*{box-sizing:border-box;margin:0;padding:0}body{font-family:-apple-system,sans-serif;background:#f0f4ff}.app{display:flex;flex-direction:column;height:100vh;max-width:900px;margin:0 auto}header{display:flex;justify-content:space-between;align-items:center;padding:16px 24px;background:#1a4a7a;color:#fff}header h1{font-size:1.4rem}.status{font-size:.85rem;padding:4px 12px;border-radius:20px;background:#ffffff26}.status.online{color:#4ade80}.status.offline{color:#fbbf24}main{flex:1;overflow:hidden}.chat-container-with-sidebar{display:flex;height:100%}.chat-main{flex:1;display:flex;flex-direction:column}.chat-container{display:flex;flex-direction:column;height:100%}.sidebar-toggle{position:fixed;left:16px;top:80px;z-index:100;width:40px;height:40px;border-radius:50%;background:#1a4a7a;color:#fff;border:none;cursor:pointer;font-size:1.2rem;display:flex;align-items:center;justify-content:center;box-shadow:0 2px 8px #00000026}.chat-sidebar{width:280px;background:#fff;border-right:1px solid #e2e8f0;display:flex;flex-direction:column;padding:16px;overflow-y:auto}.sidebar-header{display:flex;flex-direction:column;gap:12px;margin-bottom:16px;padding-bottom:16px;border-bottom:1px solid #e2e8f0}.sidebar-header h3{font-size:1rem;color:#1a4a7a}.new-chat-btn{padding:10px 16px;background:#2563eb;color:#fff;border:none;border-radius:8px;cursor:pointer;font-weight:600;font-size:.9rem}.new-chat-btn:hover{background:#1d4ed8}.current-session{background:#f0f9ff;padding:12px;border-radius:8px;margin-bottom:16px}.session-title{font-weight:600;color:#1a4a7a;font-size:.9rem}.session-info{font-size:.75rem;color:#64748b;margin-top:4px}.sidebar-section{margin-bottom:16px}.section-toggle{width:100%;padding:10px 12px;background:#f8fafc;border:1px solid #e2e8f0;border-radius:8px;cursor:pointer;text-align:left;font-size:.9rem;color:#475569}.section-toggle:hover{background:#f1f5f9}.file-list{padding:8px 0}.file-list .empty{font-size:.8rem;color:#94a3b8;padding:8px 0}.file-item{padding:8px;border-radius:6px;margin-bottom:4px;font-size:.85rem;color:#475569;display:flex;align-items:center;gap:8px}.file-item:hover{background:#f1f5f9}.file-name{overflow:hidden;text-overflow:ellipsis;white-space:nowrap;flex:1}.upload-btn{display:block;width:100%;padding:10px;margin-top:8px;background:#f0f9ff;border:1px dashed #2563eb;border-radius:8px;text-align:center;color:#2563eb;cursor:pointer;font-size:.85rem}.upload-btn:hover{background:#e0f2fe}.messages{flex:1;overflow-y:auto;padding:24px;display:flex;flex-direction:column;gap:16px}.message{display:flex;flex-direction:column;max-width:80%}.message.user{align-self:flex-end;align-items:flex-end}.message.assistant{align-self:flex-start;align-items:flex-start}.bubble{padding:12px 16px;border-radius:16px;line-height:1.5;white-space:pre-wrap}.message.user .bubble{background:#2563eb;color:#fff;border-radius:16px 16px 4px}.message.assistant .bubble{background:#fff;border:1px solid #e2e8f0;border-radius:16px 16px 16px 4px}.message.loading .bubble{color:#94a3b8;font-style:italic}.sources{font-size:.75rem;color:#64748b;margin-top:4px}.input-area{display:flex;gap:8px;padding:16px 24px;background:#fff;border-top:1px solid #e2e8f0}.input-area input{flex:1;padding:10px 16px;border:1px solid #e2e8f0;border-radius:24px;font-size:.95rem;outline:none}.input-area input:focus{border-color:#2563eb}.input-area button{padding:10px 20px;background:#2563eb;color:#fff;border:none;border-radius:24px;cursor:pointer;font-weight:600}.input-area button:disabled{background:#94a3b8;cursor:not-allowed}