@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,600;9..144,700&family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

:root{
  --bg:#0E1116; --surface:#161B22; --surface-2:#1D232C; --border:#2A313C;
  --text:#EAEDF1; --muted:#9AA3AE; --faint:#5B6470;
  --gold:#D9A94F; --gold-soft:#F0D9A8; --green:#4FBE85; --red:#E5646B;
  --serif:'Fraunces',ui-serif,Georgia,serif; --sans:'Inter',ui-sans-serif,system-ui,sans-serif;
  --mono:'JetBrains Mono',ui-monospace,SFMono-Regular,monospace;
  color-scheme: dark light;
}
@media (prefers-color-scheme: light){
  :root{
    --bg:#FAF8F4; --surface:#FFFFFF; --surface-2:#F3EFE7; --border:#E4DFD3;
    --text:#1C1B18; --muted:#5B564C; --faint:#8B8477;
    --gold:#A9781F; --gold-soft:#7A5613; --green:#1F7A4F; --red:#B0323A;
  }
}

*{box-sizing:border-box;}
html,body{height:100%;}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--sans);display:flex;flex-direction:column;overflow:hidden;}

header{display:flex;align-items:center;gap:12px;padding:16px 20px;border-bottom:1px solid var(--border);background:var(--surface);flex-shrink:0;}
.avatar{width:38px;height:38px;border-radius:10px;background:linear-gradient(135deg,var(--gold),var(--gold-soft));display:flex;align-items:center;justify-content:center;font-family:var(--serif);font-weight:700;color:#1C1B18;font-size:17px;flex-shrink:0;}
h1{font-family:var(--serif);font-weight:700;font-size:17px;margin:0;letter-spacing:-.01em;}
.h-sub{font-family:var(--mono);font-size:11px;color:var(--faint);letter-spacing:.02em;margin-top:2px;}
.h-sub .dot{display:inline-block;width:6px;height:6px;border-radius:50%;background:var(--green);margin-right:6px;vertical-align:middle;}

#thread{flex:1;overflow-y:auto;padding:24px 16px 12px;display:flex;flex-direction:column;gap:18px;}
.msg{max-width:640px;width:100%;margin:0 auto;display:flex;gap:10px;}
.msg.user{flex-direction:row-reverse;}
.bubble-avatar{width:28px;height:28px;border-radius:8px;flex-shrink:0;margin-top:2px;display:flex;align-items:center;justify-content:center;font-family:var(--serif);font-weight:700;font-size:12px;}
.msg.assistant .bubble-avatar{background:var(--gold);color:#1C1B18;}
.msg.user .bubble-avatar{background:var(--surface-2);color:var(--muted);border:1px solid var(--border);}
.bubble{background:var(--surface);border:1px solid var(--border);border-radius:14px;padding:12px 15px;font-size:14.5px;line-height:1.55;white-space:pre-wrap;max-width:100%;}
.msg.user .bubble{background:var(--surface-2);}
.bubble.thinking{color:var(--faint);font-style:italic;}
.bubble.error{border-color:var(--red);}

.welcome{max-width:640px;margin:8px auto 4px;text-align:center;padding:0 16px;}
.welcome h2{font-family:var(--serif);font-size:22px;font-weight:600;margin:0 0 8px;text-wrap:balance;}
.welcome p{color:var(--muted);font-size:14px;margin:0 auto;max-width:46ch;}
.chips{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;margin-top:16px;}
.chip{font-family:var(--mono);font-size:12px;padding:7px 13px;border-radius:999px;border:1px solid var(--border);background:var(--surface);color:var(--muted);cursor:pointer;transition:border-color .15s;}
.chip:hover{border-color:var(--gold);}

form{flex-shrink:0;border-top:1px solid var(--border);background:var(--surface);padding:14px 16px calc(14px + env(safe-area-inset-bottom));}
.input-row{max-width:640px;margin:0 auto;display:flex;align-items:flex-end;gap:10px;background:var(--surface-2);border:1px solid var(--border);border-radius:14px;padding:8px 8px 8px 14px;}
textarea{flex:1;background:transparent;border:none;outline:none;resize:none;color:var(--text);font-family:var(--sans);font-size:14.5px;line-height:1.5;max-height:120px;padding:6px 0;}
textarea::placeholder{color:var(--faint);}
.imgbtn,.sendbtn{border:none;border-radius:9px;cursor:pointer;flex-shrink:0;display:flex;align-items:center;justify-content:center;}
.imgbtn{width:34px;height:34px;background:transparent;color:var(--faint);}
.imgbtn:hover{color:var(--gold);}
.imgbtn.has-img{color:var(--green);}
.sendbtn{width:34px;height:34px;background:var(--gold);color:#1C1B18;}
.sendbtn:disabled{opacity:.4;cursor:default;}
.foot-note{max-width:640px;margin:10px auto 0;font-family:var(--mono);font-size:10.5px;color:var(--faint);text-align:center;line-height:1.5;}

.banner{max-width:640px;margin:0 auto;padding:10px 14px;border-radius:10px;background:var(--surface-2);border:1px solid var(--border);color:var(--muted);font-size:13px;text-align:center;}
.img-preview{max-width:640px;margin:0 auto 8px;display:flex;align-items:center;gap:8px;font-family:var(--mono);font-size:11.5px;color:var(--muted);}
.img-preview img{width:32px;height:32px;object-fit:cover;border-radius:6px;border:1px solid var(--border);}
.img-preview button{background:none;border:none;color:var(--faint);cursor:pointer;font-size:11px;text-decoration:underline;}