:root{
  --bg:#171512; --bg2:#221f1a; --panel:#2b2722; --line:#3a352e;
  --txt:#ece7de; --dim:#9b9186;
  --lt:#e9d7b8; --dk:#a97b52;
  --sel:#f2c14e; --user:#4a9df5; --claude:#f5883b;
  --ok:#5cc98a; --bad:#e0574a;
  --sq: min(9.6vw, 74px);
}
*{box-sizing:border-box;margin:0;padding:0}
body{
  background:radial-gradient(1100px 700px at 50% -10%,#2c2721,#141210 70%);
  color:var(--txt); font:15px/1.5 "Noto Sans CJK SC","Source Han Sans SC",system-ui,-apple-system,"Segoe UI",sans-serif;
  min-height:100vh; display:flex; align-items:center; justify-content:center; padding:16px;
}
.screen{display:none; width:100%}
.screen.active{display:block}
button{font-family:inherit; cursor:pointer; border:none; border-radius:10px; transition:.16s}
button:active{transform:translateY(1px)}
.primary{background:linear-gradient(180deg,#d8a54a,#b9832f); color:#211a0d; font-weight:700; font-size:16px; padding:13px 30px; box-shadow:0 4px 14px rgba(200,150,60,.25)}
.primary:hover{filter:brightness(1.08)}
.ghost{background:#332e28; color:var(--txt); border:1px solid var(--line); padding:9px 16px; font-size:14px}
.ghost:hover{background:#3d372f}

/* ---------- 主界面 ---------- */
.menu-card{max-width:520px; margin:0 auto; text-align:center; background:linear-gradient(180deg,#272219,#1d1a15);
  border:1px solid var(--line); border-radius:20px; padding:38px 30px 30px; box-shadow:0 24px 60px rgba(0,0,0,.5)}
.menu-crown{font-size:58px; color:#d8a54a; line-height:1; margin-bottom:6px; text-shadow:0 3px 16px rgba(216,165,74,.4)}
.menu-card h1{font-size:29px; letter-spacing:5px; margin-bottom:6px}
.sub{color:var(--dim); margin-bottom:26px; font-size:14px}
.side-pick{display:grid; grid-template-columns:repeat(3,1fr); gap:11px; margin-bottom:26px}
.side-btn{background:#2c2720; border:2px solid var(--line); border-radius:14px; padding:16px 6px; color:var(--txt); display:flex; flex-direction:column; align-items:center; gap:5px}
.side-btn:hover{border-color:#584f43}
.side-btn.selected{border-color:var(--sel); background:#3a3121; box-shadow:0 0 0 3px rgba(242,193,78,.13)}
.side-btn .pc{font-size:32px; line-height:1}
.side-btn .pc.w{color:#fff; text-shadow:0 0 2px #000,0 0 3px #000}
.side-btn .pc.b{color:#1a1a1a; text-shadow:0 0 2px #999}
.side-btn .pc.rand{color:#d8a54a; font-size:27px}
.side-btn b{font-size:15px}
.side-btn i{font-style:normal; font-size:11.5px; color:var(--dim)}
.hint{color:#6f675d; font-size:12px; margin-top:18px; line-height:1.7}

/* ---------- 布局 ---------- */
.layout{display:flex; gap:22px; align-items:flex-start; justify-content:center; flex-wrap:wrap}
.board-area{display:flex; flex-direction:column; gap:9px}
.player-bar{display:flex; align-items:center; gap:9px; padding:0 4px; min-height:30px}
.avatar{width:27px; height:27px; border-radius:7px; display:grid; place-items:center; font-size:19px; background:#332e27; border:1px solid var(--line)}
.avatar.w{color:#fff; text-shadow:0 0 2px #000}
.avatar.b{color:#151515; text-shadow:0 0 2px #888}
.pname{font-weight:600; font-size:14.5px}
.pname.turn::after{content:"● 思考中"; color:var(--sel); font-size:11.5px; font-weight:400; margin-left:8px}
.captured{color:var(--dim); font-size:18px; letter-spacing:-2px; line-height:1}

.board-frame{display:grid; grid-template-columns:20px auto; grid-template-rows:auto 20px; gap:3px}
.ranks,.files{display:grid; color:var(--dim); font-size:11.5px}
.ranks{grid-template-rows:repeat(8,1fr); place-items:center}
.files{grid-column:2; grid-template-columns:repeat(8,1fr); place-items:center}
.board-wrap{position:relative; border-radius:6px; overflow:hidden; box-shadow:0 16px 44px rgba(0,0,0,.55)}
.board{display:grid; grid-template-columns:repeat(8,var(--sq)); grid-template-rows:repeat(8,var(--sq))}

.sq{position:relative; display:grid; place-items:center; user-select:none}
.sq.lt{background:var(--lt)} .sq.dk{background:var(--dk)}
.sq .p{font-size:calc(var(--sq)*.78); line-height:1; pointer-events:none; z-index:2}
.sq .p.w{color:#fff; text-shadow:0 1px 0 #555,0 0 2px #000,0 0 4px rgba(0,0,0,.5)}
.sq .p.b{color:#1e1c1a; text-shadow:0 1px 0 #000,0 0 3px rgba(255,255,255,.28)}
.sq.movable{cursor:pointer}
.sq.mfrom::after,.sq.mto::after{content:""; position:absolute; inset:0; z-index:1}
.sq.mfrom.u::after,.sq.mto.u::after{background:rgba(74,157,245,.34)}
.sq.mfrom.c::after,.sq.mto.c::after{background:rgba(245,136,59,.34)}
.sq.sel::after{content:""; position:absolute; inset:0; background:rgba(242,193,78,.45); z-index:1}
.sq.dot::before{content:""; position:absolute; width:30%; height:30%; border-radius:50%; background:rgba(20,20,20,.28); z-index:3}
.sq.dot.cap::before{width:88%; height:88%; border-radius:50%; background:none; border:5px solid rgba(20,20,20,.26)}
.sq.check{animation:checkPulse 1.05s ease-in-out infinite}
@keyframes checkPulse{0%,100%{box-shadow:inset 0 0 0 0 rgba(224,87,74,0)}50%{box-shadow:inset 0 0 26px 7px rgba(224,87,74,.85)}}
.sq.lastdrop{animation:drop .34s ease}
@keyframes drop{0%{transform:scale(1.16)}100%{transform:scale(1)}}

.arrows{position:absolute; inset:0; width:100%; height:100%; pointer-events:none; z-index:4}

/* ---------- 侧栏 ---------- */
.panel{width:266px; background:var(--panel); border:1px solid var(--line); border-radius:14px; padding:15px; display:flex; flex-direction:column; gap:12px}
.status{font-size:15px; font-weight:600; padding:11px; border-radius:9px; background:#221f1a; text-align:center; border-left:3px solid var(--line)}
.status.check{color:var(--bad); border-left-color:var(--bad)}
.status.yours{color:var(--ok); border-left-color:var(--ok)}
.status.wait{color:var(--sel); border-left-color:var(--sel)}
.legend{display:flex; gap:14px; font-size:11.5px; color:var(--dim); justify-content:center}
.legend i.sw{display:inline-block; width:16px; height:3px; border-radius:2px; margin-right:5px; vertical-align:middle}
.sw.user{background:var(--user)} .sw.claude{background:var(--claude)}
.moves-box{height:250px; overflow-y:auto; background:#221f1a; border-radius:9px; padding:5px}
.moves{width:100%; border-collapse:collapse; font-size:13.5px; font-family:ui-monospace,"DejaVu Sans Mono",monospace}
.moves td{padding:4px 7px}
.moves td.n{color:#6f675d; width:32px}
.moves td.mv{cursor:default}
.moves tr:nth-child(odd){background:rgba(255,255,255,.022)}
.moves .cur{color:var(--sel); font-weight:700}
.fen{font:10.5px/1.45 ui-monospace,monospace; color:#6f675d; word-break:break-all; background:#221f1a; padding:7px; border-radius:7px}
.actions{display:flex; gap:8px}
.actions button{flex:1}

/* ---------- 弹层 ---------- */
.mask{position:fixed; inset:0; background:rgba(8,7,6,.74); backdrop-filter:blur(3px); display:none; align-items:center; justify-content:center; z-index:50}
.mask.show{display:flex}
.promo-card,.over-card{background:linear-gradient(180deg,#2b261f,#201d18); border:1px solid var(--line); border-radius:17px; padding:26px 30px; text-align:center; box-shadow:0 24px 60px rgba(0,0,0,.6)}
.promo-card h3{font-size:16px; margin-bottom:16px; font-weight:600}
.promo-row{display:flex; gap:10px; margin-bottom:15px}
/* 收到邀请：只在屏幕正中弹一个小框。不做全屏遮罩 —— 全屏会把整个界面糊住，挡视线又打断操作 */
.invite-pop{position:fixed; top:50%; left:50%; transform:translate(-50%,-50%); z-index:55; display:none;
  width:min(330px,86vw); background:linear-gradient(180deg,#33291c,#241e16); border:1px solid rgba(242,193,78,.55);
  border-radius:14px; padding:18px 20px; text-align:center; box-shadow:0 18px 44px rgba(0,0,0,.62)}
.invite-pop.show{display:block}
.invite-pop h3{font-size:17px; font-weight:600; margin:0 0 7px; color:#f4e7cd}
.invite-pop .sub{margin:0; font-size:14px; line-height:1.55; color:#d9cfba}
.invite-err{margin:7px 0 0; font-size:14px; line-height:1.55; color:#f0a98f}
.invite-row{display:flex; gap:10px; justify-content:center; margin-top:16px}
.invite-row button{font-size:14px; padding:9px 16px}

/* 局面研究：开局前选哪一方由谁走 */
.study-box{background:rgba(92,201,138,.09); border:1px solid rgba(92,201,138,.32); border-radius:12px; padding:12px 14px; margin-bottom:14px; text-align:left}
.study-head{font-size:13px; color:var(--dim); margin-bottom:8px}
.study-row{display:flex; align-items:center; gap:10px; margin-bottom:8px; font-size:14px}
.study-row span{min-width:34px; color:#d9cfba}
.study-row select{flex:1; background:#241f18; color:#eadfc8; border:1px solid var(--line); border-radius:8px; padding:6px 8px; font-size:14px}
.study-tip{margin:6px 0 0; font-size:12.5px; line-height:1.5; color:var(--dim)}
/* 对局界面里的引擎提示条 */
.hint-box{background:rgba(92,201,138,.10); border:1px solid rgba(92,201,138,.34); border-radius:10px; padding:9px 11px; margin-bottom:10px}
.hint-toggle{display:inline-flex; align-items:center; gap:6px; font-size:13px; color:#d9cfba; margin-right:12px}
.hint-toggle select{background:#241f18; color:#eadfc8; border:1px solid var(--line); border-radius:6px; padding:2px 5px; font-size:13px}
.hint-text{margin-top:7px; font-size:13.5px; line-height:1.5; color:#8fdcae}
.hint-text.bad{color:#f0a98f}
/* 主界面上的「有对局进行中」提示：无座位的人默认留在主界面，不再被拽进别人的棋局 */
.live-box{background:rgba(242,193,78,.10); border:1px solid rgba(242,193,78,.35); border-radius:12px; padding:12px 14px; margin-bottom:14px; text-align:left}
.live-head{font-size:13px; color:var(--dim); margin-bottom:8px}
.promo-row button{width:62px; height:62px; font-size:38px; background:#e9d7b8; border-radius:11px; display:grid; place-items:center}
.promo-row button:hover{background:#f5e6cb; transform:translateY(-2px)}
.promo-row button.w{color:#fff; text-shadow:0 0 2px #000,0 0 3px #000}
.promo-row button.b{color:#1e1c1a; text-shadow:0 0 2px rgba(255,255,255,.4)}

.over-card{min-width:322px; animation:pop .42s cubic-bezier(.2,1.3,.4,1)}
@keyframes pop{0%{transform:scale(.72) translateY(22px); opacity:0}100%{transform:scale(1) translateY(0); opacity:1}}
.over-icon{font-size:60px; line-height:1; margin-bottom:8px}
.over-card h2{font-size:27px; letter-spacing:3px; margin-bottom:6px}
.over-card p{color:var(--dim); margin-bottom:15px; font-size:14px}
.over-card.win .over-icon{color:#f2c14e; text-shadow:0 0 26px rgba(242,193,78,.65); animation:spin 2.6s ease-in-out infinite}
@keyframes spin{0%,100%{transform:rotate(-9deg) scale(1)}50%{transform:rotate(9deg) scale(1.13)}}
.over-card.win h2{color:#f2c14e}
.over-card.lose{animation:pop .42s cubic-bezier(.2,1.3,.4,1), shake .5s .42s}
@keyframes shake{0%,100%{transform:translateX(0)}20%{transform:translateX(-11px)}40%{transform:translateX(9px)}60%{transform:translateX(-6px)}80%{transform:translateX(4px)}}
.over-card.lose .over-icon{color:#e0574a; filter:grayscale(.3)}
.over-card.lose h2{color:#e0574a}
.over-card.draw .over-icon{color:#9b9186}
.over-moves{font:11.5px/1.6 ui-monospace,monospace; color:#7d746a; max-width:330px; max-height:74px; overflow-y:auto; margin-bottom:17px; text-align:left; background:#1c1915; padding:8px; border-radius:7px}
.over-actions{display:flex; gap:10px; justify-content:center}

#fx{position:fixed; inset:0; pointer-events:none; z-index:60; display:none}
#fx.show{display:block}

@media(max-width:900px){ .layout{flex-direction:column; align-items:center} .panel{width:min(94vw,420px)} :root{--sq:min(10.6vw,64px)} }

/* 观战席 */
.watch-badge{display:none;background:#2f3a46;color:#8fc7f5;border:1px solid #3d5060;
  border-radius:9px;padding:8px;text-align:center;font-size:13px;font-weight:600}

/* 难度档位选择（主界面） */
.level-pick{margin:18px 0 4px;padding:14px 14px 10px;background:var(--bg2);
  border:1px solid var(--line);border-radius:12px;text-align:left}
.level-head{display:flex;justify-content:space-between;align-items:baseline;margin-bottom:8px}
.level-head label{font-weight:700;font-size:14px;color:var(--txt)}
.level-elo{font-size:13px;font-weight:700;color:var(--sel);font-variant-numeric:tabular-nums}
.level-pick input[type=range]{width:100%;accent-color:var(--sel);cursor:pointer;height:22px}
.level-scale{display:flex;justify-content:space-between;font-size:11px;color:var(--dim);
  margin-top:-2px;padding:0 2px}
.level-desc{margin-top:8px;font-size:12.5px;color:var(--dim);line-height:1.45;min-height:2.6em}

/* 主界面 / 观战席里的链接式按钮 */
.link-btn{display:block;margin-top:10px;padding:10px 14px;text-align:center;text-decoration:none;
  color:var(--dim);border:1px solid var(--line);border-radius:10px;font-size:14px}
.link-btn:hover{color:var(--txt);border-color:var(--dim)}
.watch-badge a{color:#cfe6fa}

/* 模式切换：对战引擎 / 真人对弈 */
.mode-pick{display:flex;gap:8px;margin:14px 0 10px}
.mode-btn{flex:1;display:flex;flex-direction:column;align-items:center;gap:2px;padding:10px 8px;
  background:var(--bg2);border:1px solid var(--line);border-radius:12px;color:var(--txt);cursor:pointer;font:inherit}
.mode-btn b{font-size:15px}
.mode-btn i{font-style:normal;font-size:12px;color:var(--dim)}
.mode-btn.selected{border-color:var(--sel);box-shadow:0 0 0 1px var(--sel) inset}
#joinBtn{width:100%}

/* 当前账号（右上角） */
.user-bar{position:fixed;top:10px;right:14px;z-index:60;font-size:13px;color:var(--dim);
  background:var(--bg2);border:1px solid var(--line);border-radius:999px;padding:5px 12px}
.user-bar b{color:var(--txt)}
.user-bar a{color:var(--dim)}
.user-bar a:hover{color:var(--txt)}

/* 登录 / 注册 */
.auth-tabs{display:flex;gap:8px;margin:14px 0 6px}
.auth-tab{flex:1;padding:9px 8px;background:var(--bg2);border:1px solid var(--line);border-radius:10px;
  color:var(--dim);cursor:pointer;font:inherit}
.auth-tab.selected{color:var(--txt);border-color:var(--sel);box-shadow:0 0 0 1px var(--sel) inset}
.auth-notice{min-height:1.2em;margin:4px 0;font-size:13px;color:var(--sel)}
.auth-row{display:flex;flex-direction:column;gap:4px;margin:8px 0;text-align:left;font-size:13px;color:var(--dim)}
.auth-row input{padding:10px 12px;background:var(--bg);border:1px solid var(--line);border-radius:10px;
  color:var(--txt);font:inherit;font-size:15px}
.auth-row input:focus{outline:none;border-color:var(--sel)}
.auth-err{min-height:1.2em;margin:6px 0;font-size:13px;color:var(--bad)}
#authSubmit{width:100%}

/* 在线账号 */
.online-box{margin:10px 0;padding:10px 12px;background:var(--bg2);border:1px solid var(--line);border-radius:12px;text-align:left}
.online-head{font-size:13px;font-weight:700;color:var(--txt);margin-bottom:6px}
.online-head span{font-weight:400;color:var(--ok)}
.online-list{display:flex;flex-wrap:wrap;gap:6px;min-height:1.4em}
.online-user{font-size:12.5px;padding:3px 9px;border-radius:999px;background:var(--panel);color:var(--txt)}
.online-user::before{content:"● ";color:var(--ok)}
.online-user.me{color:var(--dim)}
.online-tip{margin-top:6px;font-size:12px;color:var(--dim)}

/* 和棋提议 */
.draw-banner{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin:8px 0;padding:10px 12px;
  background:#2f3a2a;border:1px solid #4d6a3f;border-radius:10px;color:#d8f0c4;font-weight:600}
.draw-banner span{flex:1;min-width:6em}
.draw-banner button{padding:6px 12px}
.draw-info{margin:8px 0;padding:8px 12px;border-radius:10px;background:var(--bg2);border:1px dashed var(--line);
  color:var(--dim);font-size:13px;text-align:center}

/* 指名邀请：主界面在线列表里点名字选人 */
.online-user.pick{cursor:pointer; border:1px solid #57503f}
.online-user.pick:hover{background:#3d372f; border-color:var(--sel)}
.online-user.picked{background:#3a3121; color:var(--sel); font-weight:700; border:1px solid var(--sel)}
.invite-tip{font-size:11.5px; color:#8a8175; margin-top:7px; line-height:1.6}
.level-note{font-size:11px; color:#6f675d; line-height:1.7; margin-top:6px; text-align:left}
.level-note b{color:#8a8175}