*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
 body{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,sans-serif;background:#f5f5f5;color:#222;min-height:100vh}
 .login-container{display:flex;align-items:center;justify-content:center;min-height:100vh}
 .login-box{background:#fff;padding:40px;border-radius:8px;box-shadow:0 2px 12px rgba(0,0,0,0.08);width:360px}
 .login-box h1{font-size:20px;margin-bottom:24px;text-align:center}
 .login-box input{width:100%;padding:10px 12px;border:1px solid #ddd;border-radius:4px;font-size:14px;margin-bottom:12px}
 .login-box button{width:100%;padding:10px;background:#1a73e8;color:#fff;border:none;border-radius:4px;font-size:14px;cursor:pointer}
 .login-box button:hover{background:#1557b0}
 .login-error{color:#d32f2f;font-size:13px;margin-top:8px;display:none}
 .app{display:none}
 .app.visible{display:flex;flex-direction:column;height:100vh}
 .topbar{background:#fff;padding:0 24px;height:52px;display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid #e0e0e0;flex-shrink:0}
 .topbar .logo{font-size:16px;font-weight:600}
 .topbar .nav{display:flex;gap:4px}
 .topbar .nav a{padding:8px 16px;text-decoration:none;color:#555;font-size:14px;border-radius:4px}
 .topbar .nav a:hover{background:#f0f0f0}
 .topbar .nav a.active{background:#e8f0fe;color:#1a73e8}
 .topbar .user-area{font-size:13px;color:#888;display:flex;align-items:center;gap:12px}
 .topbar .user-area button{background:none;border:1px solid #ddd;padding:4px 12px;border-radius:4px;font-size:13px;cursor:pointer}
 .main-content{flex:1;overflow:auto;padding:24px;max-width:1200px;margin:0 auto;width:100%}
 .page{display:none}
 .page.active{display:block}
 .upload-zone{border:2px dashed #ccc;border-radius:12px;padding:60px 20px;text-align:center;cursor:pointer;background:#fafafa;transition:border-color .2s}
 .upload-zone:hover,.upload-zone.drag-over{border-color:#1a73e8;background:#e8f0fe}
 .upload-zone input{display:none}
 .upload-zone .icon{font-size:48px;margin-bottom:12px}
 .upload-zone .hint{font-size:14px;color:#888}
 .upload-list{margin-top:24px}
 .upload-item{display:flex;align-items:center;padding:12px 16px;background:#fff;border-radius:6px;margin-bottom:8px;box-shadow:0 1px 3px rgba(0,0,0,0.06)}
 .upload-item .name{flex:1;font-size:14px;margin-right:16px}
 .upload-item .status{font-size:13px}
 .upload-item .status.success{color:#2e7d32}
 .upload-item .status.error{color:#d32f2f}
 .upload-item .status.uploading{color:#1a73e8}
 .file-list-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:16px}
 .file-list-header h2{font-size:18px}
 .filter-bar{display:flex;gap:8px;margin-bottom:16px;flex-wrap:wrap}
 .filter-bar select{padding:6px 10px;border:1px solid #ddd;border-radius:4px;font-size:13px}
 .file-card{background:#fff;padding:16px;border-radius:6px;margin-bottom:8px;box-shadow:0 1px 3px rgba(0,0,0,0.06);display:flex;align-items:flex-start;gap:16px}
 .file-card .file-icon{font-size:28px;flex-shrink:0}
 .file-card .file-info{flex:1;min-width:0}
 .file-card .file-title{font-size:15px;font-weight:500;margin-bottom:4px}
 .file-card .file-meta{font-size:12px;color:#888}
 .file-card .file-tags{display:flex;gap:4px;margin-top:6px;flex-wrap:wrap}
 .file-card .file-tags span{background:#e8f0fe;color:#1a73e8;padding:2px 8px;border-radius:10px;font-size:11px}
 .file-card .file-actions{flex-shrink:0}
 .file-card .file-actions button{background:none;border:none;color:#d32f2f;cursor:pointer;font-size:13px}
 .pagination{display:flex;justify-content:center;gap:8px;margin-top:16px}
 .pagination button{padding:6px 14px;border:1px solid #ddd;background:#fff;border-radius:4px;cursor:pointer;font-size:13px}
 .pagination button:disabled{opacity:.4;cursor:default}
 .search-box{margin-bottom:24px}
 .search-box textarea{width:100%;padding:14px;border:1px solid #ddd;border-radius:8px;font-size:15px;resize:none;height:80px;font-family:inherit}
 .search-box button{margin-top:10px;padding:10px 28px;background:#1a73e8;color:#fff;border:none;border-radius:6px;font-size:14px;cursor:pointer}
 .search-box button:hover{background:#1557b0}
 .search-answer{background:#fff;padding:20px;border-radius:8px;margin-bottom:16px;box-shadow:0 1px 3px rgba(0,0,0,0.06);line-height:1.7}
 .search-answer h3{font-size:15px;margin-bottom:8px;color:#1a73e8}
 .search-files h3{font-size:14px;margin-bottom:12px}
 #graph-container{width:100%;height:calc(100vh - 160px);border:1px solid #e0e0e0;border-radius:8px;background:#fff}
.toast{position:fixed;top:20px;right:20px;padding:12px 20px;background:#333;color:#fff;border-radius:6px;font-size:13px;z-index:999;animation:fadeIn .3s}
 .answer-body p{margin:0 0 10px 0;line-height:1.7}
 .answer-body strong{color:#222}
 .answer-body ul{margin:8px 0;padding-left:20px}
 .answer-body li{margin:4px 0;line-height:1.6}
@keyframes fadeIn{from{opacity:0;transform:translateY(-10px)}to{opacity:1;transform:translateY(0)}}