:root{--bg:#fbfbf9;--panel:#fff;--ink:#1c1c1a;--muted:#6b6b63;--line:#e2e2dc;--accent:#1f5f8b;--user:#eaf2f7;--history-w:264px}*{box-sizing:border-box}html,body,#root{height:100%}body{background:var(--bg);color:var(--ink);margin:0;font-family:Noto Sans Sinhala,Iskoola Pota,Nirmala UI,system-ui,sans-serif;font-size:16px;line-height:1.65}.app{grid-template-columns:var(--history-w) 1fr;height:100%;display:grid}.history{background:var(--panel);border-right:1px solid var(--line);padding:12px;overflow-y:auto}.history h2{text-transform:uppercase;letter-spacing:.06em;color:var(--muted);margin:8px 6px;font-size:12px}.session{text-align:left;width:100%;font:inherit;cursor:pointer;color:var(--ink);background:0 0;border:1px solid #0000;border-radius:8px;padding:8px 10px;font-size:14px;display:block}.session:hover{background:#f2f2ee}.session.active{border-color:var(--accent);background:var(--user)}.session .when{color:var(--muted);font-size:12px;display:block}.thread{flex-direction:column;min-height:0;display:flex}.thread header{border-bottom:1px solid var(--line);background:var(--panel);align-items:center;gap:10px;padding:10px 16px;display:flex}.thread header .title{font-weight:600}.thread header .note{color:var(--muted);font-size:12px}.messages{flex-direction:column;flex:1;gap:12px;padding:16px;display:flex;overflow-y:auto}.msg{max-width:68ch}.msg.user{background:var(--user);border:1px solid #d6e3ee;border-radius:10px;align-self:flex-end;padding:8px 12px}.msg.assistant{background:var(--panel);border:1px solid var(--line);border-radius:10px;align-self:flex-start;padding:8px 12px}.msg.part{margin:0 0 .6em}.msg.part:last-child{margin-bottom:0}.msg pre{background:#f4f4f0;border-radius:6px;padding:8px;font-size:13px;overflow-x:auto}.msg .tool{color:var(--muted);border-left:2px solid var(--line);white-space:pre-wrap;margin:6px 0;padding-left:8px;font-size:12px}.composer{border-top:1px solid var(--line);background:var(--panel);gap:8px;padding:12px 16px;display:flex}.composer textarea{resize:none;min-height:44px;max-height:160px;font:inherit;border:1px solid var(--line);color:var(--ink);background:#fff;border-radius:8px;flex:1;padding:10px}button.send,button.new{background:var(--accent);color:#fff;font:inherit;cursor:pointer;border:0;border-radius:8px;padding:0 16px}button.new{background:#557}button:disabled{opacity:.5;cursor:default}.drawer-toggle{border:1px solid var(--line);font:inherit;background:0 0;border-radius:8px;padding:4px 10px;display:none}@media (width<=760px){.app{grid-template-columns:1fr}.history{z-index:20;width:82vw;max-width:320px;transition:transform .18s;position:fixed;inset:0 auto 0 0;transform:translate(-100%);box-shadow:0 0 24px #0000002e}.history.open{transform:translate(0)}.drawer-toggle{display:block}.scrim{z-index:15;background:#0000004d;position:fixed;inset:0}}