:root{color-scheme:dark;font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;line-height:1.5;--sidebar-width: 260px;--bg-primary: #0d0d0d;--bg-secondary: #171717;--bg-sidebar: #111111;--bg-hover: #1e1e1e;--bg-input: #1e1e1e;--text-primary: #ececec;--text-secondary: #8e8e8e;--border-color: #2a2a2a;--accent: #10a37f;--accent-hover: #0e8c6d}*{box-sizing:border-box;margin:0;padding:0}html,body,#root{height:100%;background:var(--bg-primary);color:var(--text-primary)}.app{display:flex;height:100vh;overflow:hidden}.main{flex:1;display:flex;flex-direction:column;min-width:0}.sidebar-overlay{display:none}.sidebar{width:var(--sidebar-width);background:var(--bg-sidebar);border-right:1px solid var(--border-color);display:flex;flex-direction:column;flex-shrink:0;height:100vh;overflow:hidden}.new-chat-btn{display:flex;align-items:center;gap:10px;margin:12px;padding:12px 16px;background:transparent;border:1px solid var(--border-color);border-radius:8px;color:var(--text-primary);font-size:.9rem;cursor:pointer;transition:background .15s}.new-chat-btn:hover{background:var(--bg-hover)}.conversations-list{flex:1;overflow-y:auto;padding:4px 8px}.conversation-item{display:flex;align-items:center;gap:10px;padding:10px 12px;border-radius:8px;cursor:pointer;font-size:.875rem;color:var(--text-secondary);transition:background .15s;position:relative}.conversation-item:hover,.conversation-item.active{background:var(--bg-hover);color:var(--text-primary)}.conversation-title{flex:1;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.delete-btn{opacity:0;background:none;border:none;color:var(--text-secondary);cursor:pointer;padding:4px;border-radius:4px;display:flex;align-items:center;transition:opacity .15s,color .15s}.conversation-item:hover .delete-btn{opacity:1}.delete-btn:hover{color:#ef4444}.topbar{display:flex;align-items:center;gap:12px;padding:12px 16px;border-bottom:1px solid var(--border-color);background:var(--bg-primary);flex-shrink:0}.menu-btn{display:none;background:none;border:none;color:var(--text-primary);cursor:pointer;padding:4px;border-radius:4px}.menu-btn:hover{background:var(--bg-hover)}.topbar-title{font-size:.95rem;font-weight:600;color:var(--text-primary)}.chat-area{flex:1;overflow-y:auto;display:flex;justify-content:center}.messages{width:100%;max-width:768px;padding:24px 16px;display:flex;flex-direction:column;gap:24px}.chat-empty{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:16px;color:var(--text-secondary)}.chat-empty h2{font-size:1.4rem;font-weight:500;color:var(--text-primary)}.chat-empty-icon{opacity:.5}.message{display:flex;gap:16px;line-height:1.7}.message-avatar{width:32px;height:32px;border-radius:50%;display:flex;align-items:center;justify-content:center;flex-shrink:0;margin-top:2px}.message.user .message-avatar{background:#5b6feb;color:#fff}.message.assistant .message-avatar{background:var(--accent);color:#fff}.message-content{font-size:.95rem;color:var(--text-primary);white-space:pre-wrap;word-break:break-word}.cursor{animation:blink .8s step-end infinite;color:var(--accent);font-weight:300}@keyframes blink{50%{opacity:0}}.input-area{padding:16px 16px 24px;display:flex;flex-direction:column;align-items:center;flex-shrink:0}.input-container{width:100%;max-width:768px;background:var(--bg-input);border:1px solid var(--border-color);border-radius:16px;display:flex;align-items:flex-end;padding:12px 16px;gap:8px;transition:border-color .15s}.input-container:focus-within{border-color:var(--accent)}.input-container textarea{flex:1;background:none;border:none;color:var(--text-primary);font-size:.95rem;font-family:inherit;line-height:1.5;resize:none;outline:none;max-height:200px;min-height:24px}.input-container textarea::placeholder{color:var(--text-secondary)}.send-btn{width:36px;height:36px;border-radius:50%;background:var(--accent);border:none;color:#fff;cursor:pointer;display:flex;align-items:center;justify-content:center;flex-shrink:0;transition:background .15s,opacity .15s}.send-btn:hover:not(:disabled){background:var(--accent-hover)}.send-btn:disabled{opacity:.4;cursor:default}.input-hint{font-size:.75rem;color:var(--text-secondary);margin-top:8px;text-align:center}::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:#333;border-radius:3px}::-webkit-scrollbar-thumb:hover{background:#444}@media(max-width:768px){.sidebar{position:fixed;left:-100%;top:0;z-index:100;transition:left .25s ease}.sidebar.open{left:0}.sidebar-overlay{display:block;position:fixed;top:0;right:0;bottom:0;left:0;background:#00000080;z-index:99}.menu-btn{display:flex}}