:root{--bg:#1f1e1d;--panel:#262624;--panel2:#30302e;--line:#3a3936;--text:#ece9e2;--muted:#9a978f;--accent:#d97757;--accent2:#c6613f;--user:#2f2e2b;--err:#e5786d;--ok:#7fc29b;--code:#161615}
*{box-sizing:border-box}
html,body{height:100%;margin:0}
body{background:var(--bg);color:var(--text);font:15px/1.6 -apple-system,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;-webkit-text-size-adjust:100%}
a{color:var(--accent)}
button,input,select,textarea{font:inherit;color:inherit}
.muted{color:var(--muted)}
.btn{background:var(--panel2);border:1px solid var(--line);border-radius:10px;padding:8px 14px;cursor:pointer;color:var(--text);text-decoration:none;display:inline-block}
.btn:hover{background:#3a3936}
.btn.primary{background:var(--accent);border-color:var(--accent);color:#fff}
.btn.primary:hover{background:var(--accent2)}
.btn.danger{color:var(--err)}
.btn.sm{padding:4px 10px;font-size:13px;border-radius:8px}
.btn:disabled{opacity:.5;cursor:not-allowed}
input,select,textarea{background:var(--panel);border:1px solid var(--line);border-radius:10px;padding:9px 12px;width:100%;outline:none}
input:focus,select:focus,textarea:focus{border-color:var(--accent)}
label{display:block;margin:12px 0;font-size:13px;color:var(--muted)}
label input,label select{margin-top:5px;color:var(--text);font-size:15px}
/* auth */
body.auth{display:flex;align-items:center;justify-content:center;padding:16px}
.card{background:var(--panel);border:1px solid var(--line);border-radius:16px;padding:28px;width:100%;max-width:380px}
.card h1{margin:0 0 6px;font-size:22px;text-align:center}
.card .logo{text-align:center;font-size:34px;color:var(--accent)}
.card .btn{width:100%;margin-top:8px;padding:11px}
.alert{padding:10px 12px;border-radius:10px;margin:12px 0;font-size:14px}
.alert.err{background:#3b2523;color:var(--err)}
.alert.ok{background:#22332a;color:var(--ok)}
/* app layout */
.app{display:flex;height:100dvh}
.sidebar{width:280px;background:var(--panel);border-right:1px solid var(--line);display:flex;flex-direction:column;flex-shrink:0;transition:transform .2s}
.sb-top{padding:12px;display:flex;flex-direction:column;gap:8px}
.brand{font-weight:600;font-size:17px;padding:4px 4px 2px;display:flex;align-items:center;gap:8px}
.brand span{color:var(--accent)}
.sb-list{flex:1;overflow-y:auto;padding:4px 8px}
.sb-group{font-size:12px;color:var(--muted);padding:12px 8px 4px}
.conv{display:flex;align-items:center;border-radius:8px;padding:7px 8px;cursor:pointer;gap:6px}
.conv:hover,.conv.active{background:var(--panel2)}
.conv .t{flex:1;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;font-size:14px}
.conv .acts{display:none;gap:2px}
.conv:hover .acts,.conv.active .acts{display:flex}
.iconbtn{background:none;border:0;cursor:pointer;color:var(--muted);padding:2px 5px;border-radius:6px;font-size:14px}
.iconbtn:hover{color:var(--text);background:#44433f}
.sb-foot{border-top:1px solid var(--line);padding:10px 12px;font-size:13px;display:flex;justify-content:space-between;align-items:center;gap:8px}
.sb-foot .who{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.sb-foot a{color:var(--muted);text-decoration:none;margin-left:8px}
.sb-foot a:hover{color:var(--text)}
.main{flex:1;display:flex;flex-direction:column;min-width:0}
.topbar{display:flex;align-items:center;gap:10px;padding:10px 14px;border-bottom:1px solid var(--line)}
.topbar .title{flex:1;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;font-weight:500}
.topbar select{width:auto;padding:6px 10px;font-size:14px}
.menu-btn{display:none}
.scroll{flex:1;overflow-y:auto;scroll-behavior:smooth}
.thread{max-width:780px;margin:0 auto;padding:20px 16px 8px}
.empty{text-align:center;margin-top:16vh;color:var(--muted)}
.empty .big{font-size:40px;color:var(--accent)}
.empty h2{color:var(--text);font-weight:500;margin:8px 0}
.msg{margin:18px 0}
.msg.user .bubble{background:var(--user);border-radius:16px;padding:10px 14px;margin-left:auto;max-width:88%;width:fit-content;white-space:pre-wrap;word-break:break-word}
.msg.assistant .bubble{word-break:break-word}
.msg .meta{font-size:12px;color:var(--muted);margin-top:4px;display:flex;gap:10px;align-items:center}
.msg.user .meta{justify-content:flex-end}
.files{display:flex;flex-wrap:wrap;gap:8px;justify-content:flex-end;margin-bottom:6px}
.files img{max-width:220px;max-height:180px;border-radius:12px;border:1px solid var(--line);cursor:zoom-in;display:block}
.chip{display:inline-flex;align-items:center;gap:6px;background:var(--panel2);border:1px solid var(--line);border-radius:10px;padding:5px 10px;font-size:13px;text-decoration:none;color:var(--text);max-width:240px}
.chip .n{overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.chip .x{cursor:pointer;color:var(--muted)}
.chip .x:hover{color:var(--err)}
/* markdown */
.md>*:first-child{margin-top:0}
.md p{margin:.6em 0}
.md h1,.md h2,.md h3{margin:1.1em 0 .4em;line-height:1.3}
.md h1{font-size:1.4em}.md h2{font-size:1.2em}.md h3{font-size:1.05em}
.md ul,.md ol{padding-left:1.5em;margin:.5em 0}
.md li{margin:.2em 0}
.md blockquote{border-left:3px solid var(--line);margin:.6em 0;padding:.1em 1em;color:var(--muted)}
.md code{background:var(--code);padding:2px 6px;border-radius:6px;font:13px/1.5 ui-monospace,Consolas,Menlo,monospace}
.md pre{background:var(--code);border:1px solid var(--line);border-radius:12px;margin:.8em 0;overflow:hidden;position:relative}
.md pre code{display:block;padding:14px;overflow-x:auto;background:none;font-size:13px}
.md pre .cbar{display:flex;justify-content:space-between;align-items:center;padding:5px 12px;background:#22211f;border-bottom:1px solid var(--line);font-size:12px;color:var(--muted)}
.md table{border-collapse:collapse;margin:.8em 0;display:block;overflow-x:auto}
.md th,.md td{border:1px solid var(--line);padding:6px 10px}
.md th{background:var(--panel)}
.md img{max-width:100%}
.cursor::after{content:"▍";animation:blink 1s infinite;color:var(--accent)}
@keyframes blink{50%{opacity:0}}
.errline{color:var(--err);font-size:14px;margin-top:6px}
/* composer */
.composer-wrap{padding:8px 16px 14px}
.composer{max-width:780px;margin:0 auto;background:var(--panel);border:1px solid var(--line);border-radius:18px;padding:10px 12px}
.composer:focus-within{border-color:#5a5852}
.composer.drag{border-color:var(--accent);background:#2c2826}
.composer textarea{border:0;background:none;padding:4px 4px;resize:none;max-height:220px;min-height:26px;display:block}
.attach-row{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:8px}
.attach-row .thumb{width:54px;height:54px;border-radius:10px;object-fit:cover;border:1px solid var(--line)}
.attach-row .item{position:relative}
.attach-row .item .x{position:absolute;top:-6px;right:-6px;background:#000c;border-radius:50%;width:20px;height:20px;text-align:center;line-height:20px;cursor:pointer;font-size:12px}
.crow{display:flex;align-items:center;gap:8px;margin-top:4px}
.crow .sp{flex:1}
.send{background:var(--accent);border:0;color:#fff;width:36px;height:36px;border-radius:10px;cursor:pointer;font-size:18px}
.send:disabled{background:var(--panel2);color:var(--muted);cursor:not-allowed}
.send.stop{background:#55534e}
.hint{text-align:center;font-size:12px;color:var(--muted);margin-top:8px}
.lightbox{position:fixed;inset:0;background:#000d;display:none;align-items:center;justify-content:center;z-index:50;cursor:zoom-out}
.lightbox img{max-width:94vw;max-height:94vh;border-radius:8px}
.lightbox.on{display:flex}
.backdrop{display:none}
@media(max-width:800px){
  .sidebar{position:fixed;inset:0 auto 0 0;z-index:30;transform:translateX(-100%);width:300px;max-width:86vw}
  .sidebar.open{transform:none}
  .backdrop.on{display:block;position:fixed;inset:0;background:#0009;z-index:20}
  .menu-btn{display:inline-block}
  .conv .acts{display:flex}
}
/* admin */
.page{max-width:980px;margin:0 auto;padding:24px 16px}
.page h1{margin:0 0 4px}
.page h2{margin-top:32px;font-size:18px}
.tbl{width:100%;border-collapse:collapse;margin-top:10px;font-size:14px;display:block;overflow-x:auto}
.tbl th,.tbl td{border-bottom:1px solid var(--line);padding:8px 10px;text-align:left;white-space:nowrap}
.tbl th{color:var(--muted);font-weight:500}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(170px,1fr));gap:10px;align-items:end}
.inline{display:inline}
.inline input{width:120px;padding:4px 8px;font-size:13px}
.tag{font-size:12px;padding:2px 8px;border-radius:99px;background:var(--panel2)}
.tag.admin{background:#4a2f25;color:#f0a58a}
.tag.off{background:#3b2523;color:var(--err)}

/* thanh sử dụng */
.usage{border-top:1px solid var(--line);padding:10px 14px;display:flex;flex-direction:column;gap:9px}
.usage:empty{display:none}
.meter .row{display:flex;justify-content:space-between;font-size:12px;color:var(--muted);margin-bottom:4px;gap:8px}
.meter .row b{color:var(--text);font-weight:500}
.meter .bar{height:6px;border-radius:99px;background:var(--panel2);overflow:hidden}
.meter .fill{height:100%;border-radius:99px;background:var(--ok);transition:width .4s}
.meter.warn .fill{background:#e0b15a}
.meter.crit .fill{background:var(--err)}
.ctxbar{max-width:780px;margin:0 auto 6px;display:none}
.ctxbar.on{display:block}