:root{
  --bg:#1a1208;--panel:#2a1f14;--text:#f5e6d3;--muted:#b8a090;
  --warn:#fbbf24;--red:#dc2626;--black:#1e293b;--wood:#8b5a2b;
  --touch:64px;
}
*{box-sizing:border-box;margin:0;padding:0;-webkit-tap-highlight-color:transparent}
body{
  min-height:100dvh;font-family:"PingFang TC","Noto Sans TC",system-ui,sans-serif;
  background:radial-gradient(ellipse at 30% 0%,#3d2914,transparent 55%),var(--bg);
  color:var(--text);
  padding:max(.5rem,env(safe-area-inset-top)) .7rem max(.5rem,env(safe-area-inset-bottom));
  user-select:none;
}
button{font:inherit;border:none;cursor:pointer;color:inherit}
button:active:not(:disabled){transform:scale(.98)}
button:disabled{opacity:.45}
.app{max-width:560px;margin:0 auto;min-height:calc(100dvh - 1rem);display:flex;flex-direction:column}
.screen{display:flex;flex-direction:column;gap:.55rem;flex:1;min-height:0}
.hidden{display:none!important}
.top{text-align:center}
.top h1{font-size:clamp(1.05rem,3.6vw,1.35rem);color:var(--warn);font-weight:900}
.gentle{color:var(--muted);font-weight:600;margin-top:.3rem}
.panel{
  background:var(--panel);border-radius:16px;padding:.9rem;
  border:1px solid rgba(251,191,36,.22);
}
.label{color:var(--warn);font-weight:800;margin:.4rem 0 .35rem}
.chips{display:flex;flex-wrap:wrap;gap:.4rem}
.chip,.chips button{
  min-height:var(--touch);padding:.45rem .75rem;border-radius:14px;
  background:rgba(0,0,0,.3);border:2px solid rgba(184,160,144,.3);font-weight:800;
}
.chip.active,.chips button.active{border-color:var(--warn);background:rgba(251,191,36,.18);color:var(--warn)}
.cur{font-weight:800;margin:.4rem 0}.cur span{color:var(--warn)}
.hint{color:var(--muted);font-weight:600;line-height:1.45;margin:.4rem 0}
.btn-go{
  width:100%;min-height:68px;margin-top:.55rem;border-radius:16px;font-weight:900;font-size:1.1rem;
  background:linear-gradient(180deg,#fcd34d,#d97706);color:#451a03;
}
.btn{
  min-height:52px;border-radius:14px;font-weight:800;padding:0 .8rem;
  background:rgba(255,255,255,.1);flex:1;
}
.btn.ghost{background:rgba(0,0,0,.25);width:100%;margin-top:.35rem}
.online-panel{margin-top:.5rem;padding-top:.4rem;border-top:1px dashed rgba(251,191,36,.25)}
.room-list{display:flex;flex-direction:column;gap:.4rem;margin:.35rem 0}
.room-btn{
  min-height:var(--touch);border-radius:14px;padding:.55rem .8rem;text-align:left;
  background:rgba(0,0,0,.28);border:2px solid rgba(251,191,36,.3);font-weight:800;
  display:flex;justify-content:space-between;gap:.4rem;flex-wrap:wrap;
}
.room-list .empty{text-align:center;color:var(--muted);font-weight:700;padding:.5rem}
.lobby-players{display:flex;flex-direction:column;gap:.4rem;margin:.5rem 0}
.lobby-players .lp{
  padding:.55rem .7rem;border-radius:12px;font-weight:800;
  background:rgba(0,0,0,.25);border:2px solid rgba(255,255,255,.1);
}
.lobby-players .lp.me{border-color:var(--warn);color:var(--warn)}
#lobby-code{color:var(--warn);letter-spacing:.1em}
.game-head{
  background:var(--panel);border-radius:14px;padding:.55rem .7rem;
  border:1px solid rgba(251,191,36,.2);
}
.game-head .row{display:flex;justify-content:space-between;font-weight:900;gap:.5rem;flex-wrap:wrap}
#turn-label{
  color:var(--warn);
  min-height:48px;
  padding:.28rem .75rem;
  border-radius:12px;
  display:inline-flex;
  align-items:center;
  font-weight:900;
  border:2px solid rgba(251,191,36,.5);
  background:rgba(251,191,36,.16);
}
html.elder-mode #turn-label{min-height:60px;font-size:1.15rem}
.toast{min-height:1.3em;text-align:center;color:#86efac;font-weight:800;margin-top:.25rem}
.room-tag{text-align:center;font-weight:700;color:var(--muted);font-size:.9rem}
.board-wrap{flex:1;min-height:0;
  background:
    repeating-linear-gradient(90deg,rgba(0,0,0,.14) 0 1px,transparent 1px 8px),
    repeating-linear-gradient(0deg,rgba(255,255,255,.06) 0 1px,transparent 1px 10px),
    linear-gradient(160deg,#8b5a2b,#3d2914);
  border-radius:16px;padding:.55rem;
  border:3px solid rgba(251,191,36,.35);
  box-shadow:inset 0 0 20px rgba(0,0,0,.35);
}
.board{
  display:grid;
  grid-template-columns:repeat(8,1fr);
  grid-template-rows:repeat(4,1fr);
  gap:.28rem;
  aspect-ratio:2/1;
}
.cell{
  border-radius:10px;
  background:rgba(0,0,0,.2);
  border:2px solid rgba(255,255,255,.08);
  display:flex;align-items:center;justify-content:center;
  min-height:0;position:relative;
  font-weight:900;
}
.cell.sel{box-shadow:0 0 0 3px var(--warn);z-index:1}
.cell.can{box-shadow:inset 0 0 0 4px #4ade80}
html.elder-mode .cell.can{box-shadow:inset 0 0 0 5px #86efac}
.piece{
  width:96%;height:96%;border-radius:50%;
  display:flex;align-items:center;justify-content:center;
  font-family:"Songti TC","Noto Serif TC","PingFang TC",serif;
  font-size:clamp(1.15rem,5.2vw,1.7rem);
  font-weight:900;
  letter-spacing:0;
  line-height:1;
  text-shadow:0 1px 0 rgba(255,255,255,.35),0 -1px 0 rgba(0,0,0,.25);
  box-shadow:0 5px 0 rgba(0,0,0,.48),0 8px 14px rgba(0,0,0,.32),inset 0 0 0 2px rgba(255,255,255,.22);
  border:3.5px solid rgba(255,255,255,.55);
  -webkit-font-smoothing:antialiased;
}
.piece.back{
  background:linear-gradient(160deg,#d97706,#7c2d12);
  color:transparent;
  text-shadow:none;
}
.piece.back::after{content:"暗";color:#fef3c7;font-size:.78em;font-weight:900;text-shadow:0 1px 2px rgba(0,0,0,.45)}
.piece.red{
  background:radial-gradient(circle at 32% 28%,#fff1f2 0%,#fecaca 42%,#b91c1c 100%);
  color:#7f1d1d;
  border-color:#fecaca;
  text-shadow:0 1px 0 rgba(255,255,255,.55),0 0 1px #7f1d1d;
}
.piece.black{
  background:radial-gradient(circle at 32% 28%,#f8fafc 0%,#cbd5e1 42%,#0f172a 100%);
  color:#020617;
  border-color:#e2e8f0;
  text-shadow:0 1px 0 rgba(255,255,255,.5),0 0 1px #020617;
}
html.elder-mode .piece{
  font-size:clamp(1.35rem,6vw,1.95rem);
  border-width:4px;
}
html.elder-mode .piece.red{color:#450a0a}
html.elder-mode .piece.black{color:#000}

.legend{
  display:flex;flex-wrap:wrap;gap:.4rem 1rem;justify-content:center;
  font-size:.8rem;font-weight:700;color:var(--muted);
}
.actions{display:flex;gap:.4rem;flex-shrink:0}
.overlay{
  position:fixed;inset:0;background:rgba(10,6,2,.8);
  display:flex;align-items:center;justify-content:center;padding:1rem;z-index:30;
}
.card{
  background:var(--panel);border-radius:18px;padding:1.1rem;width:min(420px,100%);
  border:2px solid rgba(251,191,36,.35);
}
.card h2{text-align:center;color:var(--warn);margin-bottom:.55rem}
.card ol{margin:.4rem 0 1rem 1.15rem;font-weight:700;line-height:1.6;color:#e7d5c0}