:root{--bg: #0f1115;--panel: #171a21;--border: #2a2f3a;--text: #e6e8eb;--muted: #8b93a1;--accent: #ff7a00;--user: #1f6feb;--tool: #2d2a18}*{box-sizing:border-box}html,body,#root{height:100%;margin:0}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,sans-serif;background:var(--bg);color:var(--text)}.app{max-width:760px;margin:0 auto;height:100vh;display:flex;flex-direction:column}.header{padding:12px 16px;border-bottom:1px solid var(--border);display:flex;justify-content:space-between;align-items:center}.header h1{font-size:14px;margin:0;font-weight:600}.header .status{font-size:11px;color:var(--muted)}.header button{background:transparent;color:var(--muted);border:1px solid var(--border);padding:4px 10px;border-radius:6px;font-size:11px;cursor:pointer}.header button:hover{color:var(--text);border-color:var(--accent)}.messages{flex:1;overflow-y:auto;padding:16px;display:flex;flex-direction:column;gap:10px}.msg{max-width:85%;padding:10px 14px;border-radius:12px;line-height:1.45;font-size:14px;white-space:pre-wrap;word-wrap:break-word}.msg.user{align-self:flex-end;background:var(--user);color:#fff;border-bottom-right-radius:4px}.msg.assistant{align-self:flex-start;background:var(--panel);border:1px solid var(--border);border-bottom-left-radius:4px}.msg.tool{align-self:flex-start;background:var(--tool);border:1px solid #4a3f1a;font-family:ui-monospace,Menlo,monospace;font-size:11px;color:#d4b870;max-width:85%}.composer{padding:12px 16px;border-top:1px solid var(--border);display:flex;gap:8px}.composer textarea{flex:1;resize:none;background:var(--panel);color:var(--text);border:1px solid var(--border);border-radius:8px;padding:10px 12px;font-family:inherit;font-size:14px;outline:none;min-height:40px;max-height:120px}.composer textarea:focus{border-color:var(--accent)}.composer button{background:var(--accent);color:#fff;border:0;border-radius:8px;padding:0 18px;font-weight:600;cursor:pointer;font-size:14px}.composer button:disabled{opacity:.5;cursor:not-allowed}.empty{color:var(--muted);text-align:center;margin-top:30vh;font-size:13px}