:root{
  --bg:#0b0c0e; --side:#121316; --panel:#1b1d21; --hover:#22252a;
  --line:#2a2e35; --fg:#e8eaed; --dim:#9aa0a6; --dim2:#6b7076;
  --accent:#8ab4f8; --accent2:#4285f4; --ok:#81c995; --err:#f28b82; --warn:#fdd663;
  --mono:'SF Mono',ui-monospace,Menlo,Consolas,monospace;
  --sidew:292px;
}
*{box-sizing:border-box}
html,body{margin:0;height:100%}
body{background:var(--bg);color:var(--fg);display:flex;overflow:hidden;
  font:15px/1.7 'Google Sans','Segoe UI',-apple-system,BlinkMacSystemFont,sans-serif;
  -webkit-font-smoothing:antialiased}
button{font:inherit;cursor:pointer;border:none;background:none;color:inherit}
input,textarea,select{font:inherit;color:var(--fg)}
a{color:var(--accent)}
::-webkit-scrollbar{width:8px;height:8px}
::-webkit-scrollbar-thumb{background:#33373e;border-radius:4px}
::-webkit-scrollbar-track{background:transparent}

/* ── sidebar ─────────────────────────────────────────── */
#side{width:var(--sidew);flex:none;background:var(--side);display:flex;
  flex-direction:column;height:100vh;transition:width .18s ease;overflow:hidden}
body.collapsed #side{width:72px}
#brand{display:flex;align-items:center;gap:12px;padding:16px 18px 10px}
#brand .logo{width:26px;height:26px;flex:none}
#brand b{font-size:20px;font-weight:500;letter-spacing:.2px;white-space:nowrap}
body.collapsed #brand b,body.collapsed .lbl,body.collapsed #secthead,
body.collapsed #recents{opacity:0;pointer-events:none}
#collapse{margin-left:auto;color:var(--dim);padding:6px;border-radius:8px}
#collapse:hover{background:var(--hover)}

.navitem{display:flex;align-items:center;gap:16px;padding:11px 16px;margin:2px 10px;
  border-radius:99px;color:var(--fg);cursor:pointer;white-space:nowrap;font-size:14.5px}
.navitem:hover{background:var(--hover)}
.navitem.pri{background:var(--panel)}
.navitem.pri:hover{background:var(--hover)}
.navitem svg{flex:none;width:20px;height:20px;stroke:currentColor;fill:none;
  stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}
#secthead{padding:18px 20px 6px;font-size:12.5px;color:var(--dim);letter-spacing:.2px}
#recents{flex:1;overflow-y:auto;padding:0 10px 8px}
.rec{display:flex;align-items:center;gap:8px;padding:9px 12px;border-radius:99px;
  cursor:pointer;font-size:14px;color:var(--fg)}
.rec:hover{background:var(--hover)}
.rec.on{background:var(--panel)}
.rec .t{flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.rec .x{opacity:0;color:var(--dim);font-size:15px;padding:0 2px}
.rec:hover .x{opacity:.85}
#side footer{padding:12px 14px;display:flex;align-items:center;gap:12px}
.avatar{width:34px;height:34px;border-radius:50%;background:var(--accent2);
  display:grid;place-items:center;font-size:14px;font-weight:600;color:#fff;flex:none}
#side footer .sp{flex:1}
#side footer button{color:var(--dim);padding:8px;border-radius:50%}
#side footer button:hover{background:var(--hover);color:var(--fg)}

/* ── main ────────────────────────────────────────────── */
#main{flex:1;display:flex;flex-direction:column;height:100vh;min-width:0;
  position:relative;
  /* the blue wash in the corner, as in the reference */
  background:
    radial-gradient(1100px 620px at 78% 118%, rgba(48,84,190,.30), transparent 62%),
    radial-gradient(760px 460px at 96% 96%, rgba(66,133,244,.16), transparent 68%),
    var(--bg);}
#topbar{display:flex;align-items:center;gap:10px;padding:14px 20px;flex:none}
#topbar .sp{flex:1}
#topbar button{color:var(--dim);padding:8px;border-radius:50%}
#topbar button:hover{background:var(--hover);color:var(--fg)}
#chattitle{font-size:14.5px;color:var(--dim);overflow:hidden;
  text-overflow:ellipsis;white-space:nowrap;max-width:46vw}

#thread{flex:1;overflow-y:auto;padding:0 0 10px}
#hero{height:100%;display:flex;flex-direction:column;align-items:center;
  justify-content:center;padding-bottom:6vh}
#hero h1{font-size:44px;line-height:1.2;font-weight:400;margin:0;text-align:center;
  background:linear-gradient(92deg,#8ab4f8,#c58af9 45%,#f28b82);
  -webkit-background-clip:text;background-clip:text;color:transparent}
#hero p{color:var(--dim);font-size:14.5px;margin:14px 0 0}

.wrap{max-width:820px;margin:0 auto;padding:10px 26px}
.msg{margin-bottom:28px}
.msg .who{display:flex;align-items:center;gap:10px;margin-bottom:8px;
  font-size:13px;color:var(--dim)}
.msg .who .avatar{width:26px;height:26px;font-size:11px}
.msg.bot .who .avatar{background:linear-gradient(135deg,#8ab4f8,#c58af9)}
.body{font-size:15.5px}
.body p{margin:0 0 12px} .body p:last-child{margin-bottom:0}
.body pre{background:#0e1013;border:1px solid var(--line);border-radius:12px;
  padding:14px 16px;overflow-x:auto;font-family:var(--mono);font-size:13px;margin:0 0 12px}
.body code{font-family:var(--mono);font-size:.9em;background:#16181c;
  padding:2px 6px;border-radius:5px}
.body pre code{background:none;padding:0}
.body ul,.body ol{margin:0 0 12px;padding-left:24px}
.body li{margin-bottom:5px}
.body table{border-collapse:collapse;font-size:14px;margin:0 0 12px;width:100%}
.body th,.body td{border:1px solid var(--line);padding:7px 10px;text-align:left}
.body th{background:#16181c}
.body blockquote{margin:0 0 12px;padding-left:14px;border-left:3px solid var(--line);
  color:var(--dim)}
.body img.att{max-width:280px;border-radius:12px;margin:0 8px 8px 0;border:1px solid var(--line)}
.body[dir="rtl"]{text-align:right}
.tools{display:flex;gap:2px;margin-top:8px;opacity:0;transition:.15s}
.msg:hover .tools{opacity:1}
.tools button{font-size:12.5px;padding:5px 11px;border-radius:99px;color:var(--dim)}
.tools button:hover{background:var(--hover);color:var(--fg)}
.mmeta{font-family:var(--mono);font-size:11.5px;color:var(--dim2);margin-top:7px}
.err{background:#2d1a1a;border:1px solid #4d2626;color:#f6aeaa;padding:11px 13px;
  border-radius:10px;font-size:14px;white-space:pre-wrap}
.cursor{display:inline-block;width:8px;height:17px;background:var(--accent);
  vertical-align:text-bottom;animation:bl .9s step-end infinite;border-radius:2px}
@keyframes bl{50%{opacity:0}}

/* ── composer ────────────────────────────────────────── */
#composer{flex:none;padding:6px 0 22px}
#cwrap{max-width:820px;margin:0 auto;padding:0 26px}
#atts{display:flex;gap:9px;flex-wrap:wrap;margin-bottom:10px}
.att{position:relative}
.att img{height:62px;border-radius:10px;border:1px solid var(--line);display:block}
.att button{position:absolute;top:-6px;right:-6px;width:20px;height:20px;
  border-radius:50%;background:var(--panel);border:1px solid var(--line);
  font-size:11px;line-height:1;color:var(--fg)}
#bar{display:flex;align-items:center;gap:10px;background:var(--panel);
  border:1px solid transparent;border-radius:30px;padding:8px 10px 8px 14px}
#bar:focus-within{border-color:#343a42}
#bar>button{color:var(--dim);padding:8px;border-radius:50%;flex:none}
#bar>button:hover{background:var(--hover);color:var(--fg)}
#bar svg{width:20px;height:20px;stroke:currentColor;fill:none;stroke-width:1.8;
  stroke-linecap:round;stroke-linejoin:round}
#ta{flex:1;border:none;background:none;resize:none;max-height:210px;
  padding:8px 2px;font-size:15.5px;line-height:1.6;outline:none}
#ta::placeholder{color:var(--dim)}
#modelpill{display:flex;align-items:center;gap:7px;padding:7px 13px;border-radius:99px;
  color:var(--fg);font-size:14px;cursor:pointer;white-space:nowrap}
#modelpill:hover{background:var(--hover)}
#modelpill .dot{width:8px;height:8px;border-radius:50%;background:var(--accent2)}
#modelpill .cv{color:var(--dim);font-size:11px}
#sendbtn{background:var(--accent);color:#0b0c0e}
#sendbtn:hover{filter:brightness(1.08);background:var(--accent)}
#hint{text-align:center;font-size:11.5px;color:var(--dim2);margin-top:12px}

/* ── menus / modal ───────────────────────────────────── */
.menu{position:absolute;background:var(--panel);border:1px solid var(--line);
  border-radius:14px;padding:6px;min-width:250px;z-index:70;
  box-shadow:0 12px 40px #000a;display:none}
.menu.open{display:block}
.menu .mi{display:flex;align-items:center;gap:10px;padding:10px 12px;
  border-radius:9px;cursor:pointer;font-size:14px}
.menu .mi:hover{background:var(--hover)}
.menu .mi.on{background:var(--hover)}
.menu .mi small{display:block;color:var(--dim2);font-size:11.5px}
#modal{position:fixed;inset:0;background:#000c;display:none;z-index:80;
  align-items:center;justify-content:center;padding:26px}
#modal.open{display:flex}
.sheet{background:var(--side);border:1px solid var(--line);border-radius:18px;
  width:100%;max-width:620px;max-height:82vh;display:flex;flex-direction:column}
.sheet header{padding:18px 22px;font-size:17px;display:flex;align-items:center;gap:10px}
.sheet .in{flex:1;overflow-y:auto;padding:4px 22px 18px}
.sheet footer{padding:14px 22px;display:flex;gap:10px;justify-content:flex-end}
.btn{padding:9px 18px;border-radius:99px;font-size:14px;background:var(--panel)}
.btn:hover{background:var(--hover)}
.btn.pri{background:var(--accent);color:#0b0c0e;font-weight:500}
.fld{width:100%;background:#0e1013;border:1px solid var(--line);border-radius:10px;
  padding:11px 13px;font-size:14.5px;outline:none}
.fld:focus{border-color:var(--accent)}
.memrow{display:flex;gap:12px;align-items:flex-start;padding:12px 0;
  border-bottom:1px solid var(--line);font-size:14px}
.memrow.off{opacity:.45}
#toast{position:fixed;bottom:26px;left:50%;transform:translateX(-50%);z-index:99;
  background:var(--panel);border:1px solid var(--line);border-radius:10px;
  padding:11px 20px;display:none;max-width:70vw;box-shadow:0 10px 34px #000a;font-size:14px}
#toast.show{display:block} #toast.bad{border-color:var(--err);color:#f6aeaa}

/* ── login ───────────────────────────────────────────── */
body.auth{display:grid;place-items:center;background:
  radial-gradient(900px 520px at 70% 110%, rgba(48,84,190,.28), transparent 62%), var(--bg)}
.card{width:100%;max-width:392px;padding:34px 32px;background:var(--side);
  border:1px solid var(--line);border-radius:20px;text-align:center}
.card h1{font-size:25px;font-weight:400;margin:14px 0 6px}
.card p{color:var(--dim);font-size:14px;margin:0 0 22px}
.card .fld{margin-bottom:12px;text-align:left}
.card .btn.pri{width:100%;padding:12px}
.card .msg{min-height:20px;font-size:13.5px;margin-top:12px;color:var(--err)}
@media(max-width:820px){ #side{position:fixed;z-index:50;box-shadow:0 0 40px #000a}
  body.collapsed #side{width:0} #hero h1{font-size:32px} }