*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}

/* ── THEME: DARK GOLD (default) ── */
:root,[data-theme="dark-gold"]{
  --tb-h:48px;
  --lp-w:140px;
  --rp-w:280px;
  --sq:min(84px, calc((100vh - var(--tb-h) - 24px)/8), calc((100vw - var(--lp-w) - var(--rp-w) - 48px)/8));
  --bg:#0c0c10; --panel:#13131a; --border:#222230;
  --gold:#c9a84c; --gold2:#6e5c28; --gold3:rgba(201,168,76,.12);
  --tx:#ddd6c8; --dim:#8a8490;
  --ls:#efd9b2; --ds:#ae7b56;
  --accent:#c9a84c; --accent2:#6e5c28;
}

/* ── THEME: DARK BLUE ── */
[data-theme="dark-blue"]{
  --bg:#0f1623; --panel:#151d2e; --border:#1e2d44;
  --gold:#5b9bd5; --gold2:#2d4a6e; --gold3:rgba(91,155,213,.12);
  --tx:#c8d6e5; --dim:#6b7d94;
  --ls:#c5d1de; --ds:#5a7a9e;
  --accent:#5b9bd5; --accent2:#2d4a6e;
}

/* ── THEME: FOREST ── */
[data-theme="forest"]{
  --bg:#0a150c; --panel:#101e13; --border:#1a3320;
  --gold:#4caf60; --gold2:#2a5e34; --gold3:rgba(76,175,96,.12);
  --tx:#c8dccb; --dim:#6b8a70;
  --ls:#d4c9a8; --ds:#5e8a52;
  --accent:#4caf60; --accent2:#2a5e34;
}

/* ── THEME: CLASSIC (light) ── */
[data-theme="classic"]{
  --bg:#f0ece4; --panel:#faf8f4; --border:#d4cfc4;
  --gold:#8b6914; --gold2:#c4a44a; --gold3:rgba(139,105,20,.08);
  --tx:#2c2820; --dim:#8a8478;
  --ls:#f0d9b5; --ds:#b58863;
  --accent:#8b6914; --accent2:#c4a44a;
}

html,body{height:100%;overflow:hidden;background:var(--bg);color:var(--tx);
  font-family:'JetBrains Mono',monospace;overscroll-behavior:none}

/* ── TOPBAR ── */
#tb{height:var(--tb-h);display:flex;align-items:center;gap:10px;padding:0 14px;
  background:var(--panel);border-bottom:1px solid var(--border);flex-shrink:0}
#logo{font-family:'Playfair Display',serif;font-size:19px;color:var(--gold);
  letter-spacing:4px;text-transform:uppercase;flex-shrink:0;margin-right:4px;
  display:flex;align-items:center}
#logo-icon{height:28px;width:auto;margin-right:6px}

.seg{display:flex;background:var(--bg);border:1px solid var(--border);border-radius:5px;overflow:hidden}
.sbtn{padding:7px 14px;background:none;border:none;color:var(--dim);cursor:pointer;
  font:12px/1 'JetBrains Mono',monospace;transition:background .15s,color .15s}
.sbtn.on{background:var(--gold2);color:var(--gold)}
.sbtn:hover:not(.on){color:var(--tx)}

#rsec{display:none;align-items:center;gap:7px;padding:10px 14px;
  border-bottom:1px solid var(--border);flex-shrink:0}
#rinp{width:106px;padding:5px 9px;background:var(--bg);border:1px solid var(--border);
  border-radius:5px;color:var(--tx);font:12px/1 'JetBrains Mono',monospace;
  letter-spacing:2px;text-transform:uppercase}
#rinp::placeholder{letter-spacing:0;text-transform:none;color:var(--dim)}
#rinp:focus{outline:none;border-color:var(--gold2)}
#mycode{display:none;font-size:11px;color:var(--gold);letter-spacing:2px;
  padding:4px 9px;background:var(--gold3);border:1px solid var(--gold2);
  border-radius:5px;cursor:pointer}
#mycode:hover{background:rgba(201,168,76,.2)}

.btn{padding:7px 14px;background:none;border:1px solid var(--border);border-radius:5px;
  color:var(--tx);font:11px/1 'JetBrains Mono',monospace;cursor:pointer;
  transition:border-color .15s,color .15s,background .15s;white-space:nowrap;min-width:54px;text-align:center}
.btn:hover{border-color:var(--gold2);color:var(--gold);transform:translateY(-1px)}
.btn:active{transform:translateY(0)}
.btn.g{background:rgba(110,92,40,.7);border-color:var(--gold2);color:var(--gold)}
.btn.g:hover{background:rgba(110,92,40,.9)}

#stat{flex:1;text-align:right;font-size:12px;color:var(--dim);
  white-space:nowrap;overflow:hidden;text-overflow:ellipsis}

/* ── MAIN LAYOUT (two-sidebar) ── */
#main{height:calc(100vh - var(--tb-h));display:flex;min-height:0}

/* ── LEFT PANEL ── */
#lp{width:var(--lp-w);flex-shrink:0;background:var(--panel);
  border-right:1px solid var(--border);display:flex;flex-direction:column;min-height:0}

/* ── EVAL BAR (inside left panel) ── */
#ew{flex:1;display:flex;flex-direction:column;align-items:center;
  padding:8px 5px;gap:5px;transition:opacity .2s;min-height:0}
#ew.collapsed{opacity:.4;cursor:pointer}
#ew.collapsed #eb,#ew.collapsed #enum{display:none}
#eval-tog{font-size:13px;color:var(--dim);cursor:pointer;user-select:none;padding:6px 10px;
  margin-top:auto;border-radius:4px;transition:background .15s,color .15s}
#eval-tog:hover{color:var(--gold);background:var(--gold3)}
#eb{flex:1;width:26px;border-radius:9px;overflow:hidden;border:1px solid var(--border);
  display:flex;flex-direction:column;min-height:40px}
#ev-w{background:#e2dcd2;flex:.5;transition:flex .4s cubic-bezier(.4,0,.2,1)}
#ev-b{background:#10101a;flex:.5;transition:flex .4s cubic-bezier(.4,0,.2,1)}
#enum{font-size:10px;color:var(--dim);text-align:center;line-height:1.2;min-height:22px;
  display:flex;align-items:center;justify-content:center}

/* ── BOARD WRAP ── */
#bwrap{flex:1;display:flex;align-items:center;justify-content:center;
  background:var(--bg);padding:12px;min-width:0}
#board{display:grid;grid-template:repeat(8,var(--sq))/repeat(8,var(--sq));
  border:2px solid var(--border);border-radius:4px;
  box-shadow:0 8px 40px rgba(0,0,0,.6),0 0 0 1px rgba(255,255,255,.03);
  overflow:hidden;position:relative;touch-action:none}

.sq{width:var(--sq);height:var(--sq);position:relative;
  display:flex;align-items:center;justify-content:center;
  cursor:grab;user-select:none}
.sq.ls{background:var(--ls)}.sq.ds{background:var(--ds)}
.sq.sel{background:rgba(255,210,0,.45)!important}
.sq.lmv{background:rgba(205,210,106,.55)!important}
.sq.chk{background:radial-gradient(ellipse,rgba(210,35,35,.9) 0%,rgba(190,35,35,.25) 80%)!important;
  box-shadow:inset 0 0 0 3px rgba(210,35,35,.7)}
.sq.drag-over{background:rgba(255,210,0,.30)!important}

.dot,.cap{position:absolute;pointer-events:none;border-radius:50%;z-index:2;
  display:none}
.dot.show,.cap.show{display:block}
.dot{width:30%;height:30%;background:rgba(0,0,0,.22)}
.cap{inset:5%;border:6px solid rgba(0,0,0,.22);background:transparent;
  border-radius:50%;width:auto;height:auto}

.coord{position:absolute;font:10px 'JetBrains Mono',monospace;
  pointer-events:none;z-index:1;line-height:1}
.sq.ls .coord{color:rgba(170,130,90,.8)}.sq.ds .coord{color:rgba(240,217,181,.55)}
.coord.r{bottom:2px;right:3px}.coord.f{top:2px;left:3px}

/* ── ARROW LAYER ── */
#arrow-layer{position:absolute;top:0;left:0;
  width:calc(var(--sq)*8);height:calc(var(--sq)*8);
  pointer-events:none;z-index:5;overflow:visible}
#arrow-layer line{stroke-linecap:round}
#user-arrow-layer{position:absolute;top:0;left:0;
  width:calc(var(--sq)*8);height:calc(var(--sq)*8);
  pointer-events:none;z-index:3;overflow:visible}
#user-arrow-layer line{stroke-linecap:round}
.user-circle{position:absolute;border:4px solid rgba(235,97,52,0.85);border-radius:50%;
  pointer-events:none;z-index:3;width:calc(var(--sq) * 0.85);height:calc(var(--sq) * 0.85);
  top:calc(var(--sq) * 0.075);left:calc(var(--sq) * 0.075)}

/* ── ENGINE INFO ── */
#engine-info{display:none;padding:4px 8px;font-size:9px;color:var(--dim);
  text-align:center;line-height:1.4;word-break:break-all;max-height:48px;overflow:hidden}
#engine-info.on{display:block}

/* ── PIECE LAYER ── */
#piece-layer{position:absolute;top:0;left:0;
  width:calc(var(--sq)*8);height:calc(var(--sq)*8);
  pointer-events:none;z-index:4}
#piece-layer .pc{position:absolute;width:var(--sq);height:var(--sq);
  display:flex;align-items:center;justify-content:center;
  pointer-events:none;user-select:none;
  transition:top .15s ease-out, left .15s ease-out, opacity .15s ease-out}
#piece-layer .pc svg{width:100%;height:100%;pointer-events:none}
#piece-layer .pc.no-transition{transition:none}
#piece-layer.resizing .pc{transition:none!important}
#piece-layer .pc.dragging{z-index:100;transition:none;transform:scale(1.1);
  filter:drop-shadow(0 4px 8px rgba(0,0,0,.5))}
#piece-layer .pc.fade-out{opacity:0}

@media(hover:hover){
  .sq:hover{filter:brightness(1.08)}
}

/* ── RIGHT PANEL ── */
#rp{width:var(--rp-w);flex-shrink:0;background:var(--panel);
  border-left:1px solid var(--border);display:flex;flex-direction:column;min-height:0}

/* ── PLAYER STRIPS ── */
.ps{padding:10px 14px;border-bottom:1px solid var(--border);
  display:flex;align-items:center;gap:7px;flex-shrink:0;
  border-left:2px solid transparent;transition:border-color .2s, background .2s}
.ps.active-turn{border-left-color:var(--gold);border-left-width:3px;background:var(--gold3)}
.pd{width:12px;height:12px;border-radius:50%;border:1px solid rgba(255,255,255,.15);flex-shrink:0;
  transition:box-shadow .2s}
.ps.active-turn .pd{box-shadow:0 0 0 2px var(--gold)}
.pd.w{background:#e8e2d6}.pd.b{background:#12121a}
.pn{font-size:13px;font-weight:500;flex:1}
.pc2{display:flex;flex-wrap:wrap;gap:1px;align-items:center;min-height:14px}
.pc2 svg{width:14px;height:14px}

/* In left panel, player strips have no left border indicator — use bottom border instead */
#lp .ps{border-left:none;border-left-width:0}
#lp .ps.active-turn{border-left:none;background:var(--gold3);border-bottom-color:var(--gold)}

#hw{flex:1;overflow-y:auto;padding:8px;min-height:0;
  scrollbar-width:thin;scrollbar-color:var(--border) transparent}
#ht{width:100%;border-collapse:collapse;font-size:13px;
  font-variant-numeric:tabular-nums;line-height:1.6}
#ht td{padding:2px 4px;border-radius:3px}
#ht .nm{color:var(--dim);font-size:11px;width:26px}
#ht .mv{cursor:pointer;width:47%}
#ht .mv:hover{background:rgba(201,168,76,.15);color:var(--gold)}
#ht .mv.rv{background:rgba(201,168,76,.22);color:var(--gold)}
#ht .mv .mv-sym{font-size:9px;margin-left:2px;font-weight:700}
#ht .mv.blunder{color:#d44}
#ht .mv.mistake{color:#e8a030}
#ht .mv.inaccuracy{color:#cca030}
#ht .mv.good{color:#5a5}
#ht .mv.brilliant{color:#5ad}

/* ── NAVIGATION BUTTONS ── */
.nav-btn{padding:7px 12px;background:var(--gold2);border:1px solid var(--gold2);border-radius:5px;
  color:var(--gold);font:12px/1 'JetBrains Mono',monospace;cursor:pointer;
  transition:background .15s,color .15s,border-color .15s,opacity .15s;
  white-space:nowrap;min-width:36px;text-align:center;font-weight:500}
.nav-btn:hover:not(:disabled){background:rgba(110,92,40,.9);color:#fff}
.nav-btn:active:not(:disabled){transform:translateY(0)}
.nav-btn:disabled{opacity:.35;cursor:default;background:var(--border);border-color:var(--border);color:var(--dim)}
.nav-btn.nav-fwd{background:var(--gold2);color:var(--gold)}

#revbar{display:none;padding:8px 10px;background:var(--gold3);
  border-top:1px solid var(--gold2);font-size:10px;color:var(--gold);
  text-align:center;flex-shrink:0;flex-direction:column;align-items:center;gap:6px}
#revbar.on{display:flex}
#rev-nav{display:flex;gap:4px;justify-content:center}
#rev-nav .nav-btn{padding:5px 10px;font-size:14px;min-width:32px}
.rev-exit{color:var(--gold);font-size:10px}
#analysis-bar{display:none;padding:4px 10px;font-size:10px;color:var(--dim);
  text-align:center;flex-shrink:0}
#analysis-bar.on{display:block}
@keyframes analysis-pulse{0%,100%{opacity:.4}50%{opacity:1}}
#analysis-bar.on{animation:analysis-pulse 1.5s ease-in-out infinite}

#deprow{padding:8px 14px;border-bottom:1px solid var(--border);flex-shrink:0}
#deprow .seg{width:100%}
.aibtn{flex:1;padding:5px 2px;background:none;border:none;color:var(--dim);
  cursor:pointer;font-size:10px;transition:background .15s,color .15s}
.aibtn.on{background:var(--gold2);color:var(--gold)}
.aibtn:hover:not(.on){color:var(--tx)}
#ai-info{display:flex;justify-content:space-between;padding:4px 2px 0;font-size:9px;color:var(--dim)}

#ctrl{display:flex;flex-wrap:wrap;gap:6px;padding:10px 14px;
  border-top:1px solid var(--border);flex-shrink:0}
#ctrl .btn,#ctrl .nav-btn{flex:1 1 auto;min-width:0;padding:7px 8px;font-size:10px}

#rp-bottom{display:flex;align-items:center;justify-content:space-between;
  padding:6px 14px;border-top:1px solid var(--border);flex-shrink:0;margin-top:auto}

#sound-toggle{display:flex;align-items:center;gap:4px;font-size:10px;color:var(--dim);
  cursor:pointer;user-select:none;transition:color .15s}
#sound-toggle:hover{color:var(--tx)}
#sound-toggle .icon{font-size:13px;width:16px;text-align:center}

/* ── THEME PICKER ── */
#theme-picker{display:flex;gap:6px;align-items:center}
.theme-dot{width:18px;height:18px;border-radius:50%;border:2px solid var(--border);
  cursor:pointer;transition:border-color .15s,transform .15s;padding:0}
.theme-dot:hover{transform:scale(1.15)}
.theme-dot.active{border-color:var(--gold);box-shadow:0 0 0 2px var(--gold3)}
.theme-dot[data-theme="dark-gold"]{background:#c9a84c}
.theme-dot[data-theme="dark-blue"]{background:#5b9bd5}
.theme-dot[data-theme="forest"]{background:#4caf60}
.theme-dot[data-theme="classic"]{background:linear-gradient(135deg,#f0d9b5 50%,#b58863 50%)}

/* ── TIMERS ── */
.ptimer{margin-left:auto;font-size:13px;font-variant-numeric:tabular-nums;
  color:var(--dim);letter-spacing:1px;flex-shrink:0}
.ptimer.active{color:var(--gold)}
.ptimer.low{color:#d44;animation:pulse-timer 1s infinite}
@keyframes pulse-timer{0%,100%{opacity:1}50%{opacity:.5}}
#tc-row{padding:8px 14px;border-bottom:1px solid var(--border);flex-shrink:0}
#tc-row .seg{width:100%}
.tcbtn{flex:1;padding:5px 2px;background:none;border:none;color:var(--dim);
  cursor:pointer;font-size:10px;transition:background .15s,color .15s}
.tcbtn.on{background:var(--gold2);color:var(--gold)}
.tcbtn:hover:not(.on){color:var(--tx)}

/* ── DRAW OFFER ── */
#draw-bar{display:none;padding:8px 10px;background:var(--gold3);
  border-top:1px solid var(--gold2);font-size:11px;color:var(--gold);
  text-align:center;flex-shrink:0;gap:8px;align-items:center;justify-content:center}
#draw-bar.on{display:flex}
#draw-bar .btn{font-size:10px;padding:5px 10px;min-width:auto}

/* ── CHAT ── */
#chat-wrap{display:none;flex-direction:column;border-top:1px solid var(--border);
  max-height:240px;flex-shrink:0}
#chat-wrap.on{display:flex}
#chat-msgs{flex:1;overflow-y:auto;padding:6px 10px;font-size:12px;
  min-height:60px;max-height:160px;scrollbar-width:thin;scrollbar-color:var(--border) transparent}
.chat-msg{margin-bottom:4px;line-height:1.4}
.chat-msg .chat-who{font-weight:500;margin-right:4px}
.chat-msg .chat-who.w{color:#e8e2d6}.chat-msg .chat-who.b{color:#888}
#chat-input-row{display:flex;gap:4px;padding:4px 6px;border-top:1px solid var(--border)}
#chat-input{flex:1;padding:5px 8px;background:var(--bg);border:1px solid var(--border);
  border-radius:5px;color:var(--tx);font:12px/1 'JetBrains Mono',monospace}
#chat-input:focus{outline:none;border-color:var(--gold2)}
#chat-send{padding:5px 10px;background:var(--gold2);border:none;border-radius:5px;
  color:var(--gold);font:11px/1 'JetBrains Mono',monospace;cursor:pointer}
#chat-send:hover{background:rgba(110,92,40,.9)}
#chat-toggle{position:relative}
.chat-badge{position:absolute;top:-3px;right:-3px;width:8px;height:8px;
  background:#d44;border-radius:50%;display:none}
.chat-badge.on{display:block}

/* ── PREMOVE ── */
.sq.premove{background:rgba(70,130,220,.35)!important}

/* ── REVIEW COMMENTARY ── */
#review-comment{display:none;padding:5px 10px;font-size:10px;color:var(--tx);
  border-top:1px solid var(--border);flex-shrink:0;text-align:center;min-height:22px}
#review-comment.on{display:block}
#review-comment.blunder{color:#d44}
#review-comment.mistake{color:#e8a030}
#review-comment.inaccuracy{color:#cca030}
#review-comment.good{color:#5a5}
#review-comment.brilliant{color:#5ad}

/* ── MODALS ── */
.ov{position:fixed;inset:0;background:rgba(0,0,0,.68);
  display:flex;align-items:center;justify-content:center;
  z-index:50;backdrop-filter:blur(10px);opacity:0;transition:opacity .2s ease}
.ov.show{opacity:1}
.ov.off{display:none}
.mb{background:var(--panel);border:1px solid var(--border);border-radius:14px;
  padding:26px 22px;min-width:265px;box-shadow:0 28px 90px rgba(0,0,0,.85);
  transform:scale(.96);transition:transform .2s ease;position:relative}
.mcl{position:absolute;top:12px;right:14px;background:none;border:none;
  color:var(--dim);font-size:20px;cursor:pointer;line-height:1;padding:4px;transition:color .15s}
.mcl:hover{color:var(--tx)}
.ov.show .mb{transform:scale(1)}
.mt{font-family:'Playfair Display',serif;font-size:22px;color:var(--gold);
  text-align:center;margin-bottom:10px}
.ms{font-size:13px;color:var(--dim);text-align:center;margin-bottom:18px}
.mbtns{display:flex;gap:9px;justify-content:center;margin-top:16px}
.promos{display:flex;gap:10px;justify-content:center}
.psq{width:56px;height:56px;border:1px solid var(--border);border-radius:8px;
  display:flex;align-items:center;justify-content:center;
  background:var(--bg);cursor:pointer;transition:border-color .15s,background .15s}
.psq:hover{border-color:var(--gold);background:var(--gold3)}
.psq img{width:44px;height:44px}

/* ── TAKEBACK BAR ── */
#takeback-bar{display:none;padding:8px 10px;background:var(--gold3);
  border-top:1px solid var(--gold2);font-size:11px;color:var(--gold);
  text-align:center;flex-shrink:0;gap:8px;align-items:center;justify-content:center}
#takeback-bar.on{display:flex}
#takeback-bar .btn{font-size:10px;padding:5px 10px;min-width:auto}

/* ── OPENING NAME ── */
#opening-name{display:none;padding:4px 10px;font-size:10px;color:var(--dim);
  text-align:center;flex-shrink:0;border-bottom:1px solid var(--border);
  white-space:nowrap;overflow:hidden;text-overflow:ellipsis;
  transition:color .3s}
#opening-name.on{display:block}

/* ── TOAST ── */
#toast{position:fixed;bottom:max(18px, env(safe-area-inset-bottom));left:50%;
  transform:translateX(-50%) translateY(60px);
  background:var(--panel);border:1px solid var(--border);
  border-radius:8px;padding:8px 16px;font-size:12px;color:var(--tx);
  transition:transform .25s ease;z-index:200;pointer-events:none;white-space:nowrap;
  overflow:hidden}
#toast.on{transform:translateX(-50%) translateY(0)}
#toast.on::after{content:'';position:absolute;bottom:0;left:0;right:0;height:2px;
  background:var(--gold);animation:toast-shrink 2.6s linear forwards;transform-origin:left}
@keyframes toast-shrink{from{transform:scaleX(1)}to{transform:scaleX(0)}}

/* ── GAME HISTORY ── */
.hist-item{padding:10px 12px;border:1px solid var(--border);border-radius:6px;
  cursor:pointer;margin-bottom:6px;transition:border-color .15s,background .15s}
.hist-item:hover{border-color:var(--gold2);background:var(--gold3)}
.hist-top{display:flex;justify-content:space-between;align-items:center;gap:8px}
.hist-result{font-size:12px;font-weight:500;color:var(--gold)}
.hist-mode{font-size:10px;color:var(--dim);padding:2px 6px;background:var(--bg);border-radius:3px}
.hist-date{font-size:10px;color:var(--dim);margin-left:auto}
.hist-sub{font-size:10px;color:var(--dim);margin-top:4px}

/* ── ACCESSIBILITY ── */
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;
  overflow:hidden;clip-path:inset(50%);white-space:nowrap;border:0}

/* ── FOCUS INDICATORS ── */
.btn:focus-visible,.sbtn:focus-visible,.tcbtn:focus-visible,.aibtn:focus-visible,
.pzbtn:focus-visible,.psq:focus-visible,.mcl:focus-visible,#eval-tog:focus-visible,
#sound-toggle:focus-visible,#rp-toggle:focus-visible,.theme-dot:focus-visible,
.mob-btn:focus-visible,.nav-btn:focus-visible{
  outline:2px solid var(--gold);outline-offset:2px}

/* ── MOBILE ELEMENTS (hidden on desktop) ── */
#mob-toolbar,#mob-menu,#rp-toggle,.mob-player,#rp-handle,#rp-backdrop{display:none}

/* ── PUZZLE PANEL ── */
#puzzle-panel{padding:10px 14px;border-bottom:1px solid var(--border);flex-shrink:0;
  display:flex;flex-direction:column;gap:6px}
#pz-diff-bar{margin-bottom:4px}
.pzbtn{padding:6px 10px;background:none;border:none;color:var(--dim);cursor:pointer;
  font:10px/1 'JetBrains Mono',monospace;transition:background .15s,color .15s}
.pzbtn.on{background:var(--gold2);color:var(--gold)}
.pzbtn:hover:not(.on){color:var(--tx)}
#pz-header{display:flex;justify-content:space-between;align-items:center}
#pz-number{font-size:13px;font-weight:500;color:var(--gold)}
#pz-rating{font-size:11px;color:var(--dim);font-variant-numeric:tabular-nums}
#pz-theme{font-size:10px;color:var(--dim);text-transform:capitalize}
#pz-status{font-size:12px;text-align:center;padding:8px 0;color:var(--tx);
  min-height:36px;transition:color .2s}
#pz-status.correct{color:#5a5}
#pz-status.wrong{color:#d44}
#pz-status.hint{color:var(--gold)}
#pz-progress{display:flex;justify-content:space-between;font-size:10px;color:var(--dim);
  padding-top:6px;border-top:1px solid var(--border)}
.sq.pz-hint{background:rgba(201,168,76,.35)!important;
  animation:pz-hint-pulse 1s ease-in-out infinite}
@keyframes pz-hint-pulse{0%,100%{background:rgba(201,168,76,.25)}50%{background:rgba(201,168,76,.45)}}
.sq.pz-wrong{background:rgba(210,35,35,.45)!important}

/* ── MOBILE CHAT NOTIFICATION ── */
#mob-chat-btn.has-unread{color:var(--gold);border-color:var(--gold2);animation:chat-pulse 1.5s ease-in-out infinite}
@keyframes chat-pulse{0%,100%{background:transparent}50%{background:var(--gold3)}}

/* ── P2P STATUS ── */
.reconnecting{color:#e8a030!important;animation:reconnect-pulse 1s ease-in-out infinite}
@keyframes reconnect-pulse{0%,100%{opacity:.5}50%{opacity:1}}

/* ── DAILY PUZZLE ── */
#pz-daily-btn.completed{color:#5a5;border-color:#5a5;background:rgba(90,170,90,.12)}

/* ── LARGE DESKTOP ── */
@media(min-width:1440px){
  :root,[data-theme]{--lp-w:180px;--rp-w:320px;
    --sq:min(92px, calc((100vh - var(--tb-h) - 24px)/8), calc((100vw - var(--lp-w) - var(--rp-w) - 48px)/8))}
  #ht{font-size:14px}
  .ps{padding:12px 18px}
  .pn{font-size:14px}
  #ctrl .btn{padding:8px 10px}
  #chat-wrap{max-height:280px}
  #chat-msgs{max-height:200px}
}

/* ── EXTRA-LARGE DESKTOP ── */
@media(min-width:1920px){
  :root,[data-theme]{--lp-w:220px;--rp-w:380px;
    --sq:min(104px, calc((100vh - var(--tb-h) - 24px)/8), calc((100vw - var(--lp-w) - var(--rp-w) - 48px)/8))}
  .ps{padding:14px 20px}
  .pn{font-size:15px}
  .pc2 svg{width:16px;height:16px}
  .ptimer{font-size:14px}
  #ctrl .btn{padding:8px 12px;font-size:11px}
  .aibtn{font-size:11px}
  .tcbtn{font-size:11px}
}

/* ── ULTRA-WIDE DESKTOP ── */
@media(min-width:2560px){
  :root,[data-theme]{--tb-h:52px;--lp-w:240px;--rp-w:400px;
    --sq:min(120px, calc((100vh - var(--tb-h) - 24px)/8), calc((100vw - var(--lp-w) - var(--rp-w) - 48px)/8))}
  #tb{height:52px}
  #logo{font-size:21px}
  .sbtn{padding:8px 16px;font-size:13px}
  #ht{font-size:15px}
  .ps{padding:16px 22px}
  .pn{font-size:16px}
  .pc2 svg{width:18px;height:18px}
  .ptimer{font-size:16px}
  #ctrl .btn{padding:9px 14px;font-size:12px}
  .aibtn{font-size:12px;padding:6px 12px}
  .tcbtn{font-size:12px;padding:6px 12px}
  #chat-wrap{max-height:320px}
  #chat-msgs{max-height:240px;font-size:13px}
  #opening-name{font-size:11px}
}

/* ── MOBILE RESPONSIVE ── */
@media(max-width:768px){
  :root,[data-theme]{--sq:min(72px, calc((100vw - 16px)/8))}
  #logo{display:none}
  .sbtn{padding:6px 10px;font-size:10px}
  #main{flex-direction:column;align-items:center}

  /* Hide left panel on mobile */
  #lp{display:none}

  /* Show mobile player bars */
  .mob-player{display:flex;align-items:center;gap:7px;padding:6px 12px;
    background:var(--panel);border-bottom:1px solid var(--border);
    width:100%;flex-shrink:0;order:0}
  .mob-player .pd{width:10px;height:10px}
  .mob-player .pn{font-size:12px}
  .mob-player .pc2 svg{width:12px;height:12px}
  .mob-player .ptimer{font-size:12px}
  #mob-top{order:-2}
  #mob-bot{order:2}

  /* Board takes full width */
  #bwrap{padding:4px;flex:0 0 auto;order:0}
  #board{border-radius:4px}

  /* Right panel becomes bottom sheet */
  #rp{position:fixed;bottom:0;left:0;right:0;width:100%;height:65vh;
    z-index:30;border-left:none;border-top:1px solid var(--border);
    transform:translateY(100%);transition:transform .3s ease;
    border-radius:14px 14px 0 0;
    padding-bottom:env(safe-area-inset-bottom,0)}
  #rp.open{transform:translateY(0)}

  /* Bottom sheet drag handle */
  #rp-handle{display:flex;justify-content:center;padding:10px 0 6px;cursor:pointer}
  #rp-handle span{display:inline-block;width:40px;height:4px;background:var(--dim);
    border-radius:2px;opacity:.5}

  /* Bottom sheet backdrop */
  #rp-backdrop{display:block;position:fixed;inset:0;background:rgba(0,0,0,.4);
    z-index:29;transition:opacity .3s ease}
  #rp-backdrop.off{display:none}

  /* Show mobile toolbar */
  #mob-toolbar{display:flex;position:fixed;bottom:0;left:0;right:0;
    background:var(--panel);border-top:1px solid var(--border);
    padding:6px 10px;padding-bottom:max(6px, env(safe-area-inset-bottom));
    gap:6px;z-index:20;justify-content:center}
  .mob-btn{flex:1;min-height:44px;padding:8px 6px;background:none;border:1px solid var(--border);
    border-radius:6px;color:var(--tx);font:13px/1 'JetBrains Mono',monospace;
    cursor:pointer;text-align:center;max-width:100px;
    display:flex;align-items:center;justify-content:center;
    transition:border-color .15s,color .15s,transform .1s ease}
  .mob-btn:active{border-color:var(--gold);color:var(--gold);background:var(--gold3);
    transform:scale(.96)}
  .mob-btn.active{border-color:var(--gold);color:var(--gold);background:var(--gold3)}

  /* Mobile overflow menu */
  #mob-menu{display:block;position:fixed;bottom:56px;right:10px;z-index:25;
    background:var(--panel);border:1px solid var(--border);border-radius:8px;
    padding:4px;box-shadow:0 8px 30px rgba(0,0,0,.6)}
  #mob-menu.off{display:none}
  .mob-menu-item{display:block;width:100%;padding:12px 20px;background:none;border:none;
    color:var(--tx);font:13px/1 'JetBrains Mono',monospace;cursor:pointer;
    text-align:left;border-radius:4px;white-space:nowrap}
  .mob-menu-item:active{background:var(--gold3);color:var(--gold)}

  /* Hide desktop-only sidebar toggle */
  #rp-toggle{display:none}

  /* Adjust for mobile toolbar space */
  #main{height:calc(100vh - var(--tb-h))}

  #stat{font-size:10px}
  #tb{height:44px;padding:0 10px;gap:8px}
  .psq{width:68px;height:68px}
  .psq img,.psq svg{width:56px;height:56px}
  #puzzle-panel{padding:8px 10px}
  .pzbtn{padding:5px 8px;font-size:9px}
  .btn,.nav-btn{min-height:44px;display:flex;align-items:center;justify-content:center}
}

@media(max-width:480px){
  :root,[data-theme]{--sq:min(72px, calc((100vw - 8px)/8))}
  #bwrap{padding:2px}
  .sbtn{padding:5px 8px;font-size:10px}
  #tb{height:42px;padding:0 8px;gap:6px}
  #rsec{gap:5px;padding:8px 10px}
  #rinp{width:80px;font-size:11px}
}

/* ── LEARN/TUTORIAL PANEL ── */
#learn-panel{padding:10px 14px;border-bottom:1px solid var(--border);flex-shrink:0;
  display:flex;flex-direction:column;gap:8px;overflow-y:auto}
.lnbtn{padding:6px 10px;background:none;border:none;color:var(--dim);cursor:pointer;
  font:10px/1 'JetBrains Mono',monospace;transition:background .15s,color .15s}
.lnbtn.on{background:var(--gold2);color:var(--gold)}
.lnbtn:hover:not(.on){color:var(--tx)}
#learn-lesson-list{display:flex;flex-direction:column;gap:4px}
.learn-lesson-item{padding:10px 12px;border:1px solid var(--border);border-radius:6px;
  cursor:pointer;display:flex;align-items:flex-start;gap:10px;transition:border-color .15s,background .15s}
.learn-lesson-item:hover{border-color:var(--gold2);background:rgba(201,168,76,.05)}
.learn-lesson-item.completed{border-color:rgba(90,170,90,.4)}
.learn-check{font-size:16px;line-height:1;flex-shrink:0;margin-top:1px}
.learn-lesson-item.completed .learn-check{color:#5a5}
.learn-info{flex:1;min-width:0}
.learn-title{font-size:12px;font-weight:500;color:var(--tx)}
.learn-desc{font-size:10px;color:var(--dim);margin-top:2px}
#learn-active{display:flex;flex-direction:column;gap:6px}
#learn-title{font-size:14px;font-weight:500;color:var(--gold)}
#learn-step-count{font-size:10px;color:var(--dim)}
#learn-progress-bar{width:100%;height:4px;background:var(--border);border-radius:2px;overflow:hidden}
#learn-progress-fill{height:100%;background:var(--gold);border-radius:2px;transition:width .3s ease;width:0%}
#learn-status{font-size:12px;line-height:1.5;color:var(--tx);padding:6px 0;min-height:40px}
#learn-status.correct{color:#5a5}
#learn-status.wrong{color:#d44}
#learn-status.hint{color:var(--gold)}

/* ── MOBILE LANDSCAPE ── */
@media(max-width:768px) and (orientation:landscape){
  :root,[data-theme]{--sq:min(72px, calc((100vh - 54px)/8))}
  #main{flex-direction:row}
  #bwrap{padding:4px}
  #rp{height:100%;width:280px;bottom:0;top:0;left:auto;right:0;
    border-radius:0;border-top:none;border-left:1px solid var(--border);
    transform:translateX(100%);transition:transform .3s ease}
  #rp.open{transform:translateX(0)}
  #mob-toolbar{bottom:0}
  .mob-player{display:none}
}