:root{--ink:#0A101E;--surface:#111a2c;--line:rgba(147,160,184,.18);--muted:#93A0B8;--text:#EAF0FA;--cyan:#19B8D4;--violet:#8B5CF6;--radius:14px;color-scheme:dark}
*{box-sizing:border-box}
body{margin:0;background:var(--ink);color:var(--text);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;display:flex;flex-direction:column;min-height:100vh}
.topbar{padding:28px 32px 8px}
.topbar h1{margin:0;font-size:26px;font-weight:700;letter-spacing:-.3px}
.accent{background:linear-gradient(135deg,var(--cyan),var(--violet));-webkit-background-clip:text;background-clip:text;color:transparent}
.tagline{color:var(--muted);margin:8px 0 0;font-size:14px;max-width:900px}

.layout{flex:1;display:grid;grid-template-columns:1fr 1fr;gap:18px;padding:16px 32px 8px;min-height:0}
.panel{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);display:flex;flex-direction:column;min-height:460px;overflow:hidden}
.panel-head{display:flex;align-items:center;justify-content:space-between;padding:12px 16px;border-bottom:1px solid var(--line);font-size:13px;color:var(--muted);font-weight:600}
.btns{display:flex;gap:8px}
.btn{font-family:inherit;font-size:12.5px;font-weight:600;padding:7px 14px;border-radius:8px;border:1px solid var(--line);cursor:pointer;background:transparent;color:var(--text);transition:border-color .15s,transform .15s}
.btn:hover{border-color:var(--cyan);transform:translateY(-1px)}
.btn-primary{background:linear-gradient(135deg,var(--cyan),var(--violet));border:none;color:#06121A}

#qaInput{flex:1;resize:none;border:none;outline:none;background:transparent;color:var(--text);font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:13px;line-height:1.7;padding:16px;white-space:pre}
.hint{margin:0;padding:8px 16px 12px;font-size:11.5px;color:var(--muted)}

.chat-log{flex:1;overflow:auto;padding:16px;display:flex;flex-direction:column;gap:10px}
.msg{max-width:82%;padding:9px 13px;border-radius:12px;font-size:13.5px;line-height:1.6}
.msg.user{align-self:flex-end;background:linear-gradient(135deg,var(--cyan),var(--violet));color:#06121A;border-bottom-right-radius:3px}
.msg.bot{align-self:flex-start;background:rgba(147,160,184,.1);border:1px solid var(--line);border-bottom-left-radius:3px}
.chat-form{display:flex;gap:8px;padding:12px;border-top:1px solid var(--line)}
.chat-form input{flex:1;background:rgba(147,160,184,.06);border:1px solid var(--line);border-radius:9px;padding:10px 12px;color:var(--text);font-family:inherit;font-size:13.5px;outline:none}
.chat-form input:focus{border-color:var(--cyan)}

.footer{padding:14px 32px 26px;color:var(--muted);font-size:12.5px;text-align:center}
.footer p{margin:4px 0}
.footer a{color:var(--cyan);text-decoration:none}
.footer a:hover{text-decoration:underline}

@media (max-width:860px){.layout{grid-template-columns:1fr}}