:root{
  color-scheme: dark;
  --bg:#050510;
  --panel:rgba(10,10,28,.82);
  --panel-strong:rgba(16,16,44,.94);
  --line:rgba(255,255,255,.16);
  --pink:#ff45dd;
  --cyan:#66e7ff;
  --gold:#ffd166;
  --lime:#8cff9b;
  --text:#f8fbff;
  --muted:#b9c3d6;
  --dark-square:#27164c;
  --light-square:#f4d8f4;
}
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  min-height:100vh;
  font-family:Inter,system-ui,-apple-system,Segoe UI,sans-serif;
  background:radial-gradient(circle at top left,#27164c,transparent 34rem),linear-gradient(135deg,#050510,#14051f 52%,#050510);
  color:var(--text);
  overflow:hidden;
}
.scanlines{position:fixed;inset:0;pointer-events:none;opacity:.12;background:repeating-linear-gradient(0deg,rgba(255,255,255,.18) 0 1px,transparent 1px 4px);mix-blend-mode:screen;z-index:4}
.bg-orb{position:fixed;border-radius:999px;filter:blur(45px);opacity:.48;pointer-events:none}.orb-a{width:20rem;height:20rem;background:#ff45dd;left:-5rem;top:7rem}.orb-b{width:24rem;height:24rem;background:#00e5ff;right:-7rem;bottom:0}
a{color:inherit}.arcade-shell{height:100vh;width:100vw;padding:clamp(.6rem,1.4vw,1.2rem);display:grid;grid-template-rows:auto 1fr;gap:.75rem}.arcade-hud{display:grid;grid-template-columns:minmax(12rem,1fr) minmax(15rem,2fr) minmax(12rem,1fr);align-items:center;gap:.75rem;padding:.72rem .9rem;border:1px solid var(--line);border-radius:22px;background:rgba(7,7,22,.72);backdrop-filter:blur(16px);box-shadow:0 18px 60px rgba(0,0,0,.28)}.brand{display:flex;align-items:center;gap:.65rem;text-decoration:none;font-weight:950;letter-spacing:.03em;text-transform:uppercase}.brand-mark{display:grid;place-items:center;width:2.3rem;height:2.3rem;border-radius:12px;background:linear-gradient(135deg,var(--pink),#8b5cf6);box-shadow:0 0 30px rgba(255,69,221,.42)}.game-status{justify-self:center;width:100%;max-width:35rem;text-align:center;border:1px solid rgba(102,231,255,.35);border-radius:999px;padding:.62rem 1rem;background:rgba(102,231,255,.08);color:#ecfbff;font-weight:950;letter-spacing:.04em;text-transform:uppercase;box-shadow:0 0 28px rgba(102,231,255,.16)}.hud-links{display:flex;justify-content:flex-end;gap:.5rem;flex-wrap:wrap}.hud-links a,.ghost{color:#fef7ff;text-decoration:none;border:1px solid rgba(255,255,255,.18);border-radius:999px;padding:.52rem .8rem;background:rgba(255,255,255,.07);font-weight:850}.arcade-stage{min-height:0;display:grid;grid-template-columns:minmax(15rem,22rem) minmax(24rem,1fr) minmax(14rem,21rem);gap:.9rem}.control-panel{min-height:0;border:1px solid var(--line);border-radius:28px;background:linear-gradient(180deg,rgba(255,69,221,.12),rgba(102,231,255,.07)),var(--panel);box-shadow:0 26px 70px rgba(0,0,0,.32);padding:clamp(.9rem,1.4vw,1.25rem);overflow:auto}.panel-kicker{margin:0;color:var(--cyan);font-size:.75rem;letter-spacing:.14em;text-transform:uppercase;font-weight:950}.left-panel h1{margin:.25rem 0 .55rem;font-size:clamp(2.2rem,4.5vw,4.6rem);line-height:.86;text-transform:uppercase;text-shadow:0 0 28px rgba(255,69,221,.35)}.microcopy{margin:0 0 1rem;color:var(--muted);line-height:1.45}.mode-stack{display:grid;gap:.65rem;margin:1rem 0}.mode-card{width:100%;text-align:left;border:1px solid rgba(255,255,255,.14);border-radius:18px;background:rgba(255,255,255,.06);color:var(--text);padding:.8rem;cursor:pointer}.mode-card span{display:block;font-weight:950;font-size:1rem}.mode-card small{display:block;color:var(--muted);margin-top:.2rem}.mode-card.active{border-color:rgba(255,69,221,.78);box-shadow:0 0 0 3px rgba(255,69,221,.12),0 0 32px rgba(255,69,221,.18);background:linear-gradient(135deg,rgba(255,69,221,.22),rgba(102,231,255,.09))}.field-label{display:block;margin:.75rem 0 .35rem;color:var(--cyan);font-size:.74rem;letter-spacing:.1em;text-transform:uppercase;font-weight:950}select,button{font:inherit}select{width:100%;border:1px solid rgba(255,255,255,.16);border-radius:15px;background:#0c0c24;color:var(--text);padding:.78rem .8rem;font-weight:850}select:disabled{opacity:.42}.button-grid{display:grid;grid-template-columns:1fr 1fr;gap:.6rem;margin-top:1rem}.button-grid button{border:0;border-radius:16px;padding:.85rem .72rem;background:linear-gradient(135deg,var(--pink),#8b5cf6);color:#fff;font-weight:950;cursor:pointer;box-shadow:0 18px 38px rgba(255,69,221,.22)}.button-grid button:last-child{background:linear-gradient(135deg,#1bc7ff,#7958ff)}.board-arena{min-width:0;min-height:0;display:grid;grid-template-rows:auto minmax(0,1fr) auto;gap:.7rem;align-items:center;justify-items:center}.score-ribbon{width:min(100%,56rem);display:grid;grid-template-columns:repeat(3,1fr);gap:.55rem}.score-ribbon div{border:1px solid var(--line);border-radius:18px;background:rgba(10,10,28,.72);padding:.62rem .78rem;text-align:center}.score-ribbon span,.mini-panel span{display:block;color:var(--muted);font-size:.72rem;letter-spacing:.12em;text-transform:uppercase;font-weight:950}.score-ribbon strong{display:block;margin-top:.12rem;color:#fff;font-size:1rem}.board{width:min(78vh,calc(100vw - 39rem),58rem);height:min(78vh,calc(100vw - 39rem),58rem);min-width:24rem;min-height:24rem;display:grid;grid-template-columns:repeat(8,1fr);grid-template-rows:repeat(8,1fr);border:clamp(.45rem,1vw,.8rem) solid rgba(255,255,255,.16);border-radius:24px;overflow:hidden;box-shadow:0 34px 95px rgba(0,0,0,.48),0 0 70px rgba(255,69,221,.12)}.square{border:0;display:grid;place-items:center;font-size:clamp(1.95rem,6.2vh,5.1rem);line-height:1;cursor:pointer;text-shadow:0 3px 8px rgba(0,0,0,.45);position:relative}.square.light{background:linear-gradient(135deg,#ffe6ff,#dfc2ef)}.square.dark{background:linear-gradient(135deg,#2b1555,#121230)}.square.white-piece{color:#fff}.square.black-piece{color:#080812;text-shadow:0 1px 0 rgba(255,255,255,.3)}.square.selected{outline:4px solid var(--gold);outline-offset:-4px}.square.legal::after{content:'';width:30%;height:30%;border-radius:999px;background:rgba(140,255,155,.86);box-shadow:0 0 18px rgba(140,255,155,.9);position:absolute}.board-help{width:min(100%,56rem);border:1px solid rgba(255,255,255,.13);border-radius:999px;background:rgba(255,255,255,.06);color:var(--muted);font-weight:850;text-align:center;padding:.65rem .9rem}.mini-panel{border:1px solid rgba(255,255,255,.14);border-radius:20px;background:rgba(255,255,255,.06);padding:.85rem;margin-bottom:.72rem}.mini-panel strong{display:block;margin-top:.2rem;font-size:1.05rem}.mini-panel p{margin:.5rem 0 0;color:var(--muted);line-height:1.35}.callout{border-color:rgba(255,209,102,.36);box-shadow:0 0 28px rgba(255,209,102,.09)}.notation{height:calc(100% - 11rem);min-height:14rem;overflow:auto}.notation ol{margin:.55rem 0 0;padding-left:1.2rem;color:var(--text);font-weight:800;columns:1}.notation li{padding:.16rem 0;color:#ecf3ff}
@media (max-width:1100px){body{overflow:auto}.arcade-shell{height:auto;min-height:100vh}.arcade-hud{grid-template-columns:1fr}.game-status{justify-self:stretch}.hud-links{justify-content:flex-start}.arcade-stage{grid-template-columns:1fr}.board{width:min(92vw,78vh);height:min(92vw,78vh);min-width:0;min-height:0}.right-panel{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:.7rem}.right-panel .mini-panel{margin:0}.notation{grid-column:1/-1;height:14rem}.score-ribbon{grid-template-columns:1fr 1fr 1fr}}
@media (max-width:640px){.arcade-shell{padding:.5rem}.score-ribbon{grid-template-columns:1fr}.button-grid,.right-panel{grid-template-columns:1fr}.left-panel h1{font-size:2.35rem}.square{font-size:clamp(1.5rem,10vw,3rem)}}