:root{--bg-sidebar:#171717;--bg-main:#212121;--bg-input:#2f2f2f;--bg-hover:#2a2a2a;--bg-user-bubble:#2f2f2f;--text-primary:#ececec;--text-secondary:#a0a0a0;--border-color:#2f2f2f;--accent:#10a37f}*{box-sizing:border-box;margin:0;padding:0}html,body,#root{height:100%}body{background:var(--bg-main);color:var(--text-primary);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Helvetica,Arial,sans-serif;overflow:hidden}::-webkit-scrollbar{width:8px}::-webkit-scrollbar-thumb{background:#444;border-radius:4px}::-webkit-scrollbar-track{background:0 0}.app{height:100vh;display:flex}.sidebar{background:var(--bg-sidebar);flex-direction:column;flex-shrink:0;width:260px;transition:margin-left .2s;display:flex}.sidebar.collapsed{margin-left:-260px}.sidebar-header{gap:8px;padding:12px;display:flex}.new-chat-btn{border:1px solid var(--border-color);color:var(--text-primary);cursor:pointer;background:0 0;border-radius:10px;flex:1;align-items:center;gap:10px;padding:10px 12px;font-size:14px;transition:background .15s;display:flex}.new-chat-btn:hover{background:var(--bg-hover)}.icon-btn{width:36px;height:36px;color:var(--text-primary);cursor:pointer;background:0 0;border:none;border-radius:8px;justify-content:center;align-items:center;display:flex}.icon-btn:hover{background:var(--bg-hover)}.conversation-list{flex:1;padding:8px;overflow-y:auto}.conv-section-label{color:var(--text-secondary);padding:8px 8px 4px;font-size:12px}.conv-item{cursor:pointer;white-space:nowrap;text-overflow:ellipsis;border-radius:8px;align-items:center;margin-bottom:2px;padding:10px;font-size:14px;display:flex;overflow:hidden}.conv-item:hover,.conv-item.active{background:var(--bg-hover)}.sidebar-footer{color:#fff;border-top:1px solid #333;padding:20px}.sidebar-footer h3{margin:0 0 10px;font-size:14px;font-weight:600}.sidebar-footer p{color:#aaa;margin:0 0 16px;font-size:10px;line-height:1.4}.login-btn{color:#fff;cursor:pointer;background:0 0;border:1px solid #555;border-radius:999px;width:100%;padding:10px}.login-btn:hover{background:#222}.avatar{background:linear-gradient(135deg,#10a37f,#1a7f64);border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:28px;height:28px;font-size:13px;font-weight:600;display:flex}.main{flex-direction:column;flex:1;min-width:0;display:flex;position:relative}.top-bar{flex-shrink:0;align-items:center;gap:10px;padding:12px 16px;display:flex}.model-selector{cursor:pointer;border-radius:8px;align-items:center;gap:6px;padding:6px 10px;font-size:14px;font-weight:600;display:flex}.model-selector:hover{background:var(--bg-hover)}.model-selector .sub{color:var(--text-secondary);font-size:12px;font-weight:400}.chat-scroll{flex-direction:column;flex:1;align-items:center;display:flex;overflow-y:auto}.chat-inner{width:100%;max-width:720px;padding:24px 16px 140px}.empty-state{text-align:center;flex-direction:column;justify-content:center;align-items:center;gap:20px;height:100%;min-height:60vh;padding:0 20px;display:flex}.empty-state h1{font-size:28px;font-weight:600}.suggestion-grid{grid-template-columns:1fr 1fr;gap:10px;width:100%;max-width:560px;display:grid}.suggestion-card{background:var(--bg-input);border:1px solid var(--border-color);text-align:left;cursor:pointer;border-radius:12px;padding:14px;font-size:13px;transition:background .15s}.suggestion-card:hover{background:var(--bg-hover)}.suggestion-card .title{margin-bottom:4px;font-weight:500}.suggestion-card .desc{color:var(--text-secondary)}.message{gap:16px;margin-bottom:28px;animation:.25s fadeIn;display:flex}@keyframes fadeIn{0%{opacity:0;transform:translateY(6px)}to{opacity:1;transform:translateY(0)}}.message.user{justify-content:flex-end}.message.user .bubble{background:var(--bg-user-bubble);white-space:pre-wrap;border-radius:20px;max-width:70%;padding:10px 16px}.message.user{flex-direction:column;align-items:flex-end;gap:8px;display:flex}.message.user .pdf{color:#f3f3f3;cursor:pointer;background:#2b2b2b;border:1px solid #3f3f3f;border-radius:14px;align-items:center;width:260px;max-width:320px;padding:10px 14px;font-size:14px;font-weight:500;transition:all .2s;display:flex}.message.assistant{align-items:flex-start}.msg-avatar-pdf{background:linear-gradient(135deg,#fff,#171717);border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:30px;height:30px;font-size:14px;display:flex}.msg-avatar{background:linear-gradient(135deg,#10a37f,#0d8a6c);border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:30px;height:30px;font-size:14px;display:flex}.msg-content{white-space:pre-wrap;padding-top:4px;font-size:15px;line-height:1.7}.msg-error{color:#f87171}.video-recommendations{flex-wrap:wrap;gap:10px;margin-top:12px;display:flex}.video-card{border:1px solid var(--border,#2a2a2a);width:240px;color:inherit;border-radius:10px;align-items:center;gap:10px;padding:8px;text-decoration:none;transition:background .15s;display:flex}.video-card:hover{background:#ffffff0d}.video-card img{object-fit:cover;border-radius:6px;flex-shrink:0;width:64px;height:48px}.video-card-info{min-width:0}.video-card-title{text-overflow:ellipsis;-webkit-line-clamp:2;-webkit-box-orient:vertical;font-size:13px;line-height:1.3;display:-webkit-box;overflow:hidden}.video-card-channel{color:var(--text-secondary);margin-top:2px;font-size:11px}.typing-dots{gap:4px;padding:8px 0;display:flex}.typing-dots span{background:var(--text-secondary);border-radius:50%;width:7px;height:7px;animation:1.2s ease-in-out infinite bounce}.typing-dots span:nth-child(2){animation-delay:.15s}.typing-dots span:nth-child(3){animation-delay:.3s}@keyframes bounce{0%,60%,to{opacity:.5;transform:translateY(0)}30%{opacity:1;transform:translateY(-5px)}}:root{--sidebar-width:260px;--sidebar-collapsed-width:80px}.input-area{left:var(--sidebar-width);background:linear-gradient(to top, var(--bg-main) 70%, transparent);z-index:100;justify-content:center;padding:12px 20px 20px;transition:left .25s;display:flex;position:fixed;bottom:0;right:0}.input-area.collapsed{left:var(--sidebar-collapsed-width)}.input-wrapper{background:var(--bg-input);border:1px solid var(--border-color);border-radius:26px;align-items:flex-end;gap:16px;width:100%;max-width:720px;padding:8px 8px 8px 18px;display:flex}.input-wrapper textarea{resize:none;color:var(--text-primary);background:0 0;border:none;outline:none;flex:1;max-height:200px;padding:8px 0;font-family:inherit;font-size:15px;line-height:1.5}.input-wrapper textarea::placeholder{color:var(--text-secondary)}.send-btn{background:var(--text-primary);cursor:pointer;border:none;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:36px;height:36px;transition:opacity .15s;display:flex}.send-btn:disabled{opacity:.3;cursor:default}.send-btn svg{width:16px;height:16px}.disclaimer{text-align:center;color:var(--text-secondary);margin-top:8px;font-size:12px}.plus-btn{color:#a0a0a0;cursor:pointer;background:#2f2f2f;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:32px;height:32px;font-size:22px;font-weight:300;display:flex}.plus-btn:hover{background:#2f2f2f}.pdf-div{width:100px;height:10px}.file-preview-container{flex-wrap:wrap;gap:10px;margin-bottom:10px;display:flex}.file-preview{background:#2f2f2f;border:1px solid #ddd;border-radius:14px;align-items:center;gap:10px;max-width:260px;padding:8px 12px;display:flex}.file-name{white-space:nowrap;text-overflow:ellipsis;font-size:14px;font-weight:500;overflow:hidden}.file-size{color:#777;font-size:12px}.remove-file{cursor:pointer;color:#666;background:0 0;border:none;border-radius:50%;width:24px;height:24px;font-size:18px}.remove-file:hover{background:#ddd}