/* chess.css */
:root{
  --bg:#07111f;
  --panel:#0d1726;
  --panel-soft:#111f34;
  --ink:#f8fafc;
  --muted:#a7b4c8;
  --accent:#38d5ff;
  --accent-2:#21f0c2;
  --white-sq:#eef4ff;
  --black-sq:#33506f;
  --sel:#facc15;
  --red:#fb7185;
  --green:#4ade80;
  --gap:12px;
}
*{box-sizing:border-box}
html,body{margin:0;background:linear-gradient(180deg,#04111f,#0b1728);color:var(--ink);font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;min-height:100vh}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
.chess-app{max-width:1080px;margin:0 auto;padding:10px;min-height:100vh}
.game-header{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:10px;flex-wrap:wrap;border-top:3px solid #0ea5a8;padding-top:10px}
.back-link{padding:8px 12px;border-radius:999px;background:var(--panel-soft);color:var(--ink);font-weight:800;font-size:14px}
.back-link:hover{background:#1f3350}
.eyebrow{margin:0;font-size:11px;text-transform:uppercase;letter-spacing:.1em;color:var(--muted);font-weight:800;text-align:center}
.game-header h1{margin:1px 0 0;font-size:clamp(1.35rem,4vw,2rem);line-height:1.05;text-align:center}
.connection{padding:5px 12px;border-radius:999px;font-size:12px;font-weight:900}
.connection.online{background:rgba(74,222,128,.18);color:var(--green)}
.connection.offline{background:rgba(248,113,113,.18);color:var(--red)}
.panel{background:linear-gradient(180deg,var(--panel-soft),var(--panel));border:1px solid rgba(255,255,255,.08);border-radius:18px;padding:14px;box-shadow:0 12px 32px rgba(0,0,0,.36)}
.lobby h2{margin:0 0 8px}
.lobby p{margin:0 0 16px;color:var(--muted);font-size:14px}
.room-form{display:flex;gap:8px;margin-bottom:12px}
#room-code{flex:1;padding:13px 16px;border-radius:12px;border:1px solid #36516f;background:#07111f;color:var(--ink);font-size:16px;text-transform:uppercase;letter-spacing:.1em}
#room-code:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 3px rgba(56,213,255,.22)}
button{padding:12px 18px;border-radius:12px;border:none;font-weight:900;cursor:pointer;transition:.15s}
button:disabled{opacity:.5;cursor:not-allowed}
#join-room{background:linear-gradient(135deg,var(--accent),var(--accent-2));color:#05223a}
#join-room:hover{filter:brightness(1.05)}
.secondary{background:#334155;color:var(--ink)}
.secondary:hover{background:#475569}
.danger{background:#fb7185;color:#4c0519}
.danger:hover{filter:brightness(1.05)}
.message{min-height:18px;font-size:13px;font-weight:800}
.game-layout{display:grid;grid-template-columns:minmax(0,1fr) 286px;gap:var(--gap);align-items:start}
.hidden{display:none!important}
.game-info{display:flex;flex-wrap:wrap;gap:10px;margin-bottom:10px;font-size:14px;color:var(--muted);font-weight:800;justify-content:center}
.game-info strong{color:var(--ink);font-weight:950}
.board-panel{min-width:0}
.chess-board{display:grid;grid-template-columns:repeat(8,minmax(0,1fr));grid-template-rows:repeat(8,minmax(0,1fr));aspect-ratio:1;width:min(100%,calc(100vh - 155px),680px);margin:0 auto;background:#06111f;border-radius:14px;overflow:hidden;box-shadow:inset 0 0 0 3px #0f2742,0 16px 44px rgba(0,0,0,.48)}
.square{position:relative;display:flex;align-items:center;justify-content:center;cursor:pointer;width:100%;height:100%;padding:0;margin:0;min-width:0;min-height:0;border:0;border-radius:0;background-clip:padding-box;appearance:none;-webkit-appearance:none;line-height:1}
.square.white{background:linear-gradient(145deg,#f9fbff,#dce8fb)}
.square.black{background:linear-gradient(145deg,#3c5d7f,#223955)}
.square.selected{box-shadow:inset 0 0 0 5px var(--sel);z-index:2}
.square.valid-move::after{content:"";width:36%;height:36%;border-radius:50%;background:rgba(34,211,238,.42);box-shadow:0 0 0 4px rgba(34,211,238,.18)}
.square .piece{font-family:"Arial Unicode MS","Noto Sans Symbols 2","Segoe UI Symbol",serif;font-size:clamp(2.2rem,8.3vw,4.55rem);line-height:.9;user-select:none;pointer-events:none;transition:transform .12s,filter .12s;text-rendering:geometricPrecision;font-weight:900}
.piece-white{color:#fdfdfd;text-shadow:0 1px 0 #fff,0 2px 4px rgba(0,0,0,.82),0 0 1px #fff}
.piece-black{color:#161616;text-shadow:0 1px 0 #000,0 2px 4px rgba(255,255,255,.28),0 0 1px #000;filter:drop-shadow(0 1px 0 rgba(255,255,255,.2))}
.square.white .piece{filter:drop-shadow(0 2px 1px rgba(255,255,255,.8)) drop-shadow(0 3px 3px rgba(3,7,18,.68))}
.square.black .piece{filter:drop-shadow(0 2px 1px rgba(255,255,255,.52)) drop-shadow(0 4px 4px rgba(0,0,0,.86))}
.square.selected .piece{transform:scale(1.12)}
#turn-label{font-size:1rem}
.game-sidebar h2{margin:0 0 10px;font-size:1.15rem}
#game-status{margin:0 0 8px;color:var(--muted);font-weight:800}
.game-sidebar button{width:100%;margin-bottom:8px}
.game-sidebar small{display:block;margin-top:12px;color:var(--muted);font-size:12px}
@media(max-width:860px){
  .chess-app{padding:8px}
  .game-header{gap:6px;margin-bottom:8px;padding-top:7px}
  .back-link{padding:7px 10px;font-size:13px}
  .connection{padding:4px 10px}
  .game-layout{grid-template-columns:1fr;gap:10px}
  .game-info{font-size:13px;gap:8px;margin-bottom:8px}
  .chess-board{width:min(100%,calc(100vh - 250px));border-radius:12px}
  .square .piece{font-size:clamp(2.1rem,10.5vw,3.55rem)}
  .panel{padding:12px;border-radius:16px}
}
@media(max-width:420px){
  .chess-app{padding:6px}
  .game-header h1{font-size:1.42rem}
  .eyebrow{font-size:10px}
  .game-info{font-size:12px;line-height:1.15}
  .chess-board{width:min(100%,calc(100vh - 235px))}
  .square .piece{font-size:clamp(2rem,11vw,3.25rem)}
}
@media(max-height:720px) and (max-width:860px){
  .game-header{margin-bottom:6px}
  .game-info{margin-bottom:6px}
  .chess-board{width:min(100%,calc(100vh - 210px))}
  .game-sidebar{padding:10px}
  .game-sidebar h2{font-size:1rem;margin-bottom:6px}
  .game-sidebar small{display:none}
}