*,*::before,*::after{box-sizing:border-box}
:root{
  --bg:#080a14;
  --bg2:#0e1222;
  --card:#141a2e;
  --line:#242c48;
  --ink:#eef1ff;
  --dim:#9aa3c7;
  --neon:#5de4ff;
  --pink:#ff6ad5;
  --lime:#9dff6a;
  --amber:#ffc24b;
  --r:18px;
  --mono:ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
}
html{scroll-behavior:smooth}
body{
  margin:0;background:var(--bg);color:var(--ink);
  font-family:system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  line-height:1.6;-webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
body.locked{overflow:hidden}
img{max-width:100%}
a{color:inherit}
.wrap{width:100%;max-width:1120px;margin:0 auto;padding:0 clamp(1rem,4vw,2rem)}
.skip{position:absolute;left:-999px;top:0;background:var(--neon);color:#001018;padding:.6rem 1rem;z-index:50}
.skip:focus{left:.5rem;top:.5rem;border-radius:8px}

/* header */
.top{position:sticky;top:0;z-index:20;backdrop-filter:blur(12px);
  background:color-mix(in srgb,var(--bg) 82%,transparent);border-bottom:1px solid var(--line)}
.top-in{display:flex;align-items:center;justify-content:space-between;gap:1rem;min-height:66px}
.brand{display:flex;align-items:center;gap:.55rem;font-weight:700;letter-spacing:-.02em;
  font-size:1.12rem;text-decoration:none}
.brand b{color:var(--neon);font-weight:800}
.brand-mark{color:var(--pink);font-size:1.35rem;line-height:1}
.top-nav{display:flex;gap:clamp(.7rem,2.5vw,1.6rem);font-size:.93rem;color:var(--dim)}
.top-nav a{text-decoration:none;padding:.3rem 0;border-bottom:1px solid transparent}
.top-nav a:hover,.top-nav a:focus-visible{color:var(--ink);border-color:var(--neon)}

/* hero */
.hero{position:relative;padding:clamp(3.2rem,9vw,6.5rem) 0 clamp(2.5rem,7vw,4.5rem);overflow:hidden}
.hero::before,.hero::after{content:"";position:absolute;border-radius:50%;filter:blur(90px);opacity:.33;pointer-events:none}
.hero::before{width:46vw;height:46vw;background:var(--neon);top:-14vw;right:-10vw}
.hero::after{width:38vw;height:38vw;background:var(--pink);bottom:-18vw;left:-12vw}
.hero-in{position:relative}
.eyebrow{margin:0 0 .9rem;font:600 .78rem/1 var(--mono);letter-spacing:.18em;text-transform:uppercase;color:var(--neon)}
h1{margin:0;font-size:clamp(2.3rem,7.4vw,4.5rem);line-height:1.03;letter-spacing:-.04em;font-weight:800}
.grad{background:linear-gradient(95deg,var(--neon),var(--pink) 60%,var(--amber));
  -webkit-background-clip:text;background-clip:text;color:transparent}
.lede{max-width:46ch;margin:1.3rem 0 0;color:var(--dim);font-size:clamp(1rem,2.2vw,1.14rem)}
.hero-cta{display:flex;flex-wrap:wrap;gap:.75rem;margin:1.9rem 0 0}
.btn{font:inherit;font-weight:650;border-radius:999px;border:1px solid transparent;
  padding:.78rem 1.5rem;cursor:pointer;text-decoration:none;display:inline-block;
  transition:transform .14s ease,background .18s ease,border-color .18s ease}
.btn:hover{transform:translateY(-2px)}
.btn:active{transform:translateY(0)}
.btn-main{background:linear-gradient(95deg,var(--neon),#8ff);color:#001620;
  box-shadow:0 10px 30px -12px var(--neon)}
.btn-ghost{background:transparent;border-color:var(--line);color:var(--ink)}
.btn-ghost:hover{border-color:var(--neon)}
.btn-small{padding:.48rem 1rem;font-size:.88rem;background:#1d2440;border-color:var(--line);color:var(--ink)}
.btn-small:hover{border-color:var(--neon)}
.btn-x:hover{border-color:var(--pink);color:var(--pink)}
.stats{display:flex;flex-wrap:wrap;gap:clamp(1.2rem,5vw,3rem);margin:2.6rem 0 0;padding:0}
.stats dt{font:600 .72rem/1 var(--mono);letter-spacing:.14em;text-transform:uppercase;color:var(--dim)}
.stats dd{margin:.35rem 0 0;font-size:1.5rem;font-weight:800;letter-spacing:-.02em}

/* sections */
.section{padding:clamp(2.6rem,7vw,4.6rem) 0}
.section-alt{background:var(--bg2);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.sec-title{margin:0;font-size:clamp(1.5rem,4vw,2.2rem);letter-spacing:-.03em}
.sec-sub{margin:.4rem 0 1.9rem;color:var(--dim)}

/* game grid */
.grid{list-style:none;margin:0;padding:0;display:grid;gap:clamp(.9rem,2.4vw,1.3rem);
  grid-template-columns:repeat(auto-fill,minmax(248px,1fr))}
.cab{position:relative;width:100%;text-align:left;background:var(--card);border:1px solid var(--line);
  border-radius:var(--r);padding:1.15rem;cursor:pointer;color:inherit;font:inherit;
  display:flex;flex-direction:column;gap:.5rem;overflow:hidden;
  transition:transform .16s ease,border-color .16s ease,box-shadow .16s ease}
.cab::after{content:"";position:absolute;inset:auto -30% -60% auto;width:160px;height:160px;
  border-radius:50%;background:var(--ac);filter:blur(46px);opacity:.22;transition:opacity .2s ease}
.cab:hover,.cab:focus-visible{transform:translateY(-4px);border-color:var(--ac);
  box-shadow:0 20px 40px -26px var(--ac);outline:none}
.cab:hover::after{opacity:.4}
.cab-emoji{font-size:2rem;line-height:1}
.cab h3{margin:0;font-size:1.16rem;letter-spacing:-.02em}
.cab p{margin:0;color:var(--dim);font-size:.92rem;position:relative}
.cab-foot{display:flex;align-items:center;justify-content:space-between;gap:.5rem;
  margin-top:.5rem;padding-top:.75rem;border-top:1px solid var(--line);position:relative}
.tag{font:600 .68rem/1 var(--mono);letter-spacing:.1em;text-transform:uppercase;color:var(--ac)}
.cab-best{font-size:.82rem;color:var(--dim)}
.play{font-size:.88rem;font-weight:650;color:var(--ac)}

/* scores */
.scores{list-style:none;margin:0 0 1.6rem;padding:0;display:grid;gap:.6rem;
  grid-template-columns:repeat(auto-fill,minmax(240px,1fr))}
.scores li{display:flex;align-items:center;justify-content:space-between;gap:1rem;
  background:var(--card);border:1px solid var(--line);border-radius:12px;padding:.8rem 1rem}
.scores span{display:flex;align-items:center;gap:.55rem;font-weight:600}
.scores b{font:800 1.05rem/1 var(--mono);color:var(--neon)}
.scores .none{color:var(--dim);font-weight:400}

/* about */
.about p{max-width:68ch;color:var(--dim)}
.about .note{border-left:3px solid var(--amber);padding-left:1rem;background:#12172a;
  border-radius:0 12px 12px 0;padding:.9rem 1rem}
.about .note b{color:var(--amber)}
kbd{font:600 .82em var(--mono);background:#1d2440;border:1px solid var(--line);
  border-radius:6px;padding:.1em .4em;color:var(--ink)}

/* footer */
.foot{border-top:1px solid var(--line);padding:1.6rem 0;color:var(--dim);font-size:.88rem}
.foot-in{display:flex;flex-wrap:wrap;gap:.6rem;justify-content:space-between}

/* game shell */
.shell{position:fixed;inset:0;z-index:40;background:rgba(4,6,14,.86);backdrop-filter:blur(8px);
  display:flex;align-items:center;justify-content:center;padding:clamp(.5rem,3vw,2rem)}
.shell[hidden]{display:none}
.shell-box{width:100%;max-width:720px;max-height:100%;overflow:auto;background:var(--bg2);
  border:1px solid var(--line);border-radius:var(--r);padding:clamp(.9rem,3vw,1.4rem);
  box-shadow:0 40px 90px -30px #000;animation:pop .18s ease}
@keyframes pop{from{opacity:0;transform:scale(.97) translateY(8px)}}
.shell-bar{display:flex;flex-wrap:wrap;align-items:center;gap:.8rem;justify-content:space-between;
  padding-bottom:.9rem;border-bottom:1px solid var(--line)}
.shell-head h3{margin:0;font-size:1.2rem;letter-spacing:-.02em}
.shell-head p{margin:.15rem 0 0;color:var(--dim);font-size:.84rem}
.shell-meta{display:flex;gap:.5rem}
.pill{background:#1a2039;border:1px solid var(--line);border-radius:10px;padding:.35rem .7rem;text-align:center;min-width:72px}
.pill span{display:block;font:600 .62rem/1.4 var(--mono);letter-spacing:.12em;text-transform:uppercase;color:var(--dim)}
.pill b{font:800 1.1rem/1.2 var(--mono);color:var(--neon)}
.shell-tools{display:flex;gap:.5rem}
.stage{display:flex;align-items:center;justify-content:center;padding:1rem 0 0;touch-action:manipulation}
.status{margin:.7rem 0 0;min-height:1.4em;text-align:center;color:var(--amber);font-size:.92rem;font-weight:600}

/* shared game bits */
canvas{max-width:100%;height:auto;background:#0a0d1a;border:1px solid var(--line);
  border-radius:12px;display:block;touch-action:none}
.board2048{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;background:#161c33;
  border:1px solid var(--line);padding:8px;border-radius:14px;width:min(100%,380px);touch-action:none}
.tile{aspect-ratio:1;border-radius:9px;background:#1d2440;display:grid;place-items:center;
  font:800 clamp(1rem,5vw,1.6rem)/1 var(--mono);color:#07101c;transition:background .12s ease}
.tile[data-v="0"]{color:transparent}
.memo{display:grid;grid-template-columns:repeat(4,1fr);gap:.55rem;width:min(100%,400px)}
.memo button{aspect-ratio:1;font-size:clamp(1.3rem,6vw,2rem);border-radius:12px;cursor:pointer;
  background:#1d2440;border:1px solid var(--line);color:transparent;transition:background .15s ease,transform .15s ease}
.memo button:hover:not(:disabled){transform:translateY(-2px);border-color:var(--neon)}
.memo button.up{background:#223055;color:var(--ink)}
.memo button.done{background:#19402c;border-color:var(--lime);color:var(--ink);cursor:default}
.react{position:relative;width:100%;height:min(58vh,360px);background:#0a0d1a;border:1px solid var(--line);
  border-radius:12px;overflow:hidden}
.dot{position:absolute;width:56px;height:56px;border-radius:50%;border:none;cursor:pointer;
  background:radial-gradient(circle at 34% 30%,#fff,var(--neon));box-shadow:0 0 22px var(--neon);
  transform:translate(-50%,-50%);animation:in .12s ease}
.dot.bad{background:radial-gradient(circle at 34% 30%,#fff,var(--pink));box-shadow:0 0 22px var(--pink)}
@keyframes in{from{transform:translate(-50%,-50%) scale(.4)}}
.hintpad{display:flex;gap:.5rem;justify-content:center;flex-wrap:wrap;margin-top:.8rem}
@media (max-width:520px){
  .top-nav a:nth-child(3){display:none}
  .shell-box{padding:1rem .8rem}
  .pill{min-width:62px}
}
@media (prefers-reduced-motion:reduce){
  *{animation-duration:.01ms !important;transition-duration:.01ms !important}
  html{scroll-behavior:auto}
}