:root{--brand:#2563eb;--bg:#f3f4f6;--bot:#fff;--user:#2563eb}*{box-sizing:border-box}html,body,#root{height:100%;margin:0}body{font-family:system-ui,-apple-system,Segoe UI,Roboto,sans-serif;background:var(--bg)}.chat{display:flex;flex-direction:column;height:100%}header{background:var(--brand);color:#fff;padding:12px 16px;font-weight:600}.log{flex:1;overflow-y:auto;padding:16px;display:flex;flex-direction:column;gap:8px}.msg{max-width:80%;padding:10px 14px;border-radius:14px;line-height:1.4;white-space:pre-wrap;word-wrap:break-word}.msg.bot{background:var(--bot);align-self:flex-start;border-bottom-left-radius:4px;box-shadow:0 1px 2px #00000014}.msg.user{background:var(--user);color:#fff;align-self:flex-end;border-bottom-right-radius:4px}.msg.err{background:#fee2e2;color:#991b1b}form{display:flex;gap:8px;padding:12px;background:#fff;border-top:1px solid #e5e7eb}input{flex:1;padding:10px 12px;border:1px solid #d1d5db;border-radius:8px;font-size:15px}button{background:var(--brand);color:#fff;border:0;border-radius:8px;padding:0 18px;font-size:15px;cursor:pointer}button:disabled,input:disabled{opacity:.6;cursor:not-allowed}