vh)}
}
@media (max-width: 520px){
  .hud{grid-template-columns: repeat(2, minmax(0, 1fr)); grid-auto-rows:auto}
  .hud__actions{grid-column: 1 / -1; justify-content:space-between}
  .title__sub{display:none}
}