:root{--bg: #0f1115;--panel: #171a21;--border: #262b36;--text: #e6e8ec;--muted: #8a93a3;--accent: #6c8cff;--user: #243049;--assistant: #1d2129}*{box-sizing:border-box}body{margin:0;font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;background:var(--bg);color:var(--text)}.app{display:flex;flex-direction:column;height:100vh}.topbar{display:flex;align-items:center;gap:12px;padding:12px 18px;border-bottom:1px solid var(--border);background:var(--panel)}.brand{font-weight:600}.spacer{flex:1}.user{color:var(--muted)}.logout{background:transparent;color:var(--muted);border:1px solid var(--border);border-radius:8px;padding:6px 12px;cursor:pointer}.logout:hover{color:var(--text)}.chat{flex:1;display:flex;flex-direction:column;max-width:820px;width:100%;margin:0 auto;padding:16px}.messages{flex:1;overflow-y:auto;display:flex;flex-direction:column;gap:10px;padding:8px}.empty{color:var(--muted);margin:auto}.bubble{max-width:80%;padding:10px 14px;border-radius:14px;line-height:1.45;white-space:pre-wrap}.bubble.user{align-self:flex-end;background:var(--user)}.bubble.assistant{align-self:flex-start;background:var(--assistant);border:1px solid var(--border)}.status{color:var(--accent);font-size:13px;padding:6px 10px;font-style:italic}.composer{display:flex;gap:10px;padding:10px;border-top:1px solid var(--border)}.composer textarea{flex:1;resize:none;height:56px;padding:10px 12px;border-radius:10px;border:1px solid var(--border);background:var(--panel);color:var(--text);font:inherit}.composer button{padding:0 20px;border:none;border-radius:10px;background:var(--accent);color:#fff;font-weight:600;cursor:pointer}.composer button:disabled{opacity:.5;cursor:default}