:root{--ink:#20242c;--muted:#7d828d;--line:#e4e6ea;--paper:#f6f7f8;--panel:#fff;--red:#ce3e45;--red-dark:#a82b32;--green:#1d6751;--gold:#d6a644;--board:#e9c98f;--board-line:#6f5133;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif}
*{box-sizing:border-box}html,body{margin:0;min-height:100%;color:var(--ink);background:var(--paper)}button,input,select{font:inherit}button{cursor:pointer}button:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid rgba(29,103,81,.22);outline-offset:2px}button:disabled{cursor:wait;opacity:.55}.hidden{display:none!important}.mobile-only{display:none!important}
.brand{display:flex;align-items:center;gap:10px;white-space:nowrap}.brand strong{font-size:19px}.brand-mark{display:grid;width:38px;height:38px;place-items:center;border-radius:8px;color:#fff;background:var(--green);box-shadow:0 7px 16px rgba(29,103,81,.2)}.brand-mark svg{width:22px;height:22px;stroke-width:2.5}
.auth-screen{display:grid;min-height:100vh;grid-template-columns:minmax(380px,.9fr) minmax(520px,1.3fr);background:#fff}.auth-panel{display:grid;align-content:center;width:min(430px,calc(100% - 48px));margin:auto;padding:36px 0}.auth-panel>.brand{margin-bottom:38px}.auth-copy h1{margin:0 0 8px;font-size:28px}.auth-copy p{margin:0 0 25px;color:var(--muted);font-size:14px}.auth-tabs{display:grid;grid-template-columns:1fr 1fr;margin-bottom:18px;border-bottom:1px solid var(--line)}.auth-tab{height:42px;border:0;border-bottom:2px solid transparent;color:var(--muted);background:transparent}.auth-tab.active{border-color:var(--green);color:var(--green);font-weight:700}.oauth-btn,.guest-btn,.primary-btn{display:flex;align-items:center;justify-content:center;gap:8px;height:45px;border-radius:7px;font-weight:700}.oauth-btn,.guest-btn{width:100%;border:1px solid #dfe1e6;background:#fff}.oauth-btn img{width:18px;height:18px}.guest-btn{margin-top:9px;color:#5f6570;background:#f8f9fa}.divider{display:flex;align-items:center;gap:12px;margin:18px 0;color:#a0a4ac;font-size:12px}.divider::before,.divider::after{height:1px;flex:1;content:"";background:var(--line)}.auth-form{display:grid;gap:12px}.auth-form label{display:grid;gap:6px;font-size:13px;font-weight:700}.auth-form input,.modal-card input{height:44px;padding:0 12px;border:1px solid #dfe1e6;border-radius:7px;background:#fff}.text-btn{justify-self:end;padding:0;border:0;color:var(--green);background:transparent;font-size:12px}.primary-btn{padding:0 17px;border:0;color:#fff;background:var(--green)}.auth-error{min-height:20px;margin:10px 0 0;color:var(--red);font-size:12px}.auth-error.success{color:var(--green)}
.auth-scene{position:relative;display:grid;place-items:center;overflow:hidden;color:#fff;background:#172b24}.auth-scene::before{position:absolute;inset:0;content:"";opacity:.2;background-image:linear-gradient(rgba(255,255,255,.16) 1px,transparent 1px),linear-gradient(90deg,rgba(255,255,255,.16) 1px,transparent 1px);background-size:54px 54px}.scene-board{position:relative;width:min(520px,72%);aspect-ratio:9/10;border:10px solid #b8864e;background:#d9b878;box-shadow:0 28px 70px rgba(0,0,0,.38);transform:rotate(-4deg)}.scene-board::before{position:absolute;inset:6%;content:"";background-image:linear-gradient(#795a37 1px,transparent 1px),linear-gradient(90deg,#795a37 1px,transparent 1px);background-size:12.5% 11.11%}.scene-river{position:absolute;top:45%;right:6%;left:6%;display:grid;height:10%;place-items:center;color:#5a4029;background:#d9b878;font:700 22px/1 KaiTi,"STKaiti",serif;letter-spacing:10px}.scene-piece{position:absolute;z-index:2;display:grid;width:17%;aspect-ratio:1;place-items:center;border:5px double currentColor;border-radius:50%;background:#f4dfb4;font:700 42px/1 KaiTi,"STKaiti",serif;box-shadow:0 10px 18px rgba(0,0,0,.28)}.scene-piece.red{right:15%;bottom:13%;color:var(--red)}.scene-piece.black{top:14%;left:18%;color:#24272c}.scene-copy{position:absolute;right:7%;bottom:6%;left:7%;z-index:2}.scene-copy strong{display:block;font-size:32px}.scene-copy span{display:block;margin-top:9px;color:rgba(255,255,255,.72)}
.app{min-height:100vh}.topbar{position:sticky;top:0;z-index:50;display:flex;align-items:center;height:68px;padding:0 24px;border-bottom:1px solid var(--line);background:rgba(255,255,255,.96);backdrop-filter:blur(12px)}.mode-tabs{display:flex;gap:5px;margin-left:48px}.mode-btn{display:flex;align-items:center;gap:7px;height:38px;padding:0 13px;border:0;border-radius:6px;color:#666c76;background:transparent}.mode-btn.active{color:#fff;background:var(--green)}.account-wrap{position:relative;margin-left:auto}.avatar{display:grid;width:38px;height:38px;place-items:center;overflow:hidden;border:0;border-radius:50%;color:#fff;background:var(--red);font-weight:800}.avatar img{width:100%;height:100%;object-fit:cover}.account-menu{position:absolute;top:46px;right:0;width:250px;padding:12px;border:1px solid var(--line);border-radius:7px;background:#fff;box-shadow:0 18px 45px rgba(30,34,42,.15)}.account-menu>div{overflow:hidden;font-size:13px;font-weight:700;text-overflow:ellipsis}.account-menu small{display:block;margin:5px 0 11px;color:var(--muted)}.rename-form{display:grid;grid-template-columns:1fr 38px;gap:6px;margin-bottom:9px}.rename-form input{min-width:0;height:38px;padding:0 9px;border:1px solid var(--line);border-radius:6px}.rename-form button{display:grid;height:38px;place-items:center;border:0;border-radius:6px;color:#fff;background:var(--green)}.account-menu>button{display:flex;align-items:center;gap:8px;width:100%;height:38px;padding:0 9px;border:0;border-radius:6px;color:var(--red);background:#fff2f3}
.game-layout{display:grid;grid-template-columns:minmax(520px,720px) minmax(300px,390px);gap:24px;justify-content:center;width:min(1160px,calc(100% - 36px));margin:auto;padding:22px 0 42px}.board-column{min-width:0}.player-row{display:grid;grid-template-columns:auto minmax(0,1fr) auto;align-items:center;gap:10px;min-height:64px;padding:4px 4px}.player-info{min-width:0}.player-avatar{display:grid;width:38px;height:38px;place-items:center;border:2px solid #3b3e44;border-radius:50%;color:#25272b;background:#ece9df;font-family:KaiTi,"STKaiti",serif;font-weight:800}.player-avatar.red{border-color:var(--red);color:var(--red)}.player-row strong{display:block;font-size:14px}.player-row small{display:block;margin-top:3px;color:var(--muted);font-size:11px}.captured-tray{display:flex;flex-wrap:wrap;align-items:center;gap:3px;min-height:25px;margin-top:5px}.captured-piece{display:grid;width:23px;height:23px;flex:0 0 auto;place-items:center;border:2px double currentColor;border-radius:50%;background:#f7e7c5;font:800 15px/1 KaiTi,"STKaiti",serif;box-shadow:0 1px 3px rgba(50,35,22,.2)}.captured-piece.red{color:var(--red-dark)}.captured-piece.black{color:#282b30}.clock{font:700 18px/1 ui-monospace,SFMono-Regular,Menlo,monospace}.board-shell{position:relative;width:min(100%,620px);margin:auto;padding:13px;border:1px solid #a47849;border-radius:7px;background:#c69256;box-shadow:0 15px 35px rgba(53,40,27,.2)}
.board{position:relative;display:grid;grid-template-columns:repeat(9,1fr);grid-template-rows:repeat(10,1fr);width:100%;aspect-ratio:9/10;overflow:hidden;border:2px solid var(--board-line);background:var(--board)}.board::after{position:absolute;z-index:0;top:45%;right:0;left:0;display:grid;height:10%;place-items:center;border-top:1px solid var(--board-line);border-bottom:1px solid var(--board-line);content:"楚 河　　汉 界";color:#785431;background:var(--board);font:700 clamp(18px,3vw,30px)/1 KaiTi,"STKaiti",serif;letter-spacing:6px}.point{position:relative;z-index:1;display:grid;min-width:0;min-height:0;place-items:center;padding:0;border:0;border-right:1px solid rgba(111,81,51,.72);border-bottom:1px solid rgba(111,81,51,.72);background:transparent}.point:nth-child(9n){border-right:0}.point:nth-child(n+82){border-bottom:0}.piece{position:relative;z-index:3;display:grid;width:76%;aspect-ratio:1;place-items:center;border:4px double currentColor;border-radius:50%;background:#f8e8c4;font:800 clamp(19px,3.2vw,34px)/1 KaiTi,"STKaiti",serif;box-shadow:0 3px 7px rgba(66,44,24,.3);transition:transform .15s}.point:hover .piece{transform:translateY(-2px)}.point.selected .piece{outline:4px solid rgba(29,103,81,.5);outline-offset:2px}.piece.red{color:var(--red-dark)}.piece.black{color:#26292e}.board.flipped{transform:rotate(180deg)}.board.flipped .piece{transform:rotate(180deg)}.board.flipped .point:hover .piece{transform:rotate(180deg) translateY(2px)}.thinking{position:absolute;inset:0;z-index:10;display:flex;align-items:center;justify-content:center;gap:9px;color:#fff;background:rgba(24,29,27,.56);font-weight:700}.thinking svg{animation:spin 1s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}
.game-toolbar{display:flex;align-items:center;justify-content:center;gap:8px;margin-top:12px}.icon-btn{display:grid;width:38px;height:38px;place-items:center;border:1px solid var(--line);border-radius:6px;color:#646a73;background:#fff}.icon-btn svg{width:18px}.command-btn{display:flex;align-items:center;gap:7px;height:38px;padding:0 14px;border:0;border-radius:6px;color:#fff;background:var(--red)}.game-toolbar select{height:38px;padding:0 28px 0 10px;border:1px solid var(--line);border-radius:6px;background:#fff}
.social-panel{min-height:620px;overflow:hidden;border:1px solid var(--line);border-radius:7px;background:#fff}.panel-head{display:flex;align-items:center;justify-content:space-between;padding:18px;border-bottom:1px solid var(--line)}.panel-head h2{margin:0 0 5px;font-size:17px}.panel-head p{margin:0;color:var(--muted);font-size:12px}.move-list{max-height:650px;overflow:auto;padding:12px}.move-row{display:grid;grid-template-columns:32px 1fr auto;gap:10px;align-items:center;min-height:44px;padding:7px 8px;border-bottom:1px solid var(--line);font-size:13px}.move-row span:first-child{color:var(--muted)}.empty-state{display:grid;min-height:180px;place-items:center;align-content:center;gap:10px;color:#a0a4ac;text-align:center;font-size:13px}.friend-tools{padding:14px}.my-code{display:flex;align-items:center;justify-content:space-between;margin-bottom:12px;color:var(--muted);font-size:12px}.my-code button{display:flex;align-items:center;gap:7px;border:0;color:var(--green);background:transparent}.add-friend{display:grid;grid-template-columns:1fr auto;gap:8px}.add-friend input{min-width:0;height:42px;padding:0 11px;border:1px solid var(--line);border-radius:7px;text-transform:uppercase}.panel-tabs{display:grid;grid-template-columns:repeat(3,1fr);margin:16px 0 8px;border-bottom:1px solid var(--line)}.panel-tab{height:38px;border:0;border-bottom:2px solid transparent;color:var(--muted);background:transparent}.panel-tab.active{border-color:var(--green);color:var(--green);font-weight:700}.social-list{display:grid;gap:7px;max-height:480px;overflow:auto}.social-item{display:grid;grid-template-columns:auto 1fr auto;gap:9px;align-items:center;min-height:55px;padding:8px;border:1px solid var(--line);border-radius:7px}.social-item .player-avatar{width:34px;height:34px}.social-item strong{display:block;overflow:hidden;font-size:13px;text-overflow:ellipsis}.social-item small{display:block;margin-top:3px;color:var(--muted);font-size:10px}.item-actions{display:flex;gap:5px}.mini-btn{display:grid;width:32px;height:32px;place-items:center;border:0;border-radius:6px;color:var(--green);background:#edf7f3}.mini-btn.accept{color:#fff;background:var(--green)}
.modal{position:fixed;inset:0;z-index:200;display:grid;place-items:center;padding:20px;background:rgba(18,21,25,.65);backdrop-filter:blur(7px)}.modal-card{width:min(420px,100%);padding:28px;border-radius:8px;background:#fff;box-shadow:0 25px 75px rgba(0,0,0,.28)}.modal-card h2{margin:18px 0 7px}.modal-card p{margin:0 0 18px;color:var(--muted);line-height:1.6}.modal-card form{display:grid;gap:10px}.result-card{text-align:center}.result-icon{display:grid;width:54px;height:54px;margin:auto;place-items:center;border-radius:50%;color:#fff;background:var(--red)}.result-card .primary-btn{width:100%;margin-top:10px}.toast{position:fixed;right:18px;bottom:18px;z-index:300;padding:11px 15px;border-radius:6px;color:#fff;background:#24282e;box-shadow:0 10px 28px rgba(0,0,0,.2);font-size:13px}
@media(max-width:900px){.auth-screen{grid-template-columns:1fr}.auth-scene{display:none}.game-layout{grid-template-columns:minmax(0,680px);width:min(100% - 20px,680px);padding-top:10px}.social-panel{position:fixed;z-index:80;inset:68px 0 0 auto;width:min(390px,92vw);min-height:0;border-radius:0;transform:translateX(105%);transition:transform .25s;box-shadow:-18px 0 45px rgba(30,34,40,.18)}.social-panel.open{transform:translateX(0)}.mobile-only{display:grid!important}.social-fab{position:fixed;z-index:70;right:14px;bottom:14px;grid-template-columns:auto auto;align-items:center;gap:7px;height:44px;padding:0 15px;border:0;border-radius:22px;color:#fff;background:var(--green);box-shadow:0 10px 25px rgba(29,103,81,.28)}.social-fab svg{width:18px}.mode-tabs{margin-left:24px}.board-shell{width:min(100%,590px)}}
@media(max-width:620px){.topbar{height:60px;padding:0 11px}.topbar .brand strong{display:none}.topbar .brand-mark{width:36px;height:36px}.mode-tabs{flex:1;justify-content:center;gap:2px;margin:0 5px}.mode-btn{height:36px;padding:0 9px}.mode-btn svg{display:none}.avatar{width:36px;height:36px}.game-layout{width:100%;padding:6px 0 70px}.player-row{padding-right:11px;padding-left:11px}.board-shell{width:100%;padding:7px;border-right:0;border-left:0;border-radius:0}.piece{width:82%;border-width:3px;font-size:clamp(18px,7vw,30px)}.game-toolbar{padding:0 8px;flex-wrap:wrap}.game-toolbar select{flex:1}.social-panel{top:60px}.auth-panel{width:calc(100% - 32px);padding:24px 0}.auth-panel>.brand{margin-bottom:28px}.auth-copy h1{font-size:25px}.oauth-btn,.guest-btn,.primary-btn{height:48px}.scene-copy{display:none}}