body{margin:0;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,sans-serif}.chat-layout{display:flex;height:100vh}.sidebar{width:260px;background:#f9f9f9;border-right:1px solid #eee;flex-shrink:0;overflow-y:auto;display:flex;flex-direction:column}.sidebar.collapsed{width:0;overflow:hidden;border-right:none}.sidebar-header{padding:12px 16px;border-bottom:1px solid #eee}.sidebar-list{flex:1;overflow-y:auto}.sidebar-date-group{padding:4px 16px;font-size:12px;color:#999;margin-top:8px}.sidebar-item{padding:8px 16px;cursor:pointer;border-radius:6px;margin:2px 8px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:14px;display:flex;align-items:center;justify-content:space-between}.sidebar-item:hover{background:#eee}.sidebar-item.active{background:#e6f4ff}.sidebar-item .delete-btn{opacity:0;transition:opacity .2s;flex-shrink:0}.sidebar-item:hover .delete-btn{opacity:1}.sidebar-footer{padding:12px 16px;border-top:1px solid #eee;display:flex;align-items:center;justify-content:space-between}.chat-main{flex:1;display:flex;flex-direction:column;min-width:0}.chat-header{height:48px;border-bottom:1px solid #eee;display:flex;align-items:center;padding:0 16px;font-weight:600;gap:12px}.message-list{flex:1;overflow-y:auto;padding:16px}.message-list-empty{display:flex;align-items:center;justify-content:center;height:100%;color:#999;font-size:15px}.message{margin-bottom:16px;max-width:800px;margin-left:auto;margin-right:auto}.message-user{text-align:right}.message-user .message-content{background:#1677ff;color:#fff;display:inline-block;padding:8px 16px;border-radius:16px;max-width:70%;text-align:left;word-break:break-word;line-height:1.6}.message-assistant .message-content{background:#f0f0f0;display:inline-block;padding:12px 16px;border-radius:16px;max-width:85%;text-align:left;word-break:break-word;line-height:1.6}.message-assistant .message-content p{margin:0 0 8px}.message-assistant .message-content p:last-child{margin-bottom:0}.message-assistant .message-content table{border-collapse:collapse;width:100%;margin:8px 0}.message-assistant .message-content th,.message-assistant .message-content td{border:1px solid #ddd;padding:6px 10px;text-align:left;font-size:13px}.message-assistant .message-content th{background:#f5f5f5;font-weight:600}.message-assistant .message-content pre{background:#1e1e1e;color:#d4d4d4;padding:12px;border-radius:8px;overflow-x:auto;font-size:13px}.message-assistant .message-content code{background:#e8e8e8;padding:1px 4px;border-radius:3px;font-size:13px}.message-assistant .message-content pre code{background:none;padding:0}.message-assistant .message-content ul,.message-assistant .message-content ol{padding-left:20px;margin:4px 0}.msg-actions{display:flex;gap:4px;margin-top:6px;opacity:0;transition:opacity .2s}.message-assistant:hover .msg-actions{opacity:1}.msg-action-btn{display:inline-flex;align-items:center;gap:4px;padding:2px 6px;border:none;background:none;color:#999;cursor:pointer;font-size:13px;border-radius:4px;transition:all .15s}.msg-action-btn:hover{color:#555;background:#e8e8e8}.msg-action-btn.copied{color:#52c41a}.msg-action-label{font-size:12px}.chat-input-area{border-top:1px solid #eee;padding:12px 16px;max-width:800px;margin:0 auto;width:100%;box-sizing:border-box}.chat-input-wrapper{display:flex;gap:8px}.typing-indicator{display:inline-flex;gap:4px;padding:4px 0}.typing-dot{width:6px;height:6px;background:#999;border-radius:50%;animation:pulse 1.5s infinite}.typing-dot:nth-child(2){animation-delay:.3s}.typing-dot:nth-child(3){animation-delay:.6s}@keyframes pulse{0%,to{opacity:.3}50%{opacity:1}}.download-link{display:inline-flex;align-items:center;gap:4px;color:#1677ff;text-decoration:none;padding:4px 8px;background:#f0f7ff;border-radius:4px;margin-top:4px}.download-link:hover{background:#e0efff}.example-questions{max-width:680px;margin:0 auto;padding:60px 16px 40px}.welcome-section{text-align:center;margin-bottom:32px}.welcome-icon{font-size:48px;margin-bottom:12px;line-height:1}.welcome-title{font-size:22px;font-weight:600;color:#1a1a1a;margin:0 0 8px}.welcome-subtitle{font-size:14px;color:#888;margin:0;line-height:1.6}.category-tabs{display:flex;gap:10px;justify-content:center;margin-bottom:20px;flex-wrap:wrap}.category-tab{padding:8px 20px;border-radius:20px;border:1px solid #e0e0e0;background:#fff;cursor:pointer;font-size:14px;color:#555;transition:all .2s;display:flex;align-items:center;gap:6px}.category-tab:hover{border-color:#1677ff;color:#1677ff;transform:translateY(-1px);box-shadow:0 2px 6px #1677ff1f}.category-tab.active{background:#1677ff;color:#fff;border-color:#1677ff;box-shadow:0 2px 8px #1677ff40}.category-icon{font-size:16px}.question-list{display:flex;flex-direction:column;gap:10px}.question-card{padding:14px 20px;border:1px solid #eee;border-radius:10px;background:#fff;cursor:pointer;font-size:15px;color:#333;transition:all .2s;display:flex;align-items:center;justify-content:space-between}.question-card:hover{border-color:#1677ff;background:#f0f7ff;transform:translate(4px)}.question-card:hover .question-arrow{color:#1677ff;transform:translate(3px)}.question-text{flex:1}.question-arrow{color:#ccc;font-size:16px;transition:all .2s;margin-left:12px;flex-shrink:0}.skeleton-tab{width:80px;height:36px;background:linear-gradient(90deg,#f0f0f0 25%,#e0e0e0,#f0f0f0 75%);background-size:200% 100%;animation:skeleton-shimmer 1.5s infinite}.skeleton-card{height:52px;background:linear-gradient(90deg,#f0f0f0 25%,#e0e0e0,#f0f0f0 75%);background-size:200% 100%;animation:skeleton-shimmer 1.5s infinite}@keyframes skeleton-shimmer{0%{background-position:200% 0}to{background-position:-200% 0}}@media(max-width:768px){.sidebar{position:absolute;z-index:100;height:100%;background:#fff}.sidebar.collapsed{display:none}.message-user .message-content{max-width:85%}.message-assistant .message-content{max-width:95%}}